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TABLE OF CONTENTS
CAPSTONE TURBINE CORPORATION AND SUBSIDIARY INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Table of Contents

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

Commission file number 001-15957

CAPSTONE TURBINE CORPORATION
(Exact name of registrant as specified in its charter)

(818)734-5300
(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

          Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes o    No ý

          Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o    No ý

          Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý    No o

          Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes o    No o

          Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. o

          Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

          Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o    No ý

          The aggregate market value of the shares of Common Stock of the registrant held by non-affiliates on September 30, 2009 was approximately $258.9 million.

          As of June 7, 2010, 242,231,935 shares of the registrant's Common Stock were issued and outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

          Portions of the definitive proxy statement relating to the registrant's 2010 annual meeting of stockholders are incorporated by reference into Part III of this report to the extent described therein.

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CAPSTONE TURBINE CORPORATION

FORM 10-K

TABLE OF CONTENTS

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PART I

Item 1.    Business.

Overview

        Capstone Turbine Corporation ("Capstone" or the "Company") develops, manufactures, markets and services microturbine technology solutions for use in stationary distributed power generation applications, including cogeneration (combined heat and power ("CHP"), integrated combined heat and power ("ICHP"), and combined cooling, heat and power ("CCHP")), resource recovery and secure power. In addition, our microturbines can be used as battery charging generators for hybrid electric vehicle applications. Microturbines allow customers to produce power on-site in parallel with the electric grid or stand alone when no utility grid is available. There are several technologies that are used to provide "on-site power generation" (also called "distributed generation") such as reciprocating engines, solar power, wind powered systems and fuel cells. For customers who do not have access to the electric utility grid, microturbines provide clean, on-site power with lower scheduled maintenance intervals and greater fuel flexibility than competing technologies. For customers with access to the electric grid, microturbines provide an additional source of continuous duty power, thereby providing additional reliability and potential cost savings. With our stand-alone feature, customers can produce their own energy in the event of a power outage and can use microturbines as their primary source of power for extended periods. Because our microturbines also produce clean, usable heat energy, they provide economic advantages to customers who can benefit from the use of hot water, chilled water, air conditioning and heating. Our microturbines are sold primarily through our distributors. Our distributors, along with our Authorized Service Companies ("ASCs"), install the microturbines. Service is provided directly by us through our Factory Protection Plan ("FPP") or by our distributors and ASCs. Successful implementation of microturbines relies on the quality of the microturbine, marketability for appropriate applications, and the quality of the installation and support.

        We believe we were the first company to offer a commercially available power source using microturbine technology. Capstone offers microturbines designed for commercial, industrial, and utility users from 30 kilowatts ("kW") up to 1 megawatt in electric power output. Our 30 kW ("C30") microturbine can produce enough electricity to power a small convenience store. The 60 kW and 65 kW ("C60 Series") microturbine can produce enough heat to provide hot water to a 100-room hotel while also providing about one-third of its electrical requirements. Our 200 kW ("C200") microturbine is well suited for larger hotels, office buildings, and wastewater treatment plants, among others. By packaging the C200 microturbine power modules into an International Organization for Standardization ("ISO") sized container, Capstone has created a family of microturbine offerings from 600 kW up to one megawatt in a compact footprint. Our 1000 kW ("C1000 Series") microturbines are well suited for utility substations, larger commercial and industrial facilities and remote oil and gas applications. Our microturbines combine patented air-bearing technology, advanced combustion technology and sophisticated power electronics to form efficient and ultra low emission electricity and cooling and heat production systems. Because of our air-bearing technology, our microturbines do not require liquid lubricants. This means they do not require routine maintenance to change and dispose of oil or other liquid lubricants, as do the most common competing products. Capstone microturbines can be fueled by various sources, including natural gas, propane, sour gas, renewable fuels such as landfill or digester gas, kerosene, diesel and biodiesel. The C60 Series and C200 microturbines are available with integrated heat exchangers, making them easy to engineer and install in applications where hot water is used. Our products produce exceptionally clean power. Our C60 Series was certified by the California Air Resources Board ("CARB") as meeting its stringent 2007 emissions requirements—the same emissions standard used to certify fuel cells and the same emissions levels as a state-of-the-art central power plant. Our C65 Landfill and Digester Gas systems were certified in January 2008 by CARB as meeting 2008 waste gas emissions requirements for landfill and digester gas applications.

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        On February 1, 2010, we acquired the 100 kW ("TA100") microturbine product line from Calnetix Power Solutions, Inc. ("CPS") and entered into a manufacturing sub-contract agreement and an original equipment manufacturer agreement with selected exclusive rights to package a combined microturbine and waste heat recovery generator product. The TA100 microturbine is most similar to the Capstone product design compared to other microturbine products in the industry and the 100 kW rating fits well between our C60 Series and C200 microturbines. The 125 kW waste heat recovery generator can be directly fired by the exhaust of six C60 Series or two C200 microturbines to provide a total of over 500 kW of clean and efficient green power in applications where the microturbine exhaust is not otherwise utilized, such as CHP or CCHP.

        We sell complete microturbine units, subassemblies, components and various accessories. We also remanufacture microturbine engines and provide after-market parts and services. Our microturbines are sold primarily through distributors and Original Equipment Manufacturers ("OEMs"). Distributors purchase our products for sale to end users and also provide application engineering and installation support. Distributors are also required to provide a variety of additional services, including engineering the applications in which the microturbines will be used, installation support of the products at the end users' sites, commissioning the installed applications and providing post-commissioning service. Our distributors perform as value-added resellers. OEMs integrate Capstone's products into their own product solutions. Capstone has also established outside sales representatives who qualify and close customer orders for direct sales by Capstone.

        To assure proper installation of Capstone microturbine systems, we have instituted a Factory Trained Installer ("FTI") training and certification program. Personnel from our distributors and OEMs, as well as design engineering firms, contractors and end users attend this FTI training. We offer a Conceptual Approval ("CA") process to assist all customers by reviewing their installation designs to confirm that the technical requirements for proper operation have been met, such as electrical interconnections, load requirements, fuel type and pressure, cooling air flow, and turbine exhaust routing. As part of the microturbine commissioning process, we also receive a checklist to confirm that the final installation adheres to Capstone technical requirements before we accept any warranty obligations. This is aimed at providing the end user with a proper installation that will operate as expected for the life of the equipment.

        Capstone has a factory direct service offering for commissioning and post-commissioning service. We offer a comprehensive FPP where Capstone charges a fixed annual fee to perform scheduled maintenance, and in some cases unscheduled maintenance as well. Capstone then performs the required maintenance directly with its own personnel or contracts with one of its local ASCs to do so. Capstone provides factory and on-site training to certify all personnel that are allowed to perform service on our microturbines. Individuals who are certified are called Authorized Service Providers ("ASPs") and must be employed by an ASC in order to perform work pursuant to a Capstone FPP. The majority of our distributors are ASCs. We also have ASCs who do not sell our products, but only offer service for them.

Our Products

        We began commercial sales of our C30 products in 1998, targeting the emerging distributed generation industry that was being driven by fundamental changes in power requirements. In September 2000, we shipped the first commercial unit of our C60 Series microturbine. We began shipping the C60 Integrated CHP solution in 2003, and first shipments of the C65 models occurred during the quarter ended March 31, 2006. The first commercial C200 microturbine was shipped on August 28, 2008. Our C1000 Series product was developed based on Capstone's C200 microturbine engine. The C1000 Series product can be configured into 1,000 kW, 800 kW and 600 kW solutions in a single ISO-sized container. Our C1000 Series product beta testing was successfully implemented during

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Fiscal 2009 and the first commercial shipment was on December 29, 2008. We began shipping TA100 microturbines in March 2010.

        During Fiscal 2010, we booked total orders of $73.5 million for 620 units, or 77.2 megawatts, compared to $66.0 million for 673 units, or 76.6 megawatts, during Fiscal 2009. We shipped 499 units with an aggregate of 52.8 megawatts, generating revenue of $48.7 million compared to 494 units with an aggregate of 34.1 megawatts, generating revenue of $32.4 million during Fiscal 2009. Total backlog as of March 31, 2010 increased $24.8 million, or 40%, to $86.3 million from $61.5 million at March 31, 2009. On March 31, 2010, we had 726 units, or 96.4 megawatts, in total backlog compared to 605 units, or 72.0 megawatts, for the same period last year. As of March 31, 2010, all of the backlog was current and expected to be shipped within the next twelve months compared to 421 units, or 53.5 megawatts, valued at $45.3 million as of March 31, 2009. The timing of shipments is subject to change based on several variables (including customer payments and changes in customer delivery schedules), many of which are not in our control and can affect our revenue and backlog.

        The following table summarizes our backlog:

        Capstone microturbines are compact, lightweight and environmentally friendly generators of electricity and heat, compared to other competing technologies. They operate on the same principle as a jet engine with the added capability of using a variety of commercially available fuels. For example, our microturbines can operate on low British Thermal Unit ("BTU") gas, which is gas with lower energy content, and can also operate on gas with a high amount of sulfur, known in the industry as sour gas. Examples of these fuel sources include methane from facilities such as wastewater treatment plants, landfills or agrodigesters.

        Our microturbines incorporate four major design features:

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advanced combustion technology;



•

patented air-bearing technology;

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digital power electronics; and



•

remote monitoring.

        Our advanced combustion technology allows Capstone microturbines to achieve low emissions capability with a design that is simple to manufacture. These low emission levels not only provide an environmentally friendly product, but also eliminate permitting requirements in several municipalities for continuously operated onsite power generation. The air-bearing system allows the microturbine's single moving assembly to produce power without the need for typical petroleum-based lubrication. Air-bearings use a high-pressure field of air rather than petroleum lubricants. This improves reliability and reduces maintenance such as oil changes. The electronic controls manage critical functions and monitor operations of the microturbine. For instance, our electronics control the microturbine's speed, temperature and fuel flow and communicate with external networks and building management systems. The power electronics coordinate with the grid when the units are operated in a grid-connect mode and with the on-board battery when equipped for stand-alone mode. All control functions are performed digitally. Performance is optimized, resulting in lower emissions, higher reliability and high efficiency over a variable power range.

        The electrical output of our units can be paralleled in multiple unit configurations through our Advanced Power Server product and a digital communications cable to serve larger installations requiring electrical loads up to ten megawatts.

        Our products can operate:

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connected to the electric utility grid as a current source;



•

on a stand-alone basis as a voltage source;



•

multipacked to support larger loads as a "virtual single" unit; and



•

in dual mode, where the microturbine operates connected to the electric utility grid or operates independently.

        We also offer C60 Series and C200 ICHP systems. These systems combine the standard C60 Series and C200 microturbine unit with a Heat Recovery Module that provides electricity and heats water.

        Our family of products is offered in the following configurations:

        We offer various accessories for our products including rotary gas compressors with digital controls, heat recovery modules for CHP applications, dual mode controllers that allow automatic transition between grid connect and stand-alone modes, batteries with digital controls for stand-alone or dual-mode operations, power servers for large multipacked installations, protocol converters for Internet access, packaging options and miscellaneous parts such as frames, exhaust ducting and installation hardware. We also sell microturbine components and subassemblies to OEMs.

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        Our electronic controls manage microturbines using Capstone's proprietary software and advanced algorithms. The controls:

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start the turbogenerator and manage its load;



•

coordinate the functioning of the microturbine with the grid;



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manage the speed, fuel flow, and exhaust temperature of the microturbine;



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convert the variable frequency, up to a maximum of 1,600 Hertz, and variable voltage power produced by the generator into a usable output of either 50 or 60 Hertz AC or DC for HEV applications; and



•

provide digital communications to externally maintain and control the equipment.

        In addition, our proprietary Capstone Remote Monitoring Software ("CRMS") allows end users to remotely operate and manage the microturbine. Unlike the technology of other power sources that require manual monitoring and maintenance, the CRMS allows end-users to remotely and efficiently monitor performance, power generation and time of operation using our CRMS interface software with standard personal computers. This remote capability can provide end users with power generation flexibility and cost savings. Our Internet-based communication system, the Capstone Service Network ("CSN"), provides continuous remote monitoring and diagnostics to customers who purchase the service. If the CSN detects an out-of-limit condition or alarm, it automatically notifies the responsible ASC for immediate follow-up action.

        The C30 microturbines were initially designed to operate connected to an electric utility grid and to use a high pressure natural gas fuel source. We have expanded our microturbines' functionality to operate with different fuels. The combustor system remains the same for all fuels except for the fuel injectors, which currently vary between liquid and gaseous fuels. The Capstone microturbines' multi-fuel capability provides significant competitive advantages with respect to some of our selected vertical markets.

        Our C60 Series grid-connect and stand-alone microturbine power systems are listed by Underwriters Laboratories ("UL") as meeting the UL 2200 stationary engine generator standards and the UL 1741 utility interconnection requirements. Our products are manufactured by processes that are ISO 9001:2000 and ISO 14001:2004 certified.

        In 2002, the California Energy Commission certified our 30 kW and 60 kW microturbine power systems as the first products to comply with the requirements of its "Rule 21" grid interconnection standard. This standard streamlines the process for connecting distributed generation systems to the grid in California. The benefits of achieving this standard include avoiding both costly external equipment procurement requirements and extensive site-by-site and utility-by-utility analysis. Our protective relay functionality has also been recognized by the State of New York, which has pre-cleared our microturbines for connection to New York's electric utility grid.

        Our 60 kW microturbine power system was the first combustion power generation product to be certified by the CARB as meeting its stringent distributed generation emissions standards that went into effect in 2003. Our C60 Series microturbine now meets the even more stringent CARB 2007 standard for natural gas, as well as the 2008 CARB standard for landfill and digester gas fuels.

        The 100 kW microturbine power system offers a digital communications interface which can be connected to an external controller (not sold by Capstone) to provide multiple unit and dual mode dispatching functionality. An external synchronization board is provided to parallel the electrical output in multiple unit configurations for stand-alone operation.

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        We are the first microturbine manufacturer to achieve UL Class I, Division 2 certification for operation in hazardous-area oil and gas applications. These specially packed systems are applied in oil and gas production areas with potentially explosive environments.

        In September 2009, we received UL certification for our C200 Series grid-connect and stand-alone microturbine power systems as meeting the UL 2200 stationary engine generator standards and the UL 1741 utility interconnection requirements.

        In June 2010, we received UL certification for our C1000 Series grid-connect and stand-alone microturbine power systems as meeting the UL 2200 stationary engine generator standards and the UL 1741 utility interconnection requirements.

Applications

        Worldwide, stationary power generation applications vary from huge central stationary generating facilities above 1,000 megawatts, to back-up uses below ten kilowatts. Historically, power generation in most developed countries such as the United States, has been part of a regulated system. A number of developments related primarily to the deregulation of the industry as well as significant technology advances have broadened the range of power supply choices available to customers. With the introduction of the C200 and C1000 Series, our microturbines may be used in a variety of applications generally requiring less than five megawatts. Within the distributed generation markets served, we focus on vertical markets that we have identified as having the greatest near-term potential. In the markets we are focusing on (CHP, CCHP, resource recovery and secure power), we have identified specific targeted vertical market segments.

Cogeneration—CHP/CCHP

        Cogeneration maximizes the use of energy produced by the microturbines, reduces emissions compared with traditional power generation and enhances the economic advantage to customers. Cogeneration uses both the heat and electric energy produced in the power generation process. Using the heat and electricity created from a single combustion process increases the efficiency of the system from approximately 30% to 70% or more. The increased operating efficiency reduces overall green house gas emissions compared with traditional independent sources such as power generation and local thermal generation and, through displacement of other separate systems, can reduce variable production costs. Our microturbines' emissions of commonly found air pollutants ("criteria pollutants") such as Nitrogen oxides ("NOx") and volatile organic compounds ("VOCs") are lower than those from the on-site boilers that our CHP system displaces—meaning that local emissions of these pollutants are actually reduced when a Capstone CHP system is installed. This high CHP efficiency also means more efficient use of expensive fuels and can reduce net utility costs for end users. The most prominent uses of heat energy include space heating and air conditioning, heating and cooling water, as well as drying and other applications. For example, we have used the heat generated by the microturbines to supply hot water solutions for hotels, schools and swimming pools. When our microturbine exhaust drives an absorption chiller, the chiller produces chilled water for air conditioning and other uses. These systems have also been implemented to supply solutions in grocery stores, office and government buildings and manufacturing facilities.

        There are markets for CHP and CCHP applications worldwide. A study conducted for the US Department of Energy ("DOE") calculated the total potential CHP market in the United States to be over 35.5 gigawatts through 2020. Many governments have encouraged more efficient use of the power generation process to reduce pollution, lower dependence on fossil fuels and control the cost of locally produced goods. To access these markets, we have entered into agreements with distributors which have engineered CHP packages that utilize the hot exhaust air of the microturbine for heating water and

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also use the hot exhaust to run an absorption chiller for air conditioning. Further, we have our own integrated CHP product for the C60 Series and C200 products.

Resource Recovery/Renewable Fuels

        On a worldwide basis, there are thousands of locations where the production of fossil fuels and other extraction and production processes creates fuel byproducts, which traditionally have been released or burned into the atmosphere. Our microturbine products can use methane gases from landfills and wastewater treatment facilities and can burn these waste gases with minimal emissions, thereby, in some cases, avoiding the imposition of penalties incurred for pollution, while simultaneously producing electricity for use at the site or in the surrounding community. Our microturbine products have demonstrated effectiveness in this application and outperform conventional combustion engines in a number of situations, including when the gas contains a high amount of sulfur. We have sold systems that were installed in the resource recovery market to be used at oil and gas exploration and production sites both onshore and offshore in addition to landfills and wastewater treatment facilities. These gases are considered renewable resources.

        In February 2010, we entered into an agreement with CPS to purchase 125 kW waste heat recovery generators in exchange for certain minimum purchase requirements during a three-year period ending February 1, 2013. Pursuant to this agreement, we have exclusive rights to sell the zero-emission waste heat recovery generator for all microturbine applications and for applications 500 kW or lower where the source of heat is the exhaust of a reciprocating engine used in a landfill application.

Secure Power

        Because of the potentially catastrophic consequences of even momentary system failure, certain power users such as high technology and information systems companies require particularly high levels of reliability in their power service. Capstone's secure power offerings are the world's only microturbine powered Uninterruptible Power Source ("UPS") solutions that can offer clean, IT-grade power produced from microturbines, the utility or a combination of both. We offer two microturbine powered UPS solutions that support prime and dispatched power options. The Capstone UPSource microturbine powered UPS solution provides prime or emergency power solutions. Capstone's Hybrid UPS microturbine- powered solution provides power when dispatched in high efficiency, standard UPS and emergency power solutions. Both secure power products offer eight 9's of reliability (99.999999%) in common N + 1 configurations. Dual mode units operating in a prime power configuration can support a 150% overload for 10 seconds during transient conditions. Dual mode units operating in grid parallel mode can provide customers a back-up power system with an economic return. These systems offer high onsite energy efficiency when combined with a heat exchanger (CHP) to create hot water or with a chiller (CCHP) for air conditioning at these facilities. This configuration, when combined with the Capstone Dual Mode Controller, can transition from the grid parallel mode to prime power mode in less than 10 seconds. This provides end users with a backup system with a short return on investment.

Hybrid Electric Vehicles

        Our technology is also used in hybrid electric vehicle applications. Our customers have applied our products in hybrid electric vehicles such as buses and trolleys. In these applications the microturbine acts as an onboard battery charger to recharge the battery system as needed. The benefits of these microturbine hybrids include fuel economy gains, quieter operation, reduced emissions and high reliability compared with traditional combustion engines. Internal combustion diesel engine manufacturers have been challenged for the last several years to develop technology improvements, before after-treatment, that reduce emissions to levels specified by the EPA and CARB 2007 and 2010 standards. . Many manufacturers are incorporating exhaust treatment that increases upfront equipment costs, life cycle costs and may reduce overall engine efficiency.

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Sales, Marketing and Distribution

        We sell our microturbines worldwide. With the introduction of the C200 and C1000 Series products, management anticipates that our microturbines will be used in applications requiring up to five megawatts.

        We primarily sell our products through distributors, and in some cases, we sell our products directly to end users. Our parts are sold to distributors, ASCs and end users. Our typical terms of sale include shipment of the products with title, care, custody and control transferring at our dock, payment due anywhere from in advance of shipment to 90 days from shipment, and warranty periods of approximately 15 to 18 months from shipment. We typically do not have customer acceptance provisions in our agreements.

North America

        We have distribution agreements with a number of companies throughout North America for the resale of our products. Many of these distributors serve multiple markets in their select geographic regions. The primary markets served in this region have been CHP, CCHP, resource recovery, oil & gas and hybrid vehicles.

        In developing our sales opportunities we have identified the need to address various requirements present in our target localities. These requirements include electric grid interconnection standards, gas utility connection requirements, building and fire safety codes and various inspections and approvals. The costs and scheduling ramifications of these various approvals can be significant to the completion of an installation. Our goal is to work with the applicable regulating entities to establish compliant standards for the installation of our microturbines so that the costs and installation timelines are minimized for our customers. We have received pre-approval by the New York State Public Services Commission for installation and interconnection to the electric utilities in New York, and we meet the California interconnection requirements. Management believes that we can create market advantages for our products through enhancing the ease of deploying our distributed generation solutions.

        In February 2009, we introduced our factory rental program primarily to target the oil & gas and telecommunication sectors that frequently deploy temporary power solutions while they build out permanent infrastructure.

Asia and Australia

        Our sales and marketing strategy in Asia and Australia has been to develop and strengthen distributor relationships throughout these continents.

        Our market focus in Asia and Australia is CHP, CCHP and oil & gas applications. Our historical sales in Southeast Asia and Australia have primarily been in the oil & gas market. Other areas in Asia and the Pacific Rim offer attractive opportunities as well. South Korea and China are areas where resource recovery applications and CHP and CCHP solutions are expected to experience market growth.

Europe and Russia

        To address the European market, including Russia, we are strengthening our relationships with existing and new distributors and have increased Capstone local sales and service support. We have an office in Europe for the purpose of working with our distributors there on a daily basis to realize growth opportunities. We have established a spare parts distribution center in Europe to make parts readily available to our distributors. Resource recovery applications have been growing in Europe based on attractive incentives established in several countries. Further, Europe has a history of extensive use of distributed generation technologies.

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South America

        Our sales and marketing strategy in South America has been to develop and strengthen distributor relationships throughout South America.

        Our market focus in South America is CHP, CCHP and oil & gas applications. Our historical sales in South America have primarily been in the oil & gas market.

Revenue

        For geographic and segment revenue information, please see Note 2—Summary of Significant Accounting Policies—Segment Reporting in the "Notes to Consolidated Financial Statements."

Customers

        Two customers each accounted for 14% of revenue for the year ended March 31, 2010. Sales to Banking Production Centre ("BPC"), one of our Russian distributors, accounted for 14%, 13% and 18% of our revenue for the years ended March 31, 2010, 2009 and 2008, respectively. Sales to Aquatec-Maxcon Pty Ltd. ("Aquatec"), our Australian distributor, accounted for 14%, 5% and 0% of our revenue for the years ended March 31, 2010, 2009 and 2008, respectively. Sales to UTC Power Corporation ("UTCP"), an affiliate of United Technologies Corporation ("UTC") and historically one of our largest customers, accounted for 0.2%, 7% and 13% of our revenue for the years ended March 31, 2010, 2009 and 2008, respectively. Additionally, BPC and Green Environment, Inc. accounted for 20% and 16%, respectively, of net accounts receivable as of March 31, 2010. BPC accounted for 29% of net accounts receivable as of March 31, 2009. BPC represented 20% and 29% of net accounts receivable as of March 31, 2010 and 2009, respectively. UTCP did not have any invoices outstanding in accounts receivable as of March 31, 2010.

Competition

        The market for our products is highly competitive. Our microturbines compete with existing technologies such as reciprocating engines and may also compete with emerging distributed generation technologies, including solar power, wind-powered systems, fuel cells and other microturbines. Many potential customers rely on the utility grid for their electrical power. As many of our distributed generation competitors are large, well-established companies, they derive advantages from production economies of scale, worldwide presence and greater resources, which they can devote to product development or promotion.

        Generally, power purchased from the electric utility grid is less costly than power produced by distributed generation technologies, such as fuel cells or microturbines. Utilities may also charge fees to interconnect to their power grids. However, we can provide economic benefits to end users in instances where the waste heat from our microturbine has value (CHP and CCHP), where fuel costs are low (resource recovery/renewable fuels), where the costs of connecting to the grid may be high or impractical (such as remote power applications), where reliability and power quality are of critical importance, or in situations where peak shaving could be economically advantageous because of highly variable electricity prices. Because Capstone microturbines can provide a reliable source of power and can operate on multiple fuel sources, management believes they offer a level of flexibility not currently offered by other technologies such as reciprocating engines.

        Our reciprocating engine competitors have products and markets that are well developed and technologies that have been proven for some time. A reciprocating engine is also known as an internal combustion engine similar to those used in automotive applications. Reciprocating engines are popular for primary and back-up power applications despite higher levels of emissions, noise and maintenance. These technologies, which typically have a lower up-front cost than microturbines, are currently

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produced by, among others, Caterpillar Inc., Cummins Inc., Dresser Waukesha, a business unit of Dresser, Inc., GE Energy Jenbacher gas engines, Deutz Corporation and Kohler Power Systems, a division of Kohler Co.

        Our microturbines may also compete with other distributed generation technologies, including solar power, wind-powered systems and fuel cells. Solar-powered and wind-powered systems produce no emissions. The main drawbacks to solar-powered and wind-powered systems are their dependence on weather conditions, the utility grid and high capital costs that make these systems uneconomical without government subsidies. Although the market for fuel cells is still developing, a number of companies are focused on markets similar to ours, including FuelCell Energy Inc., UTCP, Plug Power Inc. and Ballard Power Systems Inc. Fuel cells have lower levels of NOx and other criteria pollutant emissions than our microturbines. Fuel cells, like wind-powered systems and solar power systems, have received higher levels of incentives for the same type of applications as microturbines. Management believes that, absent these high government-supported incentives, microturbines provide a better value to end users in most applications. However, over the medium-to-long term, fuel cell technologies that compete more directly with our products may be introduced.

        We also compete with other companies who have microturbine products, some of which have significantly greater resources and brand recognition than us, including Ingersoll-Rand Company Limited and Turbec S.p.A.

        Overall, we compete with end users' other options for electrical power and heat generation on the basis of our microturbines' ability to:

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provide power when a utility grid is not available or goes out of service;



•

reduce total cost of purchasing electricity and fuel;



•

improve electric power availability and provide high power quality;



•

operate on multiple fuel types;



•

reduce emissions—both criteria pollutants and greenhouse gasses;



•

simplify operation; and



•

control maintenance costs and associated disposal of hazardous materials.

Governmental and Regulatory Impact

        Our markets can be positively or negatively impacted by the effects of governmental and regulatory matters. We are affected not only by energy policy, laws, regulations and incentives of governments in the markets into which we sell, but also by rules, regulations and costs imposed by utilities. Utility companies or governmental entities could place barriers on the installation of our product or the interconnection of the product with the electric grid. Further, utility companies may charge additional fees to customers who install on-site power generation; thereby reducing the electricity they take from the utility, or for having the capacity to use power from the grid for back-up or standby purposes. These types of restrictions, fees or charges could hamper the ability to install or effectively use our product or increase the cost to our potential customers for using our systems. This could make our systems less desirable, thereby adversely affecting our revenue and profitability potential. In addition, utility rate reductions can make our products less competitive which would have a material adverse effect on our operations. These costs, incentives and rules are not always the same as those faced by technologies with which we compete. However, rules, regulations, laws and incentives could also provide an advantage to our distributed generation solutions as compared with competing technologies if we are able to achieve required compliance in a lower cost, more efficient manner. Additionally, reduced emissions and higher fuel efficiency could help our customers combat the effects of global

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warming. Accordingly, we may benefit from increased government regulations that impose tighter emission and fuel efficiency standards.

        In February 2009, the President of the United States signed into law the American Recovery and Reinvestment Act of 2009 ("ARRA"). ARRA has dedicated billions of dollars towards clean energy research and deployment. Some of Capstone's distributor's projects in Fiscal 2010 were partly funded by ARRA by providing funding to state energy programs, most notably in Pennsylvania. Members of Congress introduced legislation in calendar 2009 and 2010 that may benefit Capstone in Fiscal 2011, including energy and climate change legislation that will promote low and carbonless power generation applications. In addition, certain proposed changes to the Internal Revenue Code of 1986 may result in positive tax benefits for our end users. This proposed legislation also targets hybrid electric and natural gas-powered vehicles. Additionally, Capstone continues to engage with U.S. policymakers to develop government programs to promote low emission products. We cannot provide assurance that any such legislation will be enacted, however, or that it will benefit us if enacted.

        In California, the Self Generation Incentive Program was modified to allow natural gas-fired CHP applications to receive rebates. However, at this time, management believes that our end users would not realize any significant benefits to their capital equipment purchase plans until the second half of calendar 2010.

        Government funding can impact the rate of development of new technologies. While we continue to receive development funding, committed amounts remaining are relatively low. Competing new technologies generally receive larger incentives and development funding than do microturbines.

Sourcing and Manufacturing

        Our microturbines are designed to achieve high volume, low-cost production objectives. Our manufacturing designs include the use of conventional technology, which has been proven in high volume automotive and turbocharger production for many years. The microturbines are designed for simple assembly and testing and to facilitate automated production techniques using less-skilled labor.

        Our strategy of outsourcing the manufacturing and assembly of our nonproprietary product components allows for more attractive pricing, quick ramp-up and the use of just-in-time inventory management techniques. While the current variability in our demand volumes and resulting imprecise demand forecasting affect our ability to leverage these capabilities, management believes that we can realize economies of scale related to our product manufacturing costs as unit volume increases. We assemble and test units as well as manufacture air-bearings and certain combustion system components at our facility in Chatsworth, California. Additionally, we manufacture recuperator cores at our facility in Van Nuys, California. We have primary and secondary sources for other critical components and have evaluated our core competencies and identified additional outsourcing opportunities which we are now actively pursuing. We monitor parts subject to a single or a limited source supply to minimize factory down time due to unavailability of such parts, which could impact our ability to meet manufacturing schedules.

        Management believes our manufacturing facilities located in Chatsworth and Van Nuys, California have a combined production capacity of approximately 2,000 units per year, depending on product mix. Excluding working capital requirements, management believes we can expand our combined production capacity to approximately 4,000 units per year, depending on product mix, with approximately $10 to $15 million of capital expenditures. We have not committed to this expansion nor identified a source for its funding, if available.

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        Solar Turbines Incorporated ("Solar"), a wholly owned subsidiary of Caterpillar Inc., had been our sole supplier of recuperator cores prior to 2001. In 2000, we exercised an option to license Solar's technology, which allows us to manufacture cores ourselves. In June 2001, we started to manufacture recuperator cores. Recuperator cores using the Solar technology, which we make and sell, are subject to a per-unit royalty fee. As of March 31, 2010, cumulative royalties of $0.3 million have been paid under the terms of the licensing agreement with Solar.

        CPS will continue to manufacture the TA100 microturbines for Capstone through March 31, 2011. We have agreed to purchase for cash any remaining TA100 microturbine inventory remaining after March 31, 2011 that has not been consumed as part of the TA100 manufacturing process and is not considered in excess or obsolete, and we will obtain title to certain TA100 manufacturing equipment. On February 1, 2010, the Company and CPS also entered into an agreement pursuant to which we agreed to purchase 125 kW waste heat recovery generator systems from CPS. In exchange for certain minimum purchase requirements during a three-year period, we have exclusive rights to sell the zero-emission waste heat recovery generator for all microturbine applications and for applications 500kW or lower where the source of heat is the exhaust of a reciprocating engine used in a landfill application. We must meet specified annual sales targets in order to maintain the exclusive rights to sell the waste heat recovery generators.

Research and Development ("R&D")

        For fiscal years ended March 31, 2010, 2009 and 2008, R&D expense was $7.0 million, $8.1 million and $8.9 million and was 11%, 19% and 28% of total revenue, respectively. R&D expenses are reported net of benefits from cost-sharing programs, such as the DOE grant and the Development and License Agreement ("Development Agreement") with UTCP. Benefits from cost-sharing programs were $1.7 million, $8.1 million and $3.0 million for the years ended March 31, 2010, 2009 and 2008, respectively. Our R&D activities enabled us to become one of the first companies to develop a commercially available microturbine that operates in parallel with the grid. We were the first company to successfully demonstrate a commercially available microturbine that operates on a stand-alone basis.

        The CARB established extremely high industry standards for distributed generation by requiring emissions levels comparable to the Best Available Control Technology for large state-of-the-art central utility power plants. In March 2009, Capstone's 30 kW microturbines became even "greener" with the successful demonstration of our ultra low emissions product complying with EPA and CARB 2010 emissions requirements which reduced previous requirements for NOx by 86%, carbon monoxide (CO) by 98%, and volatile organic compounds (VOCs) by 98%. Test results showed that the microturbine removed concentrations of unburned hydrocarbons (HC) in the ambient air. The ultra low emissions performance was attained without sacrificing Capstone's signature low maintenance costs by combining ultra low emission lean premix combustion technology with a catalyst that requires no scheduled maintenance for the life of the system. This is in contrast to exhaust cleanup systems used by traditional reciprocating engine driven generation equipment that use chemicals such as ammonia or urea and need frequent adjustments to maintain proper function and air quality. Certification to this standard allows generators to be installed in most of the major air quality management districts in California without regular on-site emissions testing. To date, only microturbines and fuel cells have been certified to this new standard. Installing six 65 kW microturbines operating 24 hours a day reduces NOx emissions by approximately five tons per year which equates to the environmental impact of taking 258 cars off the road, based on EPA emissions and efficiency data for the average U.S. power plant and average passenger vehicle. Capstone enhanced its C60 Series microturbine to meet the CARB 2007 standard with co-funding from the DOE.

        Capstone microturbines are the first power generation technology to receive CARB 2008 Waste Gas Emissions certification for operation on landfill and digester gas. Capstone microturbines are capable of burning waste gases with methane contents as low as 30% which can be challenging for

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competing combustion technologies. We achieve CARB waste gas emissions requirements with our low premix combustion technology inherent to the microturbine which requires no exhaust after treatment. Certification to the new waste fuel emissions standard makes approved technologies such as the Capstone landfill and digester microturbines much easier to locate in California. Producing energy using gas from these applications avoids the need to use non-renewable resources such as coal, oil, or natural gas to produce the same amount of energy.

        Capstone released for sale its C65 Liquid Fuel configuration microturbine system. The high reliability benefits of the Capstone microturbine product make it well suited for remote power and secure power applications which often use liquid fuel. Capstone liquid fuel microturbines are able to burn a variety of fuels including kerosene, high and low sulfur diesel, and biodiesel blends.

        Capstone released versions of its C30 and C60 Series microturbine products for operation in high humidity applications. The new package provides resistance to corrosive environmental conditions typical of coastal, jungle and other high humidity installations. Previously released products for offshore manned and unmanned platforms have been well received by our oil and gas customers. The high humidity package is a further offering to many of these same customers for use at land-based oil and gas facilities.

        Our more recent significant R&D activity has been the C200 microturbine—a 200 kW, higher electrical efficiency product. Capstone worked with the DOE on its "Advanced MicroTurbine System" program and received funding for some of the early C200 development efforts. C200 beta testing demonstrated performance to design objectives making the C200 the highest electrical efficiency turbine less than 4.5 megawatts. The C200 includes the same low emissions, certification options, and flexible configuration features incorporated on our existing C30 and C60 Series products. Capstone signed an agreement with UTCP to provide cash and in-kind services to complete development and commercially launch the C200 product in September 2007. Our C200 beta testing was successfully implemented during Fiscal 2005 and the first commercial shipment was on August 28, 2008.

        Our C1000 Series product was developed based on Capstone's C200 microturbine product line. This product family can be configured into 1,000 kW, 800 kW and 600 kW solutions in a single ISO container. Benefits of the C1000 Series product include low greenhouse-gas emissions, patented air-bearing microturbine technology, ease of installation and commissioning with a single fuel and electrical connection, minimal scheduled maintenance and downtime, low noise and vibration and one of the industry's smallest modular footprints. Additional features include Capstone's remote monitoring and diagnostic capabilities and integrated utility synchronization and protection. Our C1000 product beta testing was successfully implemented during Fiscal 2009 and the first commercial shipment was on December 29, 2008.

        In September 2009, we received UL certification for our C200 Series grid-connect and stand-alone microturbine power systems as meeting the UL 2200 stationary engine generator standards and the UL 1741 utility interconnection requirements.

        The world's first boat powered with an ultra low emission Capstone C30 microturbine launched in the Netherlands on June 7, 2010. This innovative onboard energy system features a Capstone C30 diesel fueled microturbine.

        In June 2010, we received UL certification for our C1000 Series grid-connect and stand-alone microturbine power systems as meeting the UL 2200 stationary engine generator standards and the UL 1741 utility interconnection requirements.

        R&D activities have historically also focused on development of related products and applications, including gas compressors that enhance the microturbines' multi-fuel capability and integration with energy storage devices like battery packs for stand-alone applications. Current and future R&D activities are and will be in support of our focused target markets.

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        Capstone has a microturbine concept in the early stages of development, which is targeted at the needs of the Class 8 truck market (trucks or tractor- trailers with a manufacturer's listed gross vehicle weight of 33,000 pounds or more). This Inter Cooled and Recuperated ("ICR") microturbine is targeted to achieve 45% shaft efficiency while meeting 2010 EPA requirements for heavy duty diesel engines. In March 2009, we successfully demonstrated that our ICR microturbine produces emission levels that comply with the EPA and CARB 2010 requirements for heavy duty diesel engines and hybrid electric buses. Sales of heavy duty trucks and busses represent a major market opportunity, and, therefore, these applications have the potential to become a focused area for development if we can achieve the required performance and price levels.

Protecting our Intellectual Property Rights and Patents

        We rely on a combination of patent, trade secret, copyright and trademark law and nondisclosure agreements to establish and protect our intellectual property rights in our products. In this regard, we have obtained 111 U.S. and 35 international patents (in certain cases covering the same technology in multiple jurisdictions). The patents we have obtained will expire between 2014 and 2027. These numbers include 24 U.S. patents and 35 international patents that were acquired from CPS.

        Management believes that a policy of protecting intellectual property is an important component of our strategy of being the leader in microturbine system technology and will provide us with a long-term competitive advantage. In addition, we implement security procedures at our plants and facilities and have confidentiality agreements with our suppliers, distributors, employees and certain visitors to our facilities.

Organization and Employees

        We were organized in 1988. On June 22, 2000, we reincorporated as a Delaware corporation.

        As of March 31, 2010, we had 182 employees. No employees are covered by collective bargaining arrangements. We consider relations with our employees to be good.

Available Information

        This annual report on Form 10-K ("Annual Report"), as well as our quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to section 13(a) or 15(d) of the Exchange Act are made available free of charge on the Company's Internet website (http://www.capstoneturbine.com) as soon as reasonably practicable after such materials are electronically filed with or furnished to the Securities and Exchange Commission ("SEC").

Item 1A.    Risk Factors.

        This document contains certain forward-looking statements (as such term is defined in Section 27A of the Securities Act of 1933, as amended (the "Securities Act") and Section 21E of the Securities Exchange Act of 1934, as amended (the "Exchange Act") pertaining to, among other things, our results of operations, profits and losses, R&D activities, sales expectations, our ability to develop markets for our products, sources for parts, federal, state and local government regulations, general business, industry and economic conditions applicable to us, the reliability of our products and their need for maintenance, our ability to be cost-competitive and to outperform competition, customer satisfaction, the value of using our products, our ability to achieve economies of scale, market advantage, return on investments, functionality of our products, our microturbine technology, the utilization of our products, our creation of market advantages, competition, the introduction of new technologies, our production capacity, expiration of patents, protection of intellectual property, the adequacy of our facilities, the impact of pending litigation, dividends, business strategy, product development, critical accounting policies, capital resources, capital expenditures, liquidity, amortization

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expense of intangibles, cost of warranties, stock-based compensation, our stockholders rights plan, purchase and lease commitments, current liabilities, the transaction with Calnetix Power Solutions, Inc., recently issued accounting standards, market risk and interest rate sensitivity. These statements are based largely on our current expectations, estimates and forecasts and are subject to a number of risks and uncertainties. Actual results could differ materially from those anticipated by these forward-looking statements. Factors that can cause actual results to differ materially include, but are not limited to, those discussed below. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. The following factors should be considered in addition to the other information contained herein in evaluating Capstone and its business. We assume no obligation to update any of the forward-looking statements after the filing of this Annual Report to conform such statements to actual results or to changes in our expectations, except as may be required by law.

        The following are risk factors that could affect our business, financial condition, results of operations, and cash flows. These risk factors should be considered in connection with evaluating the forward-looking statements contained in this Annual Report because these factors could cause the actual results and conditions to differ materially from those projected in forward- looking statements. Before you invest in our publicly traded securities, you should know that making such an investment involves some risks, including the risks described below. Additional risks of which we may not be aware or that we currently believe are immaterial may also impair our business operations or our stock price. If any of the risks actually occur, our business, financial condition, results of operations or cash flow could be negatively affected. In that case, the trading price of our common stock could decline, and you may lose all or part of your investment. In assessing these risks, investors should also refer to the other information contained or incorporated by reference in this Annual Report, our quarterly reports on Form 10-Q and other documents filed by us from time to time.

Our operating history is characterized by net losses. We anticipate further losses and we may never become profitable.

        Since inception, we have incurred annual operating losses. We expect this trend to continue until such time that we can sell a sufficient number of units and achieve a cost structure to become profitable. Our business is such that we have relatively few customers and limited repeat business. As a result, we may not maintain or increase revenue. We may not have adequate cash resources to reach the point of profitability, and we may never become profitable. Even if we do achieve profitability, we may be unable to increase our sales and sustain or increase our profitability in the future.

We may be unable to fund our future operating requirements, which could force us to curtail our operations.

        To the extent that the funds we now have on hand are insufficient to fund our future operating requirements, we would need to raise additional funds, through further public or private equity or debt financings depending upon prevailing market conditions. These financings may not be available, or if available, may be on terms that are not favorable to us and could result in dilution to our stockholders and reduction of the trading price of our stock. The state of worldwide capital markets could also impede our ability to raise additional capital on favorable terms or at all. If adequate capital were not available to us, we likely would be required to significantly curtail our operations or possibly even cease our operations.

        We maintain two Credit and Security Agreements with Wells Fargo Bank, National Association, or Wells Fargo, that provide us with a line of credit of up to $10 million in the aggregate. At March 31, 2010, we had $7.6 million outstanding under this line of credit. Under this credit facility, we are required to satisfy specified financial and restrictive covenants. Failure to comply with these covenants could cause an event of default which, if not cured or waived, could require us to repay substantial indebtedness immediately. At several times during the Fiscal 2010 and as of March 31, 2010, we have been in noncompliance with certain covenants under the credit facility. In connection with each event

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of noncompliance, Wells Fargo has waived the event of default and, on several occasions, we have amended the credit facility agreements in response to the default and waiver. For more information, see the section below entitled "Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources." If we had not obtained these waivers, or if we are ever again in noncompliance, we may not be able to draw additional funds under the credit facility. In addition, we have pledged our accounts receivables, inventories, equipment, patents and other assets as collateral under the credit facility agreements, which would be subject to seizure by Wells Fargo if we were in default and unable to repay the indebtedness. As a condition of the recent amended Agreements, we have restricted $5.0 million of cash as additional security for the credit facility. Wells Fargo also has the option to terminate the credit facility or accelerate the indebtedness during a period of noncompliance.

        Our obligations under the credit facility could have important consequences, including the following:

•

We may have difficulty obtaining additional financing at favorable interest rates to meet our requirements for operations, capital expenditures, general corporate or other purposes.



•

We will be required to dedicate a substantial portion of our cash flow to the payment of principal and interest on indebtedness, which will reduce the amount of funds available for operations, capital expenditures and future acquisitions.



•

We may be required to pay our indebtedness immediately if we default on any of the numerous financial or other restrictive covenants contained in the debt agreements. It is not certain whether we will have, or will be able to obtain, sufficient funds to make these accelerated payments. If any outstanding indebtedness under the credit facility is accelerated, our assets may not be sufficient to repay such indebtedness..

If we are unable to either substantially improve our operating results or obtain additional financing, we may be unable to continue as a going concern.

        Should we be unable to execute our plans to build sales and margins while controlling costs and obtain additional financing, we may be unable to continue as a going concern. In particular, we must generate positive cash flow from operations and net income and otherwise improve our results of operations substantially. Our available cash and proceeds from future financings, if any, that we may be able to obtain, may not be sufficient to fund our operating expenses, capital expenditures and other cash requirements. As a result, this would affect our ability to continue as a going concern. These events and circumstances could have a material adverse effect on our ability to raise additional capital and on the market value of our common stock. Moreover, should we experience a cash shortage that requires us to curtail or cease our operations, or should we be unable to continue as a going concern, you could lose all or part of your investments in our securities.

Impairment charges on our long-lived assets, including intangible assets with finite lives would adversely affect our financial position and results of operations.

        We evaluate the carrying value of long-lived assets, including intangible assets with finite lives, for impairment whenever events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. To determine whether impairment has occurred, we compare the undiscounted cash flows of the long-lived asset with its carrying value. The estimation of future cash flows requires significant estimates of factors that include future sales growth, gross margin performance, including our estimates of reductions in our direct material costs, and reductions in operating expenses. If our sales growth, gross margin performance or other estimated operating results are not achieved at or above our forecasted level, or inflation exceeds our forecast, the carrying value of our asset groups may prove to be unrecoverable and we may incur impairment charges in the future. In addition, significant

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and unanticipated changes in circumstances, such as significant adverse changes in business climate, unanticipated competition, loss of key customers or changes in technology or markets, could require a charge for impairment that can materially and adversely affect our reported net loss and our stockholders' equity.

A sustainable market for microturbines may never develop or may take longer to develop than we anticipate which would adversely affect our results of operations.

        Our products represent an emerging market, and we do not know whether our targeted customers will accept our technology or will purchase our products in sufficient quantities to allow our business to grow. To succeed, demand for our products must increase significantly in existing markets, and there must be strong demand for products that we introduce in the future. If a sustainable market fails to develop or develops more slowly than we anticipate, we may be unable to recover the losses we have incurred to develop our products, we may have further impairment of assets, and we may be unable to meet our operational expenses. The development of a sustainable market for our systems may be hindered by many factors, including some that are out of our control. Examples include:

•

consumer reluctance to try a new product;



•

regulatory requirements;



•

the cost competitiveness of our microturbines;



•

costs associated with the installation and commissioning of our microturbines;



•

maintenance and repair costs associated with our microturbines;



•

the future costs and availability of fuels used by our microturbines;



•

economic downturns and reduction in capital spending;



•

consumer perceptions of our microturbines' safety and quality;



•

the emergence of newer, more competitive technologies and products; and



•

decrease in domestic and international incentives.

Our operating results are dependent, in large part, upon the successful commercialization of our products. Failure to produce our products as scheduled and budgeted would materially and adversely affect our business and financial condition.

        We cannot be certain that we will deliver ordered products in a timely manner. Any reliability or quality issues that may arise with our products could prevent or delay scheduled deliveries. Any such delays or costs could significantly impact our business, financial condition and operating results.

We may not be able to effectively manage our growth, expand our production capabilities or improve our operational, financial and management information systems, which would impair our results of operations.

        If we are successful in executing our business plan, we will experience growth in our business that could place a significant strain on our business operations, management and other resources. Our ability to manage our growth will require us to expand our production capabilities, continue to improve our operational, financial and management information systems, and to motivate and effectively manage our employees. We cannot provide assurance that our systems, procedures and controls or financial resources will be adequate, or that our management will keep pace with this growth. We cannot provide assurance that our management will be able to manage this growth effectively.

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The current global financial crisis may have an impact on our business and financial condition, including some effects we may not be able to predict.

        The continued credit crisis could prevent our customers from purchasing our products or delay their purchases, which would adversely affect our business, financial condition and results of operations. In addition, our ability to access the capital markets may be severely restricted or made very expensive at a time when we need, or would like to do so, which could have a material adverse impact on our liquidity and financial resources. Certain industries in which our customers do business and certain geographic areas have been and could continue to be adversely affected by the recession in economic activity.

Our suppliers may not supply us with a sufficient amount of components or components of adequate quality or they may provide components at significantly increased prices, and, therefore, we may not be able to produce our products.

        Some of our components are currently available only from a single source or limited sources. We may experience delays in production if we fail to identify alternative suppliers, or if any parts supply is interrupted, each of which could materially adversely affect our business and operations. In order to reduce manufacturing lead times and ensure adequate component supply, we enter into agreements with certain suppliers that allow them to procure inventories based upon criteria defined by us. If we fail to anticipate customer demand properly, an oversupply of parts could result in excess or obsolete inventories, which could adversely affect our business. Our inability to meet volume commitments with suppliers could affect the availability or pricing of our parts and components. A reduction or interruption in supply, a significant increase in price of one or more components or a decrease in demand of products could materially adversely affect our business and operations and could materially damage our customer relationships. Financial problems of suppliers on whom we rely could limit our supply of components or increase our costs. Also, we cannot guarantee that any of the parts or components that we purchase will be of adequate quality or that the prices we pay for the parts or components will not increase. Inadequate quality of products from suppliers could interrupt our ability to supply quality products to our customers in a timely manner. Additionally, defects in materials or products supplied by our suppliers that are not identified before our products are placed in service by our customers could result in higher warranty costs and damage to our reputation. We also outsource certain of our components internationally and expect to increase international outsourcing of components. As a result of outsourcing internationally, we may be subject to delays in delivery due to the timing or regulations associated with the import/export process, delays in transportation or regional instability.

Product quality expectations may not be met, causing slower market acceptance or warranty cost exposure.

        In order to achieve our goal of improving the quality and lowering the total costs of ownership of our products, we may require engineering changes. Such improvement initiatives may render existing inventories obsolete or excessive. Despite our continuous quality improvement initiatives, we may not meet customer expectations. Any significant quality issues with our products could have a material adverse effect on our rate of product adoption, results of operations, financial condition and cash flow. Moreover, as we develop new configurations for our microturbines and as our customers place existing configurations in commercial use, our products may perform below expectations. Any significant performance below expectations could adversely affect our operating results, financial condition and cash flow and affect the marketability of our products.

        We sell our products with warranties. There can be no assurance that the provision for estimated product warranty will be sufficient to cover our warranty expenses in the future. We cannot ensure that our efforts to reduce our risk through warranty disclaimers will effectively limit our liability. Any significant incurrence of warranty expense in excess of estimates could have a material adverse effect

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on our operating results, financial condition and cash flow. Further, we have at times undertaken programs to enhance the performance of units previously sold. These enhancements have at times been provided at no cost or below our cost. If we choose to offer such programs again in the future, such actions could result in significant costs.

We operate in a highly competitive market among competitors who have significantly greater resources than we have and we may not be able to compete effectively.

        Capstone microturbines compete with several technologies, including reciprocating engines, fuel cells and solar power. Competing technologies may receive certain benefits, like governmental subsidies or promotion, or be able to offer consumer rebates or other incentives that we cannot receive or offer to the same extent. This could enhance our competitors' abilities to fund research, penetrate markets or increase sales. We also compete with other manufacturers of microturbines.

        Our competitors include several well-known companies with histories of providing power solutions. They have substantially greater resources than we have and have established worldwide presence. Because of greater resources, some of our competitors may be able to adapt more quickly to new or emerging technologies and changes in customer requirements, to devote greater resources to the promotion and sale of their products than we can or lobby for governmental regulations and policies to create competitive advantages vis-à-vis our products. We believe that developing and maintaining a competitive advantage will require continued investment by us in product development and quality, as well as attention to product performance, our product prices, our conformance to industry standards, manufacturing capability and sales and marketing. In addition, current and potential competitors have established or may in the future establish collaborative relationships among themselves or with third parties, including third parties with whom we have business relationships. Accordingly, new competitors or alliances may emerge and rapidly acquire significant market share.

        Overall, the market for our products is highly competitive and is changing rapidly. We believe that the primary competitive factors affecting the market for our products, including some that are outside of our control, include:

•

name recognition, historical performance and market power of our competitors;



•

product quality and performance;



•

operating efficiency;



•

product price;



•

availability, price and compatibility of fuel;



•

development of new products and features; and



•

emissions levels.

        There is no assurance that we will be able to successfully compete against either current or potential competitors or that competition will not have a material adverse effect on our business, operating results, financial condition and cash flow.

If we do not effectively implement our sales, marketing and service plans, our sales will not grow and our results of operations will suffer.

        Our sales and marketing efforts may not achieve intended results and, therefore, may not generate the revenue we anticipate. As a result of our corporate strategies, we have decided to focus our resources on selected vertical markets. We may change our focus to other markets or applications in the future. There can be no assurance that our focus or our near term plans will be successful. If we

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are not able to successfully address markets for our products, we may not be able to grow our business, compete effectively or achieve profitability.

        We offer direct sales and service in selected markets. We do not have extensive experience in providing direct sales and service and may not be successful in executing this strategy. In addition, we may lose existing distributors or service providers or we may have more difficulty attracting new distributors and service providers as a result of this strategy. Further, we may incur new types of obligations, such as extended service obligations, that could result in costs that exceed the related revenue. We may encounter new transaction types through providing direct sales and service and these transactions may require changes to our historic business practices. For example, an arrangement with a third party leasing company may require us to provide a residual value guarantee, which is not consistent with our past operating practice.

        Also, as we expand in international markets, customers may have difficulty or be unable to integrate our products into their existing systems or may have difficulty complying with foreign regulatory and commercial requirements. As a result, our products may require redesign. Any redesign of the product may delay sales or cause quality issues. In addition, we may be subject to a variety of other risks associated with international business, including import/export restrictions, fluctuations in currency exchange rates and global economic or political instability. In that regard, BPC, which accounted for approximately 20% of our net accounts receivable as of March 31, 2010 and approximately 14% of our revenue for Fiscal 2010, is a privately owned company located in Russia, and we are, therefore, particularly susceptible to risks associated with doing business in that country.

We cannot be certain of the future effectiveness of our internal controls over financial reporting or the impact thereof on our operations or the market price of our common stock.

        Pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, we are required to include in our Annual Reports on Form 10-K our assessment of the effectiveness of our internal controls over financial reporting. We cannot be certain that our internal controls over financial reporting will remain effective or that future material changes to our internal controls will be effective. If we cannot adequately maintain the effectiveness of our internal controls over financial reporting, we might be subject to sanctions or investigation by regulatory authorities, such as the SEC. Any such action could adversely affect our financial results and the market price of our common stock or warrants.

We may not be able to retain or develop relationships with OEMs or distributors in our targeted markets, in which case our sales would not increase as expected.

        In order to serve certain of our targeted markets, we believe that we must ally ourselves with companies that have particular expertise or better access to those markets. We believe that retaining or developing relationships with strong OEMs (which to date have typically resold our products under their own brands or packaged our products with other products as part of an integrated unit) or distributors in these targeted markets can improve the rate of adoption as well as reduce the direct financial burden of introducing a new technology and creating a new market. Because of OEMs' and distributors' relationships in their respective markets, the loss of an OEM or distributor could adversely impact the ability to penetrate our target markets. We offer our OEMs and distributors stated discounts from list price for the products they purchase. In the future, to attract and retain OEMs and distributors we may provide volume price discounts or otherwise incur significant costs that may reduce the potential revenues from these relationships. We may not be able to retain or develop appropriate OEMs and distributors on a timely basis, and we cannot provide assurance that the OEMs and distributors will focus adequate resources on selling our products or will be successful in selling them. In addition, some of the relationships may require that we grant exclusive distribution rights in defined territories. These exclusive distribution arrangements could result in our being unable to enter into other arrangements at a time when the OEM or distributor with whom we form a relationship is not

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successful in selling our products or has reduced its commitment to market our products. We cannot provide assurance that we will be able to negotiate collaborative relationships on favorable terms or at all. Our inability to have appropriate distribution in our target markets may adversely affect our financial condition, results of operations and cash flow.

Activities necessary to integrate the acquisition of the microturbine business of CPS and any future acquisitions may result in costs in excess of current expectations or be less successful than anticipated.

        We recently completed the acquisition of certain assets relating to the microturbine business of CPS, and we may acquire other businesses in the future. The success of these transactions will depend on, among other things, our ability to develop productive relationships with the corresponding distributors and to integrate assets and personnel, if any, acquired in these transactions and to apply our internal controls processes to these acquired businesses. The integration of any acquired businesses or significant assets may require significant attention from our management, and the diversion of management's attention and resources could have a material adverse effect on our ability to manage our business. Furthermore, we may not realize the degree or timing of benefits we anticipated when we first enter into these transactions. If actual integration costs are higher than amounts assumed, if we are unable to integrate the assets and personnel acquired in an acquisition as anticipated, or if we are unable to fully benefit from anticipated synergies, our business, financial condition, results of operations, and cash flows could be materially adversely affected.

Loss of a significant customer could have a material adverse effect on our results of operations.

        Aquatec and BPC each accounted for approximately 14% of our revenue for the fiscal year ended March 31, 2010. As of March 31, 2010, Aquatec and BPC represented 7% and 20% of net accounts receivable, respectively. Loss of Aquatec, BPC or any other significant customers could adversely affect our results of operations.

We may not be able to develop sufficiently trained applications engineering, installation and service support to serve our targeted markets.

        Our ability to identify and develop business relationships with companies who can provide quality, cost-effective application engineering, installation and service can significantly affect our success. The application engineering and proper installation of our microturbines, as well as proper maintenance and service, are critical to the performance of the units. Additionally, we need to reduce the total installed cost of our microturbines to enhance market opportunities. Our inability to improve the quality of applications, installation and service while reducing associated costs could affect the marketability of our products.

Changes in our product components may require us to replace parts held at distributors and ASCs.

        We have entered into agreements with some of our distributors and ASCs requiring that if we render parts obsolete in inventories they own and hold in support of their obligations to serve fielded microturbines, we are required to replace the affected stock at no cost to the distributors or ASCs. It is possible that future changes in our product technology could involve costs that have a material adverse effect on our results of operations, cash flow or financial position.

We operate in a highly regulated business environment, and changes in regulation could impose significant costs on us or make our products less economical, thereby affecting demand for our microturbines.

        Our products are subject to federal, state, local and foreign laws and regulations, governing, among other things, emissions and occupational health and safety. Regulatory agencies may impose special requirements for the implementation and operation of our products or that may significantly affect or

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even eliminate some of our target markets. We may incur material costs or liabilities in complying with government regulations. In addition, potentially significant expenditures could be required in order to comply with evolving environmental and health and safety laws, regulations and requirements that may be adopted or imposed in the future. Furthermore, our potential utility customers must comply with numerous laws and regulations. The deregulation of the utility industry may also create challenges for our marketing efforts. For example, as part of electric utility deregulation, federal, state and local governmental authorities may impose transitional charges or exit fees, which would make it less economical for some potential customers to switch to our products. We can provide no assurances that we will be able to obtain these approvals and changes in a timely manner, or at all. Non-compliance with applicable regulations could have a material adverse effect on our operating results.

        The market for electricity and generation products is heavily influenced by federal and state government regulations and policies. The deregulation and restructuring of the electric industry in the United States and elsewhere may cause rule changes that may reduce or eliminate some of the advantages of such deregulation and restructuring. We cannot determine how any deregulation or restructuring of the electric utility industry may ultimately affect the market for our microturbines. Changes in regulatory standards or policies could reduce the level of investment in the research and development of alternative power sources, including microturbines. Any reduction or termination of such programs could increase the cost to our potential customers, making our systems less desirable, and thereby adversely affect our revenue and other operating results.

Utility companies or governmental entities could place barriers to our entry into the marketplace, and we may not be able to effectively sell our products.

        Utility companies or governmental entities could place barriers on the installation of our products or the interconnection of the products with the electric grid. Further, they may charge additional fees to customers who install on-site generation or have the capacity to use power from the grid for back-up or standby purposes. These types of restrictions, fees or charges could hamper the ability to install or effectively use our products or increase the cost to our potential customers for using our systems. This could make our systems less desirable, thereby adversely affecting our revenue and other operating results. In addition, utility rate reductions can make our products less competitive which would have a material adverse effect on our operations. The cost of electric power generation bears a close relationship to natural gas and other fuels. However, changes to electric utility tariffs often require lengthy regulatory approval and include a mix of fuel types as well as customer categories. Potential customers may perceive the resulting swings in natural gas and electric pricing as an increased risk of investing in on-site generation.

We depend upon the development of new products and enhancements of existing products.

        Our operating results depend on our ability to develop and introduce new products, or enhance existing products and to reduce the costs to produce our products. The success of our products is dependent on several factors, including proper product definition, product cost, timely completion and introduction of the products, differentiation of products from those of our competitors, meeting changing customer requirements, emerging industry standards and market acceptance of these products. The development of new, technologically advanced products and enhancements is a complex and uncertain process requiring high levels of innovation, as well as the accurate anticipation of technological and market trends. There can be no assurance that we will successfully identify new product opportunities, develop and bring new or enhanced products to market in a timely manner, successfully lower costs and achieve market acceptance of our products, or that products and technologies developed by others will not render our products or technologies obsolete or noncompetitive.

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Operational restructuring may result in asset impairment or other unanticipated charges.

        As a result of our corporate strategies, we have identified opportunities to outsource to third-party suppliers certain functions which we currently perform. We believe outsourcing can reduce product costs, improve product quality or increase operating efficiency. These actions may not yield the expected results, and outsourcing may result in production delays or lower quality products. Transitioning to outsourcing may cause certain of our affected employees to leave before the outsourcing is complete. This could result in a lack of the experienced in-house talent necessary to successfully implement the outsourcing. Further, depending on the nature of operations outsourced and the structure of agreements we reach with suppliers to perform these functions, we may experience impairment in the value of manufacturing assets related to the outsourced functions or other unanticipated charges, which could have a material adverse effect on our operating results.

We may not achieve production cost reductions necessary to competitively price our products, which would adversely affect our sales.

        We believe that we will need to reduce the unit production cost of our products over time to maintain our ability to offer competitively priced products. Our ability to achieve cost reductions will depend on our ability to develop low cost design enhancements, to obtain necessary tooling and favorable supplier contracts and to increase sales volumes so we can achieve economies of scale. We cannot provide assurance that we will be able to achieve any such production cost reductions. Our failure to achieve such cost reductions could have a material adverse effect on our business and results of operations.

Commodity market factors impact our costs and availability of materials.

        Our products contain a number of commodity materials, from metals, which includes steel, special high temperature alloys, copper, nickel and molybdenum, to computer components. The availability of these commodities could impact our ability to acquire the materials necessary to meet our requirements. The cost of metals has historically fluctuated. The pricing could impact the costs to manufacture our products. If we are not able to acquire commodity materials at prices and on terms satisfactory to us or at all, our operating results may be materially adversely affected.

Our products involve a lengthy sales cycle and we may not anticipate sales levels appropriately, which could impair our results of operations.

        The sale of our products typically involves a significant commitment of capital by customers, with the attendant delays frequently associated with large capital expenditures. For these and other reasons, the sales cycle associated with our products is typically lengthy and subject to a number of significant risks over which we have little or no control. We expect to plan our production and inventory levels based on internal forecasts of customer demand, which is highly unpredictable and can fluctuate substantially. If sales in any period fall significantly below anticipated levels, our financial condition, results of operations and cash flow would suffer. If demand in any period increases well above anticipated levels, we may have difficulties in responding, incur greater costs to respond, or be unable to fulfill the demand in sufficient time to retain the order, which would negatively impact our operations. In addition, our operating expenses are based on anticipated sales levels, and a high percentage of our expenses are generally fixed in the short term. As a result of these factors, a small fluctuation in timing of sales can cause operating results to vary materially from period to period.

Potential intellectual property, stockholder or other litigation may adversely impact our business.

        We may face litigation relating to intellectual property matters, labor matters, product liability, or other matters. We are a party to stockholder lawsuits alleging violations of securities laws in connection

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with our June 2000 initial public offering and November 2000 secondary offering described under "Legal Proceedings" in this Annual Report. An adverse judgment could negatively impact our financial position and results of operations, the trading price of our common stock and our ability to obtain future financing on favorable terms or at all. Any litigation could be costly, divert management attention or result in increased costs of doing business.

Our success depends in significant part upon the continuing service of management and key employees.

        Our success depends in significant part upon the continuing service of our executive officers, senior management and sales and technical personnel. The failure of our personnel to execute our strategy or our failure to retain management and personnel could have a material adverse effect on our business. Our success will be dependent on our continued ability to attract, retain and motivate highly skilled employees. There can be no assurance that we can do so.

        Our internal control systems rely on people trained in the execution of the controls. Loss of these people or our inability to replace them with similarly skilled and trained individuals or new processes in a timely manner could adversely impact our internal control mechanisms.

Our operations are vulnerable to interruption by fire, earthquake and other events beyond our control.

        Our operations are vulnerable to interruption by fire, earthquake and other events beyond our control. Our executive offices and manufacturing facilities are located in southern California. Because the southern California area is located in an earthquake-sensitive area, we are particularly susceptible to the risk of damage to, or total destruction of, our facilities in southern California and the surrounding transportation infrastructure, which could affect our ability to make and transport our products. We do not maintain earthquake insurance coverage for personal property or resulting business interruption. If an earthquake, fire or other natural disaster occurs at or near our facilities, our business, financial condition, operating results and cash flow could be materially adversely affected.

The market price of our common stock has been and may continue to be highly volatile and you could lose all or part of your investment in our securities.

        An investment in our securities is risky, and stockholders could lose their investment in our securities or suffer significant losses and wide fluctuations in the market value of their investment. The market price of our common stock is highly volatile and is likely to continue to be highly volatile. Given the continued uncertainty surrounding many variables that may affect our business and the industry in which we operate, our ability to foresee results for future periods is limited. This variability could affect our operating results and thereby adversely affect our stock price. Many factors that contribute to this volatility are beyond our control and may cause the market price of our common stock to change, regardless of our operating performance. Factors that could cause fluctuation in our stock price may include, among other things:

•

actual or anticipated variations in quarterly operating results;



•

market sentiment toward alternative energy stocks in general or toward Capstone;



•

changes in financial estimates or recommendations by securities analysts;



•

conditions or trends in our industry or the overall economy;



•

loss of one or more of our significant customers;



•

errors, omissions or failures by third parties in meeting commitments to us;



•

changes in the market valuations or earnings of our competitors or other technology companies;



•

the trading of options on our common stock;

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•

announcements by us or our competitors of significant acquisitions, strategic partnerships, divestitures, joint ventures or other strategic initiatives;



•

announcements of significant market events, such as power outages, regulatory changes or technology changes;



•

changes in the estimation of the future size and growth rate of our market;



•

future equity financings;



•

the failure to produce our products on a timely basis in accordance with customer expectations;



•

the inability to obtain necessary components on time and at a reasonable cost;



•

litigation or disputes with customers or business partners;



•

capital commitments;



•

additions or departures of key personnel;



•

sales or purchases of our common stock;



•

the trading volume of our common stock;



•

developments relating to litigation or governmental investigations; and



•

decreases in oil, natural gas and electricity prices.

        In addition, the stock market in general, and the NASDAQ Global Market and the market for technology companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of particular companies affected. The market prices of securities of technology companies and companies servicing the technology industries have been particularly volatile. These broad market and industry factors may cause a material decline in the market price of our common stock, regardless of our operating performance. In the past, following periods of volatility in the market price of a company's securities, securities class- action litigation has often been instituted against that company. We are currently subject to litigation relating to our initial public offering and a subsequent common stock offering as described under "Legal Proceedings" in this Annual Report. This type of litigation, regardless of whether we prevail on the underlying claim, could result in substantial costs and a diversion of management's attention and resources, which could materially harm our financial condition, results of operations and cash flow.

Provisions in our certificate of incorporation, bylaws and our stockholder rights plan, as well as Delaware law, may discourage, delay or prevent a merger or acquisition at a premium price.

        Provisions of our second amended and restated certificate of incorporation, amended and restated bylaws and our stockholder rights plan, as well as provisions of the General Corporation Law of the State of Delaware, could discourage, delay or prevent unsolicited proposals to merge with or acquire us, even though such proposals may be at a premium price or otherwise beneficial to you. These provisions include our board's authorization to issue shares of preferred stock, on terms the board determines in its discretion, without stockholder approval, and the following provisions of Delaware law that restrict many business combinations.

        We are subject to the provisions of Section 203 of the General Corporation Law of the State of Delaware, which could prevent us from engaging in a business combination with a 15% or greater stockholder for a period of three years from the date it acquired such status unless appropriate board or stockholder approvals are obtained.

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        Our board of directors has adopted a stockholder rights plan, pursuant to which one preferred stock purchase right has been issued for each share of our common stock authorized and outstanding. Until the occurrence of certain prescribed events, the rights are not exercisable and are transferable along with, and only with, each share of our common stock and are evidenced by the common stock certificates. One preferred stock purchase right will also be issued with each share of our common stock we issue in the future until the rights plan expires or is terminated or we redeem or exchange the rights for other property in accordance with the terms of the rights plan or at such time, if any, as the rights separate from each share of our common stock and become exercisable. Each share of Series A Junior Participating Preferred Stock will be entitled to receive, when, as and if declared by our board of directors out of funds legally available for the purpose, dividends payable in cash in an amount per share (rounded to the nearest cent) equal to 100 times the aggregate per share amount of all dividends or other distributions, including non-cash dividends (payable in kind), declared on our common stock other than a dividend payable in shares of common stock or a subdivision of the outstanding shares of common stock. The rights plan prohibits the issuance of additional rights after the rights separate from our common stock. The rights plan is intended to protect our stockholders in the event of an unfair or coercive offer to acquire us. However, the existence of the rights plan may discourage, delay or prevent a merger or acquisition of us that is not supported by our board of directors.

Item 1B.    Unresolved Staff Comments.

        None.

Item 2.    Properties.

        Our principal corporate offices, administrative, sales and marketing, R&D and support facilities consist of approximately 98,000 square feet of leased office space, warehouse space and assembly and test space located at 21211 Nordhoff Street in Chatsworth, California. Our lease for those premises expires in July 2014, and we have two five-year options to extend the term of this lease. We also lease an approximately 79,000 square foot facility at 16640 Stagg Street in nearby Van Nuys, California as an engineering test and manufacturing facility for our recuperator cores. This lease will expire in December 2012, and we have one five-year option to extend this lease.

        Management believes our facilities are adequate for our current needs.

Item 3.    Legal Proceedings.

        In December 2001, a purported stockholder class action lawsuit was filed in the United States District Court for the Southern District of New York (the "District Court") against the Company, two of its then officers, and the underwriters of our initial public offering. The suit purports to be a class action filed on behalf of purchasers of our common stock during the period from June 28, 2000 to December 6, 2000. An amended complaint was filed on April 19, 2002. The plaintiffs allege that the prospectuses for our June 28, 2000 initial public offering and November 16, 2000 secondary offering were false and misleading in violation of the applicable securities laws because the prospectuses failed to disclose the underwriter defendants' alleged agreement to allocate stock in these offerings to certain investors in exchange for excessive and undisclosed commissions and agreements to make additional purchases of stock in the aftermarket at pre-determined prices. Similar complaints have been filed against hundreds of other issuers that have had initial public offerings since 1998; the complaints have been consolidated into an action captioned In re Initial Public Offering Securities Litigation, No. 21 MC 92. On October 9, 2002, the plaintiffs dismissed, without prejudice, the claims against the named officers and directors in the action against the Company. The District Court directed that the litigation proceed within a number of "focus cases" and on October 13, 2004, the District Court certified the focus cases as class actions. Our case is not one of these focus cases. The underwriter defendants appealed that ruling, and on December 5, 2006, the Court of Appeals for the Second Circuit reversed

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the District Court's class certification decision. On August 14, 2007, the plaintiffs filed their second consolidated amended complaints against the six focus cases and on September 27, 2007, again moved for class certification. On November 12, 2007, certain of the defendants in the focus cases moved to dismiss the second consolidated amended class action complaints. On March 26, 2008, the District Court denied the motions to dismiss except as to Section 11 claims raised by those plaintiffs who sold their securities for a price in excess of the initial offering price and those who purchased outside the previously certified class period. The motion for class certification was withdrawn without prejudice on October 10, 2008. On April 2, 2009, a stipulation and agreement of settlement between the plaintiffs, issuer defendants and underwriter defendants was submitted to the District Court for preliminary approval. The District Court granted the plaintiffs' motion for preliminary approval and preliminarily certified the settlement classes on June 10, 2009. The settlement "fairness" hearing was held on September 10, 2009. On October 6, 2009, the District Court entered an opinion granting final approval to the settlement and directing that the Clerk of the District Court close these actions. Notices of appeal of the opinion granting final approval have been filed. Because of the inherent uncertainties of litigation and because the settlement remains subject to appeal, the ultimate outcome of the matter is uncertain, and management believes that the outcome of this litigation will not have a material adverse impact on the consolidated financial position and results of operations.

        On October 9, 2007, Vanessa Simmonds, a purported stockholder of the Company, filed suit in the U.S. District Court for the Western District of Washington(the "Washington District Court") against The Goldman Sachs Group, Inc., Merrill Lynch & Co., Inc., and Morgan Stanley, the lead underwriters of our initial public offering in June 1999, and our secondary offering of common stock in November 2000, alleging violations of Section 16(b) of the Securities Exchange Act of 1934, 15 U.S.C. § 78p(b). The complaint sought to recover from the lead underwriters any "short-swing profits" obtained by them in violation of Section 16(b). The suit names the Company as a nominal defendant, contained no claims against the Company, and sought no relief from the Company. Simmonds filed an Amended Complaint on February 27, 2008 (the "Amended Complaint"), naming as defendants Goldman Sachs & Co. and Merrill Lynch Pierce, Fenner & Smith Inc. and again naming Morgan Stanley. The Goldman Sachs Group, Inc. and Merrill Lynch & Co., Inc. were no longer named as defendants. The Amended Complaint asserted substantially similar claims as those set forth in the initial complaint. On July 25, 2008, the Company joined with 29 other issuers to file the Issuer Defendants' Joint Motion to Dismiss. Simmonds filed her opposition to this motion on September 8, 2008, and the Company and the other Issuer Defendants filed a Reply in Support of Their Joint Motion to Dismiss on October 23, 2008. On March 12, 2009, the Washington District Court granted the Issuer Defendants' Joint Motion to Dismiss, dismissing the complaint without prejudice on the grounds that Simmonds had failed to make an adequate demand on the Company prior to filing her complaint. In its order, the Washington District Court stated that it would not permit Simmonds to amend her demand letters while pursuing her claims in the litigation. Because the Washington District Court dismissed the case on the grounds that it lacked subject matter jurisdiction, it did not specifically reach the issue of whether Simmonds' claims were barred by the applicable statute of limitations. However, the Washington District Court also granted the Underwriters' Joint Motion to Dismiss with respect to cases involving non-moving issuers, holding that the cases were barred by the applicable statute of limitations because the issuers' stockholders had notice of the potential claims more than five years prior to filing suit. Simmonds filed a Notice of Appeal on April 10, 2009. The underwriters subsequently filed a Notice of Cross-Appeal, arguing that the dismissal of the claims involving the moving issuers should have been with prejudice because the claims were untimely under the applicable statute of limitations. Simmonds filed her opening brief on appeal on August 26, 2009. On October 2, 2009, the Company and other Issuer Defendants filed a joint response brief, and the underwriters filed a brief in support of their cross-appeal. Simmonds' reply brief and opposition to the cross-appeal were filed on November 2, 2009 and the underwriters' reply brief in support of their cross-appeals were filed on November 17, 2009.

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Management believes that the outcome of this litigation will not have a material adverse impact on our consolidated financial position and results of operations.

        From time to time, the Company may become subject to additional legal proceedings, claims and litigation arising in the ordinary course of business. Other than the matters discussed above, we are not a party to any other material legal proceedings, nor are we aware of any other pending or threatened litigation that would have a material adverse effect on our business, operating results, cash flows or financial condition should such litigation be resolved unfavorably.

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PART II

Item 5.    Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Price Range of Common Stock

        Our common stock is publicly traded on the NASDAQ Global Market under the symbol "CPST". The following table sets forth the low and high sales prices for each period indicated.

        As of June 7, 2010, the last reported sale price of our common stock on the NASDAQ Global Market was $1.09 per share.

Stockholders

        As of June 7, 2010 there were 880 stockholders of record of our common stock. This does not include the number of persons whose stock is held in nominee or "street name" accounts through brokers.

Dividend Policy

        We currently intend to retain any earnings for use in our business and, therefore, we do not anticipate paying any cash dividends in the foreseeable future. We have never declared or paid any cash dividends on our capital stock. In the future, the decision to pay any cash dividends will depend upon our results of operations, financial condition, cash flow and capital expenditure plans, as well as such other factors as our Board of Directors, in its sole discretion, may consider relevant, including approval from Wells Fargo.

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Item 6.    Selected Financial Data.

        The selected financial data shown below have been derived from the audited financial statements of Capstone. The historical results are not necessarily indicative of the operating results to be expected in the future. The selected financial data should be read in conjunction with "Risk Factors," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the consolidated financial statements and related notes included elsewhere in this Annual Report.

        Amounts in thousands, except per share data.

 

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Item 7.    Management's Discussion and Analysis of Financial Condition and Results of Operations.

        The following Management's Discussion and Analysis of Financial Condition and Results of Operations contains forward-looking statements that involve risks and uncertainties. Our actual results may differ materially from the results discussed in the forward-looking statements. Factors that might cause a difference include, but are not limited to, those discussed under Item 1A (Risk Factors) in this Annual Report. The following section is qualified in its entirety by the more detailed information, including our financial statements and the notes thereto, which appears elsewhere in this Annual Report.

Overview

        Capstone is, and has been, the market leader in microturbines based on the number of microturbines sold. We were able to significantly increase revenues again this year despite the difficult economic conditions worldwide. Management believes that our efforts on the continued growth and broadening of our distribution network and the stronger than anticipated market acceptance of our new C200 and C1000 Series products were the primary reasons for our growth. In addition, management believes that the oil & gas, high rise buildings, biogas, UPS and hybrid electric vehicle markets will continue to provide strong potential upside opportunities to Capstone in the near term.

        Our Chief Executive Officer, Executive Vice President of Sales & Marketing and Senior Vice President of Customer Service have approximately 60 years of combined experience in distributed generation and co-generation. This team has successfully sold competing products, including GE Energy Jenbacher gas engines, and Caterpillar Inc., Deutz Corporation, Waukesha and other microturbines.

        We continue to focus on improving our products and delivery based on customer input, building brand awareness and new channels to market by developing a diversified network of strategic distribution partners. Our focus is on products and solutions that provide near-term opportunities to drive repeatable business rather than discrete projects for niche markets.

        On February 1, 2010, we entered into an Asset Purchase Agreement with CPS. The Company acquired, subject to an existing license retained by CPS, all of the rights and assets related to the manufacture and sale of the CPS 100 kW ("TA100") microturbine generator, including intellectual property, design, tooling, drawings, patents, know-how, distribution agreements and supply agreements. Pursuant to the transaction, on February 23, 2010, the Company issued to CPS 1,550,387 shares of common stock of the Company and agreed to pay additional consideration of $3.1 million on July 30, 2010. The additional consideration may be paid, at the Company's discretion, in a currently undetermined number of shares, or cash. If settled in common stock, the number of shares of common stock issuable on July 30, 2010 will be equal to $3.1 million divided by the average closing share price of the common stock for the 30-day trading period ending on the trading date immediately preceding the issuance.

        CPS will continue to manufacture the TA100 microturbines for Capstone through March 31, 2011. We have agreed to purchase for cash any remaining TA100 microturbine inventory remaining after March 31, 2011 that has not been consumed as part of the TA100 manufacturing process and is not considered in excess or obsolete and we will obtain title to certain TA100 manufacturing equipment. On the closing date of February 1, 2010, the Company and CPS also entered into an agreement pursuant to which we agreed to purchase 125 kW waste heat recovery generator systems from CPS. In exchange for certain minimum purchase requirements during a three-year period, we have exclusive rights to sell the zero-emission waste heat recovery generator for all microturbine applications and for applications 500 kW or lower where the source of heat is the exhaust of a reciprocating engine used in a landfill application. We must meet specified annual sales targets in order to maintain the exclusive rights to sell the waste heat recovery generators.

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        In order to increase volume and reduce cost, we focus our efforts in vertical markets that we expect to generate repeat business for the Company. To support our opportunities to grow in these markets, we continue to enhance the reliability and performance of our products by regularly developing new processes and enhancing training to assist those who apply, install and use our products.

        An overview of our direction, targets and key initiatives follows:

1)

Focus on Vertical Markets—Within the distributed generation markets that we serve, we focus on vertical markets that we identify as having the greatest near-term potential. In our primary products and applications (CHP and CCHP, resource recovery, hybrid electric vehicles and secure power), we identify specific targeted vertical market segments. Within each of these segments, we identify what we believe to be the critical factors to success base our plans on those factors.

During Fiscal 2010, we booked orders for 77.2 megawatts and shipped 52.8 megawatts of products, resulting in 96.4 megawatts in backlog at the end of the fiscal year. Our actual product shipments in Fiscal 2010 were: 38% for use in CHP applications, 7% for use in CCHP applications, 22% for use in resource recovery applications and 33% for use in other applications (including hybrid electric vehicles and secure power).

2)

Sales and Distribution Channel—We seek out distributors and representatives that have business experience and capabilities to support our growth plans in our targeted markets. In North America, we currently have 38 distributors and OEMs, which includes ten distributors added as a result of the CPS transaction. Internationally, outside of North America, we currently have 55 distributors and OEMs, which includes eight distributors added as a result of the CPS transaction. We continue to refine the distribution channels to address our specific targeted markets.



3)

Service—We serve our customers directly and through qualified distributors and ASCs, all of whom will perform their service work using technicians specifically trained by Capstone. We offer a comprehensive FPP where Capstone charges a fixed annual fee to perform regularly scheduled maintenance, as well as other maintenance as needed. Capstone then performs the required maintenance directly with its own personnel, or contracts with one of its local ASCs to do so. Capstone provides factory and on-site training to certify all personnel that are allowed to perform service on our microturbines. Individuals who are certified are called ASPs and must be employed by an ASC in order to perform work pursuant to a Capstone FPP. The majority of our distributors are ASCs. Our FPP backlog at the end of Fiscal 2010 was $17.1 million which represents the value of the contractual agreement for FPP services that has not been earned and extends through Fiscal 2024. Service revenue in Fiscal 2010 was approximately 8% of total revenue.



4)

Product Robustness and Life Cycle Maintenance Costs—To provide us with the ability to evaluate microturbine performance in the field, we developed a "real-time" remote monitoring and diagnostic feature. This feature allows us to monitor installed units and rapidly collect operating data on a continual basis. We use this information to anticipate and more quickly respond to field performance issues, evaluate component robustness and identify areas for continuous improvement. This feature is important in allowing us to better serve our customers.



5)

New Product Development—Our new product development is targeted specifically to meet the needs of our selected vertical markets. We expect that our existing product platforms, the C30, C60 Series, TA100, C200 and C1000 Series microturbines, will be our foundational product lines for the foreseeable future. Our product development efforts are centered on enhancing

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the features of these base products. Our C200 product beta testing was successfully implemented during Fiscal 2005 and first commercial shipment was on August 28, 2008. Our C1000 Series product was developed based on Capstone's C200 microturbine product line. This product family can be configured into 1,000 kW, 800 kW and 600 kW solutions in a single ISO-sized container. Our C1000 product beta testing was successfully implemented during Fiscal 2009 and the first commercial shipment was on December 29, 2008.

6)

Cost and Core Competencies—We are making progress towards achieving overall cost improvements through design changes, robotics, parts commonality, tier one suppliers and lower cost offshore suppliers. In conjunction with these changes, we launched a strategic supply chain initiative to develop suppliers on a global basis. We continue to review avenues for cost reduction by sourcing to the best value supply chain option. We have made progress diversifying our suppliers internationally and within the United States. Management expects to leverage our costs as product volumes increase.

        Management believes that effective execution in each of these key areas will be necessary to leverage Capstone's promising technology and early market leadership into achieving positive cash flow with growing market presence and improving financial performance. Based on our recent progress and assuming achievement of targeted cost reductions, our financial model indicates that we will achieve positive cash flow when we ship approximately 200 units in a quarter, depending on product mix, which is not reflective of what is in our current backlog.

Critical Accounting Policies

        Our discussion and analysis of our financial condition and results of operations is based upon our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The preparation of these consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenue and expenses and related disclosures of contingent liabilities. On an on-going basis, we evaluate our estimates, including but not limited to those related to long-lived assets, including intangible assets and fixed assets, bad debts, inventories, warranty obligations, stock-based compensation, warrant liabilities, income taxes and contingencies. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

        Management believes that the following critical accounting policies affect our more significant judgments and estimates used in the preparation of our consolidated financial statements.

•

We evaluate the carrying value of long-lived assets, including intangible assets with finite lives, for impairment whenever events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Factors that are considered important that could trigger an impairment review include a current-period operating or cash flow loss combined with a history of operating or cash flow losses and a projection or forecast that demonstrates continuing losses or insufficient income associated with the use of a long-lived asset or asset group. Other factors include a significant change in the manner of the use of the asset or a significant negative industry or economic trend. This evaluation is performed based on undiscounted estimated future cash flows compared with the carrying value of the related assets. If the undiscounted estimated future cash flows are less than the carrying value, an impairment loss is recognized, measured by the difference between the carrying value and the estimated fair value of the assets, with such estimated fair values determined using the best information available, generally the discounted estimated future cash flows of the assets using a rate that approximates our

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weighted-average cost of capital. On a quarterly basis, we assess whether events or changes in circumstances have occurred that potentially indicate the carrying value of long-lived assets may not be recoverable. Intangible assets include a manufacturing license, trade name, technology, backlog and customer relationships. We reevaluate the useful life determinations for these intangible assets each reporting period to determine whether events and circumstances warrant a revision in their remaining useful lives.

The estimation of future cash flows requires significant estimates of factors that include future sales growth, gross margin performance and reductions in operating expenses. This estimation includes the performance of our recently acquired TA100 product line. If our sales growth, gross margin performance or other estimated operating results are not achieved at or above our forecasted level, or inflation exceeds our forecast, the carrying value of our asset groups may prove to be unrecoverable and we may incur impairment charges in the future. A significant assumption in our forecasts is our ability to reduce our direct material costs. Based on our current forecasts, if we were not able to achieve 80% of our cost reduction estimates, our estimated undiscounted cash flows could exceed the carrying value of our long-lived assets, which could result in a future impairment of our long-lived assets. The Company performed an analysis as of March 31, 2010 and determined that the estimated undiscounted cash flows of the long-lived assets exceeded the carrying value of the assets and no write-down was necessary. See Note 5—Intangible Assets in the "Notes to Consolidated Financial Statements."

•

Our inventories are valued at first in first out ("FIFO") and lower of cost or market. We routinely evaluate the composition of our inventories and identify slow-moving, excess, obsolete or otherwise impaired inventories. Inventories identified as impaired are evaluated to determine if write-downs are required. Included in this assessment is a review for obsolescence as a result of engineering changes in our product. Future product enhancement and development may render certain inventories obsolete, resulting in additional write-downs of inventories. In addition, inventories are classified as current or long-term based on our sales forecast. A change in forecast could impact the classification of inventories.



•

We provide for the estimated cost of warranties at the time revenue from sales is recognized. We also accrue the estimated costs to address reliability repairs on products no longer under warranty when, in our judgment, and in accordance with a specific plan developed by us, it is prudent to provide such repairs. We estimate warranty expenses based upon historical and projected product failure rates, estimated costs of parts, labor and shipping to repair or replace a unit and the number of units covered under the warranty period. While we engage in extensive quality programs and processes, our warranty obligation is affected by failure rates and service costs in correcting failures. As we have more units commissioned and longer periods of actual performance, additional data becomes available to assess expected warranty costs. When we have sufficient evidence that product changes are altering the historical failure occurrence rates, the impact of such changes is then taken into account in estimating future warranty liabilities. Changes in estimates are recorded in the period that new information, such as design changes, cost of repair and product enhancements, becomes available. Should actual failure rates or service costs differ from our estimates, revisions to the warranty liability would be required and could be material to our financial condition, results of operations and cash flow.



•

Our revenue consists of sales of products, parts, accessories and service, net of discounts. Our distributors purchase products and parts for sale to end users and are also required to provide a variety of additional services, including application engineering, installation, commissioning and post-commissioning service. Our standard terms of sales to distributors and direct end users include transfer of title, care, custody and control at the point of shipment, payment terms ranging from full payment in advance of shipment to payment in 90 days, no right of return or exchange, and no post-shipment performance obligations by us except for warranties provided on

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the products and parts sold. We recognize revenue when all of the following criteria are met: persuasive evidence of an arrangement exists, delivery has occurred or service has been rendered, selling price is fixed or determinable and collectability is reasonably assured. We occasionally enter into agreements that contain multiple elements, such as equipment, installation, engineering and/or service. For multiple- element arrangements, we recognize revenue for delivered elements when the delivered item has stand-alone value to the customer, fair values of undelivered elements are known and customer acceptance, if required, has occurred.

•

We maintain allowances for doubtful accounts for estimated losses resulting from the inability of our customers to make required payments. We evaluate all accounts aged over 60 days or past payment terms. If the financial condition of our customers deteriorates or if other conditions arise that result in an impairment of their ability or intention to make payments, additional allowances may be required.



•

We have a history of unprofitable operations. These losses generated significant federal and state net operating loss ("NOL") carryforwards. We record a valuation allowance against the net deferred income tax assets associated with these NOLs if it is "more likely than not" that we will not be able to utilize them to offset future income taxes. Because of the uncertainty surrounding the timing of realizing the benefits of our favorable tax attributes in future income tax returns, a valuation allowance has been provided against all of our net deferred income tax assets. We currently provide for income taxes only to the extent that we expect to pay cash taxes, primarily state taxes. It is possible, however, that we could be profitable in the future at levels which could cause management to determine that it is more likely than not that we will realize all or a portion of the NOL carryforwards. Upon reaching such a conclusion, we would record the estimated net realizable value of the deferred income tax asset at that time. Such adjustment would increase income in the period that the determination was made.



•

We record an estimated loss from a loss contingency when information available prior to issuance of our financial statements indicates that it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements and the amount of the loss can be reasonably estimated. Accounting for contingencies, such as legal matters, requires us to use our judgment. Any unfavorable outcome of litigation or other contingencies could have an adverse impact on our financial condition, results of operations and cash flow.



•

We recognize stock-based compensation expense associated with stock options in the statement of operations. Determining the amount of stock-based compensation to be recorded requires us to develop estimates to be used in calculating the grant-date fair value of stock options. We calculate the grant-date fair values using the Black—Scholes valuation model.

The use of Black-Scholes model requires us to make estimates of the following assumptions:

•

Expected volatility—The estimated stock price volatility was derived based upon the Company's actual historic stock prices over the expected option life, which represents the Company's best estimate of expected volatility.



•

Expected option life—For Fiscal 2008, the Company's estimate of an expected option life was calculated in accordance with the Staff Accounting Bulletin No. 107 simplified method for calculating the expected term assumption. In Fiscal 2010 and 2009, the expected life, or term, of options granted was derived from historical exercise behavior and represents the period of time that stock option awards are expected to be outstanding.

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•

Risk-free interest rate—We used the yield on zero-coupon U.S. Treasury securities for a period that is commensurate with the expected life assumption as the risk-free interest rate.

The amount of stock-based compensation recognized during a period is based on the value of the portion of the awards that are ultimately expected to vest. We estimate forfeitures at the time of grant and revise, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The term "forfeitures" is distinct from "cancellations" or "expirations" and represents only the unvested portion of the surrendered option. We review historical forfeiture data and determine the appropriate forfeiture rate based on that data. We re-evaluate this analysis periodically and adjust the forfeiture rate as necessary. Ultimately, we recognize the actual expense over the vesting period only for the shares that vest.

•

As discussed in Note 9—Fair Value Measurements in the "Notes to Consolidated Financial Statements", we adopted the updated guidance of ASC 815, which requires that our warrants be accounted for as derivative instruments and that we mark the value of our warrant liability to market and recognize the change in valuation in our statement of operations each reporting period. Determining the warrant liability to be recorded requires us to develop estimates to be used in calculating the fair value of the warrants. We calculate the fair values using the Black-Scholes valuation model.

The use of the Black-Scholes model requires us to make estimates of the following assumptions:

•

Expected volatility—The estimated stock price volatility was derived based upon the Company's actual historic stock prices over the contractual life of the warrants, which represents the Company's best estimate of expected volatility.



•

Risk-free interest rate—We used the yield on zero-coupon U.S. Treasury securities for a period that is commensurate with the warrant contractual life assumption as the risk-free interest rate.

Results of Operations

Year Ended March 31, 2010 Compared to Year Ended March 31, 2009

        Revenue.    Revenue is reported net of allowances. Revenue for Fiscal 2010 increased $17.7 million, or 40%, to $61.6 million from $43.9 million for Fiscal 2009. The overall revenue increase for Fiscal 2010 compared to Fiscal 2009 included a $9.3 million increase in revenue from the European market, a $6.8 million increase in revenue from the Australian market, a $3.8 million increase in revenue from the South American market and a $0.7 million increase in revenue from the African market, all primarily the result of our efforts to improve distribution channels. This overall increase in revenue was offset by a $2.9 million decrease in revenue from the North American market because of lower sales volume to one of our customers and because Fiscal 2009 included unusually large sales to two customers. Overall microturbine product shipments were slightly higher during Fiscal 2010 compared to Fiscal 2009 totaling 499 units (52.8 megawatts) and 494 units (34.1 megawatts) respectively. Megawatts shipped and revenue during Fiscal 2010 increased as a result of the introduction of our new TA100, C200 and C1000 Series product lines. The average revenue per unit increased to $98,000 in Fiscal 2010 compared to $66,000 per unit for the same period last year because of the benefit of a full twelve months of sales of higher priced C200 and C1000 Series systems, which were introduced during Fiscal 2009. The timing of shipments is subject to change based on several variables (including customer payments and customer delivery schedules), some of which are not within our control and can affect our quarterly revenue and backlog. Therefore, we evaluate historical revenue in conjunction with backlog to anticipate the growth trend of our revenue.

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        The following table summarizes our revenue (revenue amounts in millions):

        Sales to BPC accounted for 14% and 13% of revenues for the year ended March 31, 2010 and 2009, respectively. Sales to Aquatec accounted for 14% and 5% of our revenue for the years ended March 31, 2010 and 2009, respectively. Sales to UTC accounted for 0.2% and 7% of revenue for year ended March 31, 2010 and 2009, respectively.

        Gross Loss.    Cost of goods sold includes direct material costs, production and service center overhead, inventory charges and provision for estimated product warranty expenses. The gross loss was $8.4 million, or 14% of revenue, during Fiscal 2010 compared to $5.3 million, or 12% of revenue, during Fiscal 2009. The increase of $3.1 million in gross loss was the result of increased warranty expense of $2.3 million, increased inventory charges of $1.2 million and $0.6 million related to a change in product mix as we sold more C200 and C1000 Series systems in Fiscal 2010, which currently have a lower margin than our overall average margin mix from Fiscal 2009, as a result of low introductory pricing and initially higher than planned product cost. This is offset by a decrease in our production and service center overhead of $1.0 million.

        Warranty expense is a combination of a per-unit warranty accrual recorded at the time revenue is recognized and changes, if any, in estimates for warranty programs. Warranty program are estimates that are recorded in the period that new information becomes available, including design changes, cost of repair and product enhancements, which can include both in-warranty and out-of-warranty systems. The increase in warranty expense of $2.3 million consisted of a $1.9 million increase for warranty repairs related to C200 and C1000 Series systems, where early production units operating at customer sites were updated for improvements, as the product matured during the year and the increase in the per-unit warranty accrual because of the increased volume of C200 and C1000 Series systems in the field. In addition, the $2.3 million increase also included a $0.4 million increase in warranty programs compared to the prior period because of a higher benefit recorded in the prior period because of warranty program reductions for units subsequently covered by factory protection plans and our expectation that units will operate beyond the estimated warranty failure period.

        The increase in inventory charges of $1.2 million was because of charges related to scrap and yield issues in the manufacturing process of the C200 and C1000 Series products. These charges were offset by decreased production and service center overhead of $1.0 million. The reduction in overhead was a result of our production cost reduction efforts, primarily related to the decrease in manufacturing personnel.

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        Management expects we will continue to incur gross losses until we are able to achieve higher unit sales volumes to cover our fixed manufacturing costs. We have taken steps to further reduce direct material costs and other manufacturing and warranty costs as we work to achieve profitability.

        Research and Development Expenses.    R&D expenses include compensation, engineering department expenses, overhead allocations for administration and facilities and materials costs associated with development. R&D expenses during Fiscal 2010 decreased $1.1 million, or 14%, to $7.0 million from $8.1 million during Fiscal 2009. R&D expenses are reported net of benefits from cost-sharing programs, such as the DOE grant and UTCP funding. There were approximately $1.7 million of such benefits during Fiscal 2010 and $8.1 million of such benefits during Fiscal 2009. There were no in-kind services performed under the cost-sharing programs during Fiscal 2010. In-kind services performed during Fiscal 2009 were valued at $0.2 million and recorded as consulting expenses. The overall decrease in R&D expenses of $1.1 million resulted from decreased spending for consulting expenses of $2.4 million, supplies of $2.4 million, salary expense of $1.3 million, facilities expense of $1.3 million and travel expense of $0.1 million, offset by reduced UTCP funding benefits of $6.4 million for the cost-sharing program, which concluded in June 2009. Cost-sharing programs vary from period to period depending on the phases of the programs. Management expects R&D expenses in Fiscal 2011 to be slightly lower than in Fiscal 2010.

        Selling, General and Administrative ("SG&A") Expenses.    SG&A expenses decreased $0.2 million to $28.4 million during Fiscal 2010 from $28.6 million during Fiscal 2009. The net decrease in SG&A expenses was comprised of a decrease of $1.8 million in salary expense, $1.6 million in travel expense, $0.5 million in consulting services expense and $0.4 million in marketing expense, offset by an increase of $1.8 million in professional services expense, including legal, bank fees, and insurance, $1.0 million in stock-based compensation expense, $0.8 million in facilities expense and $0.5 million in stock-based compensation to consultants. Management expects SG&A expenses in Fiscal 2011 to be slightly lower than in Fiscal 2010.

        Interest Income.    Interest income during Fiscal 2010 decreased to $8,000 from $0.5 million during Fiscal 2009. The decrease during the period was attributable to lower average cash balances and less cash held in interest-bearing accounts. Management expects interest income to increase for Fiscal 2011 as we invest cash received from our February 2010 offering into interest-bearing accounts.

        Interest Expense.    Interest expense during Fiscal 2010 increased to $0.7 million from $0.1 million during Fiscal 2009. Interest expense related to the revolving credit facility with Wells Fargo accounted for the increase in interest expense in Fiscal 2010. As of March 31, 2010, we had total debt of $7.6 million outstanding under the revolving credit facility with Wells Fargo.

        Change in Fair Value of Warrant Liability.    The change in fair value of warrant liability was a charge of $22.9 million during Fiscal 2010. There was no change in fair value of warrant liability during Fiscal 2009. In accordance with ASC 815, adopted in Fiscal 2010, warrants previously classified within equity were reclassified as liabilities. This change in fair value of warrant liability was a result of revaluing the warrant liability based on the Black-Scholes valuation model and the quoted price of the Company's common stock in an active market. This revaluation has no impact on the Company's cash balances.

        Income Tax Provision.    Income taxes during Fiscal 2010 decreased $0.2 million to a tax benefit of $0.1 million from a tax expense of $0.1 million during Fiscal 2009. The decrease in income taxes was related to a R&D tax credit of $0.4 million that was received during Fiscal 2010. At March 31, 2010, we had federal and state net operating loss carryforwards of approximately $576.7 million and $396.9 million, respectively, which may be utilized to reduce future taxable income, subject to limitations under Section 382 of the Internal Revenue Code of 1986. We provided a valuation allowance for 100% of our net deferred tax asset of $235.4 million at March 31, 2010 because the

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realization of the benefits of these favorable tax attributes in future income tax returns is not deemed more likely than not. Similarly, at March 31, 2009, the net deferred tax asset was fully reserved.

Year Ended March 31, 2009 Compared to Year Ended March 31, 2008

        Revenue.    Revenue for Fiscal 2009 increased $12.6 million, or 40%, to $43.9 million from $31.3 million for Fiscal 2008. The overall revenue increase for Fiscal 2009 compared to the previous year included a $9.0 million increase in revenue from the North American market, a $4.6 million increase in revenue from the Asian market, a $1.4 million increase in revenue from the European market, all primarily the result of efforts to improve distribution channels. South American market revenue for Fiscal 2009 was $2.4 million lower than the previous year because Fiscal 2008 included an unusually large product sale for this historically small revenue market. Overall microturbine product shipments were slightly higher during Fiscal 2009 compared to Fiscal 2008 totaling 494 units (34.1 megawatts) and 434 units (22.5 megawatts) respectively. Megawatts shipped and revenue during Fiscal 2009 increased as a result of increased shipments of our C60 Series product and the introduction of our new C200 and C1000 Series product lines. The average revenue per unit increased to $66,000 in Fiscal 2009 compared to $72,000 per unit for Fiscal 2008. The timing of shipments is subject to change based on several variables (including customer payments and customer delivery schedules), some of which are not within our control and can affect our quarterly revenue and backlog. Therefore, we evaluate historical revenue in conjunction with backlog to anticipate the growth trend of our revenue.

        The following table summarizes our revenue (revenue amounts in millions):

        One customer accounted for 13% of revenue for Fiscal 2009. For Fiscal 2008, two customers accounted for 18% and 13% of revenue, respectively. Sales to BPC accounted for 13% and 18% of revenues for Fiscal 2009 and 2008, respectively. Sales to UTC accounted for 7% and 13% of revenue for Fiscal 2009 and 2008, respectively.

        Gross Loss.    The gross loss was $5.3 million, or 12% of revenue, for Fiscal 2009 compared to $3.8 million, or 12% of revenue, for Fiscal 2008. The increase in gross loss reflected increased manufacturing costs of $2.9 million because of the product launch of the C200 and C1000 Series systems offset by an improvement of $0.1 million as a result of a higher margin product mix, primarily because of increased sales of C60 Series systems and reduced warranty expense of $1.3 million. Warranty expense for unit shipments increased slightly as a result of higher shipment volumes and the product launch of the C200 and C1000 Series systems offset by a decrease in the estimated cost of repair. In addition, the warranty expense increase was offset by a $1.3 million reduction in warranty programs because of units subsequently covered by factory protection plans, units decommissioned and our expectation that units will fall outside of the estimated warranty failure period.

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        Research and Development Expenses.    R&D expenses for Fiscal 2009 decreased $0.8 million, or 9%, to $8.1 million from $8.9 million for Fiscal 2008. R&D expenses are reported net of benefits from cost-sharing programs, such as the DOE and the UTCP funding. There were approximately $8.1 million of such benefits for Fiscal 2009 and $3.0 million of such benefits for Fiscal 2008. In-kind services performed by UTCP under the cost-sharing program for each of Fiscal 2009 and 2008 were valued at $0.2 million and recorded as consulting expense. The overall decrease in R&D expenses of $0.8 million resulted from the increased recognition of $5.1 million of funding from UTCP for the cost-sharing program. This benefit was offset by increased spending for supplies of $2.3 million, labor costs of $1.4 million, consulting fees of $0.4 million and facilities expense of $0.2 million. Cost-sharing programs vary from period to period depending on the phases of the programs.

        Selling, General and Administrative Expenses.    SG&A expenses increased $3.0 million, or 12%, to $28.6 million for Fiscal 2009 from $25.6 million for Fiscal 2008. The net increase in SG&A expenses was comprised of an increase of $1.9 million in labor expense, $1.6 million related to travel expense, $0.3 million of marketing expense and $0.1 million in professional services expense, including accounting, legal and insurance expense, offset by a decrease for a change in estimate of legal accruals of $0.4 million, supplies of $0.3 million and consulting expense of $0.2 million. The increase in labor and travel costs reflected the continued effort to develop worldwide distributors and the launch of the C200 and C1000 Series systems.

        Interest Income.    Interest income for Fiscal 2009 decreased $1.7 million, or 77%, to $0.5 million from $2.2 million for Fiscal 2008. The decrease during Fiscal 2009 was attributable to lower average cash balances and interest rates.

        Interest Expense.    Interest expense for Fiscal 2009 increased $62,000, or 886%, to $69,000 from $7,000 for Fiscal 2008. Interest expense related to the revolving credit facility with Wells Fargo accounted for the increase in interest expense in Fiscal 2009.

        Income Tax Provision.    At March 31, 2009, we had federal and state net operating loss carryforwards of approximately $508.6 million and $341.8 million, respectively, which may be utilized to reduce future taxable income, subject to limitations under Section 382 of the Internal Revenue Code of 1986. We provided a valuation allowance for 100% of our net deferred tax asset of $210.6 million at March 31, 2009 because the realization of the benefits of these favorable tax attributes in future income tax returns is not deemed more likely than not. Similarly, at March 31, 2008, the net deferred tax asset was fully reserved.

Quarterly Results of Operations

        The following table presents unaudited quarterly financial information. This information was prepared in accordance with GAAP, and, in the opinion of management, contains all adjustments necessary for a fair presentation of such quarterly information when read in conjunction with the financial statements included elsewhere herein. Our operating results for any prior quarters may not necessarily indicate the results for any future periods.

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        Amounts in thousands, except per share data

Liquidity and Capital Resources

        Our cash requirements depend on many factors, including the execution of our plan. We expect to continue to devote substantial capital resources to running our business and creating the strategic changes summarized herein. Based on our current forecasts and assumptions, we believe that our existing cash and cash equivalents are sufficient to meet our anticipated cash needs for working capital and capital expenditures for at least the next twelve months. Our planned capital expenditures for Fiscal 2011 include approximately $2.0 million for rental units, and plant and equipment costs related to manufacturing and operations. The majority of the $2.0 million relates to the rental units, which can be built primarily from inventory on hand. We have invested our cash in institutional funds that invest in high quality short-term money market instruments to provide liquidity for operations and for capital preservation.

        Our cash and cash equivalent balances increased $27.8 million during the year ended March 31, 2010, compared to a decrease of $23.1 million during the year ended March 31, 2009. The cash was generated from or used in:

Operating Activities—During the year ended March 31, 2010 we used $34.6 million in cash in our operating activities, which primarily consisted of a net loss for the period of approximately $67.2 million, offset by non-cash adjustments (primarily change in fair value of warrant liability, employee stock-based compensation, depreciation and amortization, warranty and inventory charges) of $33.9 million and cash used for working capital of approximately $1.3 million. This compared to operating cash usage of $55.5 million during the year ended March 31, 2009, which consisted of a net loss for the period of approximately $41.7 million, offset by non-cash adjustments (primarily employee stock-based compensation, depreciation and amortization, warranty and inventory charges) of $6.3 million and cash used for working capital of approximately $20.1 million. The change in working capital of $18.8 million was primarily attributable to the change in inventory which had decreased $20.4 million for Fiscal 2010 compared to Fiscal 2009 as a result of our initiatives to reduce inventory. Additionally, the change in working capital was attributable to the change in other current liabilities which had decreased $4.0 million for Fiscal 2010 compared to Fiscal 2009 because of the completion of certain UTCP Development Agreement milestones, offset by accounts receivable which had increased $3.6 million because of the timing and collection of sales, an increase in warranty claims spending of $1.3 million and an increase in accounts payable and accrued expenses of $0.5 million over the same periods because of purchases of inventory.

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Investing Activities—Net cash used in investing activities related primarily to the acquisition of fixed assets of $2.0 million and $6.7 million for Fiscal 2010 and 2009, respectively. Our cash usage for investing activities was relatively low related to capital expenditures compared to Fiscal 2009. However, in Fiscal 2009 we increased cash usage for investing activities as a result of investments in production equipment and leasehold improvements related to the C200 and C1000 Series products.

Financing Activities—During Fiscal 2010, we generated $64.4 million from financing activities compared to cash generated during Fiscal 2009 of $39.2 million. The funds generated from financing activities in Fiscal 2010 were primarily the result of the February 2010 registered offering of our common stock, the September 2009 warrant exercise transaction and the May 2009 registered offering of our common stock and warrants described below.

Effective February 24, 2010, we completed an underwritten offering in which we sold 43.8 million shares of the Company's common stock at a price of $1.05 per share, resulting in gross proceeds of approximately $46.0 million. We incurred approximately $3.6 million in direct costs in connection with the offering.

Effective September 17, 2009, we entered into warrant exercise agreements with the holders (the "Holders") of warrants to purchase an aggregate of 7.2 million shares of the Company's common stock issued by the Company to such Holders on May 7, 2009 (the "Initial Warrants"). Pursuant to the warrant exercise agreements, we agreed to issue and sell to the Holders new warrants to purchase an aggregate of 5.8 million shares of common stock (the "New Warrants") in exchange for the exercise in full of the Initial Warrants at the reduced exercise price of $0.90 per share. The sale of New Warrants resulted in gross proceeds of approximately $0.4 million. The exercise of the Initial Warrants resulted in gross proceeds of approximately $6.5 million.

Effective May 7, 2009, we completed a registered offering in which we sold 14.4 million shares of the Company's common stock and warrants to purchase 10.8 million shares of common stock with an initial exercise price of $0.95 per share, resulting in gross proceeds of approximately $12.5 million. We incurred approximately $1.3 million in direct costs in connection with the offering.

The funds generated from financing activities during Fiscal 2009 were primarily the result of a registered offering of our common stock and warrants, which was completed effective September 23, 2008. The sale resulted in gross proceeds of approximately $32.0 million and proceeds, net of direct transaction costs, of approximately $29.5 million. The exercise of options and warrants yielded approximately $6.1 million in cash during Fiscal 2009.

Employee stock purchases, net of repurchases of shares of our common stock for employee taxes due on vesting of restricted stock units, yielded $0.1 million of cash during each of Fiscal 2010 and 2009. During Fiscal 2010, we generated additional financing from the Credit Facility (defined below) by drawing down our line of credit when funds were available.

        We maintain two Credit and Security Agreements (the "Agreements") with Wells Fargo. The Agreements provide the Company with a line of credit of up to $10 million in the aggregate (the "Credit Facility"). The amount actually available to us may be less and may vary from time to time depending on, among other factors, the amount of eligible inventory and accounts receivable. As security for the payment and performance of the Credit Facility, we granted a security interest in favor of Wells Fargo in substantially all of our assets. The Agreements will terminate in accordance with their terms on February 9, 2012 unless terminated sooner. As of March 31, 2010 and 2009, $7.6 million and $3.7 million in borrowings were outstanding, respectively, under the Credit Facility.

        The Agreements include affirmative covenants as well as negative covenants that prohibit a variety of actions without Wells Fargo's consent, including covenants that limit our ability to (a) incur or

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guarantee debt, (b) create liens, (c) enter into any merger, recapitalization or similar transaction or purchase all or substantially all of the assets or stock of another entity, (d) pay dividends on, or purchase, acquire, redeem or retire shares of, our capital stock, (e) sell, assign, transfer or otherwise dispose of all or substantially all of our assets, (f) change our accounting method or (g) enter into a different line of business. Furthermore, the Agreements contain financial covenants, including (a) a requirement to maintain a specified minimum book worth, (b) a requirement not to exceed specified levels of losses, (c) a requirement to maintain a specified ratio of minimum cash balances to unreimbursed line of credit advances, and (d) limitations on our capital expenditures.

        As of March 31, 2009, we determined that we were not in compliance with financial covenants in the Agreements regarding our net worth and net income. On May 3, 2009, we received from Wells Fargo a waiver of our noncompliance with these two financial covenants as of March 31, 2009 and on June 9, 2009, we amended the Agreements to revise these covenants.

        On September 22, 2009, we received from Wells Fargo a notice of default of our noncompliance with a financial covenant in the Agreements regarding our net worth as of June 30, 2009 and July 31, 2009 and a second financial covenant regarding our net income as of June 30, 2009. On October 28, 2009, we received an additional notice of default regarding our noncompliance with the net worth covenant as of August 31, 2009. These defaults were the result of our adoption of ASC 815 and the increase in C1000 Series sales, which had lower initial margins during the six months ended September 30, 2009. On November 5, 2009, we received from Wells Fargo a waiver of our noncompliance with these covenants and amended the financial covenants in the Agreements to reflect the effects of the new accounting treatment related to the fair value of our warrant liability, effective September 30, 2009, and the fluctuation of product mix, effective September 30, 2009. As a result of the amendment, we were in compliance with the amended financial covenants as of September 30, 2009.

        As of March 31, 2010, we determined that we were not in compliance with the financial covenant in the Agreements regarding our net income. On May 11, 2010, we received a notice of default from Wells Fargo related to our noncompliance. As a result, Wells Fargo imposed default pricing of an additional 3.0% effective March 1, 2010. On June 11, 2010, we received from Wells Fargo a waiver of our noncompliance with the financial covenant as of March 31, 2010 and amended the Agreements to set the covenants for Fiscal 2011. As a condition of the amended Agreements, we have restricted $5.0 million of cash effective June 11, 2010 as additional security for the Credit Facility. If we had not obtained the waiver and amended the Agreements, we would not be able to draw additional funds under the Credit Facility. In addition, we have pledged our accounts receivables, inventories, equipment, patents and other assets as collateral under the Agreements, which would be subject to seizure by Wells Fargo if we were in default under the Agreements and unable to repay the indebtedness. Wells Fargo also has the option to terminate the Agreements or accelerate the indebtedness during a period of noncompliance. Based on our current forecasts, we believe we will maintain compliance with the covenants contained in the amended Agreements for the next twelve months

        Management believes that our existing cash and cash equivalents are sufficient, to meet our anticipated cash needs for working capital and capital expenditures for at least the next twelve months; however, if our anticipated cash needs change, it is possible that we may decide to raise additional capital in the future. We could seek to raise such funds by selling additional securities to the public or to selected investors, or by obtaining debt financing. We cannot provide assurance that we will be able to obtain additional funds on commercially favorable terms, or at all, especially given the state of worldwide capital markets. If we raise additional funds by issuing additional equity or convertible debt securities, the ownership percentages of existing stockholders would be reduced (on a fully diluted basis in the case of convertible securities). In addition, the equity or debt securities that we issue may have rights, preferences or privileges senior to those of the holders of our common stock.

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        Although we believe we have sufficient capital to fund our working capital and capital expenditures for at least the next twelve months, depending on the timing of our future sales and collection of related receivables, managing inventory costs and the timing of inventory purchases and deliveries required to fulfill the current backlog, our future capital requirements may vary materially from those now planned. The amount of capital that we will need in the future will require us to achieve dramatically increased sales volume which is dependent on many factors, including:

•

the market acceptance of our products and services;



•

our business, product and capital expenditure plans;



•

capital improvements to new and existing facilities;



•

our competitors' response to our products and services;



•

our relationships with customers, distributors, dealers and project resellers; and



•

our customers' ability to afford and/or finance our products.

        Additionally, the continued credit crisis could prevent our customers from purchasing our products or delay their purchases, which would adversely affect our business, financial condition and results of operations. In addition, our ability to access the capital markets may be severely restricted or very expensive at a time when we need, or would like, to do so, which could have a material adverse impact on our liquidity and financial resources. Certain industries in which our customers do business and certain geographic areas may have been and could continue to be adversely affected by the recession in economic activity.

        Should we be unable to execute our plans or obtain additional financing that might be needed if our cash needs change, we may be unable to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of these uncertainties.

Contractual Obligations and Commercial Commitments

        At March 31, 2010, our commitments under notes payable, capital leases and non-cancelable operating leases were as follows:

        As of March 31, 2010, we had firm commitments to purchase inventories of approximately $18.9 million through Fiscal 2013. Certain inventory delivery dates and related payments are not firmly scheduled; therefore, amounts under these firm purchase commitments will be payable concurrent with the receipt of the related inventories.

        Agreements we have with some of our distributors and ASCs require that if we render parts obsolete in inventories they own and hold in support of their obligations to serve fielded microturbines, then we are required to replace the affected stock at no cost to the distributors or ASCs. While we have never incurred costs or obligations for these types of replacements, it is possible that future changes in product technology could result and yield costs if significant amounts of inventory are held

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at distributors or ASCs. As of March 31, 2010, no significant inventories were held at distributors or ASCs.

        Pursuant to the terms of our Agreements with Wells Fargo, the minimum interest payable for the Credit Facility is $31,000 each calendar month. The Agreements will terminate in accordance with their terms on February 9, 2012 unless terminated sooner.

Off-Balance Sheet Arrangements

        We do not have any material off-balance sheet arrangements.

Impact of Recently Issued Accounting Standards

        In February 2010, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2010-09, "Subsequent Events (Topic 855)—Amendments to Certain Recognition and Disclosure Requirements" ("ASU 2010-09"). ASU 2010-09 was issued to change certain guidance in the original codification and to clarify other portions. All of the amendments in ASU 2010-09 are effective upon issuance of the final ASU 2010-09, except for the use of the issued date for conduit debt obligors, which is effective for interim or annual periods ending after June 15, 2010. We determined that this updated guidance has no impact on our consolidated financial position or results of operations.

        In January 2010, the FASB issued ASU 2010-06, "Fair Value Measurements and Disclosures (Topic 820)—Improving Disclosures about Fair Value Measurements" ("ASU 2010-06"). ASU 2010-06 provides amended disclosure requirements related to fair value measurements. ASU 2010-06 is effective for interim and annual reporting periods beginning after December 15, 2009, except for the disclosures about purchases, sales, issuances, and settlements in the roll forward of activity in Level 3 fair value measurements. Those disclosures are effective for fiscal years beginning after December 15, 2010, and for interim periods within those fiscal years. Early adoption is permitted. We adopted ASU 2010-06 with no impact on disclosures. See Note 9—Fair Value Measurements in the "Notes to Consolidated Financial Statements" for disclosure regarding the fair value of financial instruments.

        In September 2009, the FASB issued updated guidance of ASC 605, "Revenue Recognition," for establishing the criteria for separating consideration in multiple-element arrangements. The updated guidance is effective for fiscal years beginning on or after June 15, 2010 and requires companies allocating the overall consideration to each deliverable to use an estimated selling price of individual deliverables in the arrangement in the absence of vendor-specific evidence or other third-party evidence of the selling price for the deliverables. The updated guidance also provides additional factors that should be considered when determining whether software in a tangible product is essential to its functionality. We are evaluating any impact that the adoption of this updated guidance may have on our consolidated financial position or results of operations.

        In August 2009, the FASB issued ASU 2009-05, "Fair Value Measurements and Disclosures (Topic 820)—Measuring Liabilities at Fair Value an Update 2009-05" ("ASU 2009-05"). ASU 2009-05 amends subtopic 820-10, "Fair Value Measurements and Disclosures—Overall" and provides clarification for the fair value measurement of liabilities in circumstances where quoted prices for an identical liability in an active market are not available. ASU 2009-05 is effective for the first reporting period beginning after issuance. We adopted ASU 2009-05 with no impact on our consolidated financial position or results of operations.

        Effective July 1, 2009, we adopted the FASB ASC 105, "Generally Accepted Accounting Principles—Overall" ("ASC 105"). ASC 105 establishes the FASB Accounting Standards Codification (the "Codification") as the source of authoritative accounting principles recognized by the FASB to be applied by nongovernmental entities in the preparation of financial statements in conformity with

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GAAP. Rules and interpretive releases of the SEC under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. All guidance contained in the Codification carries an equal level of authority. The Codification superseded all existing non-SEC accounting and reporting standards. All other non-grandfathered, non-SEC accounting literature not included in the Codification is non-authoritative. The FASB will not issue any new standards in the form of Statements, FASB Staff Positions or Emerging Issues Task Force Abstracts. Instead, it will issue ASUs. The FASB will not consider ASUs as authoritative in their own right. ASUs will serve only to update the Codification, provide background information about the guidance and provide the bases for conclusions on the change(s) in the Codification. References made to FASB guidance throughout this document have been updated for the Codification.

        In May 2009, the FASB issued ASC 855, "Subsequent Events" ("ASC 855"). This should not result in significant changes in the subsequent events that an entity reports. Rather, ASC 855 introduces the concept of financial statements being available to be issued. Financial statements are considered available to be issued when they are complete in a form and format that complies with GAAP and all approvals necessary for issuance have been obtained. We adopted ASC 855 with no impact on our consolidated financial position or results of operations. See Note 1—Description of the Company and Basis of Presentation in the "Notes to Consolidated Financial Statements" for further discussion.

        In April 2009, the FASB issued updated guidance of ASC 820, "Fair Value Measurements." The updated guidance is effective for interim and annual periods ending after June 15, 2009 and provides guidance on how to determine the fair value of assets and liabilities in the current economic environment and reemphasizes that the objective of a fair value measurement remains an exit price. If we were to conclude that there has been a significant decrease in the volume and level of activity of the asset or liability in relation to normal market activities, quoted market values may not be representative of fair value and we may conclude that a change in valuation technique or the use of multiple valuation techniques may be appropriate. The updated guidance modifies the requirements for recognizing other-than-temporarily impaired debt securities and revises the existing impairment model for such securities by modifying the current intent and ability indicator in determining whether a debt security is other-than-temporarily impaired. The updated guidance also enhances the disclosure of instruments for both interim and annual periods. We adopted this updated guidance with no impact on our consolidated financial position or results of operations. See Note 9—Fair Value Measurements in the "Notes to Consolidated Financial Statements", for disclosure regarding the fair value of financial instruments.

        In June 2008, the FASB issued updated guidance of ASC 815, "Derivatives and Hedging" ("ASC 815"), that is effective for financial statements issued for fiscal years beginning after December 15, 2008, and interim periods within those fiscal years. Early application is not permitted. The updated guidance specifies that a contract that would otherwise meet the definition of a derivative but is both (a) indexed to our own stock and (b) classified in stockholders' equity in the statement of financial position would not be considered a derivative financial instrument. The updated guidance provides a new two-step model to be applied in determining whether a financial instrument or an embedded feature is indexed to an issuer's own stock and is able to qualify for the scope exception. The adoption of this updated guidance affects our accounting for warrants with certain anti-dilution provisions. Warrants with certain anti-dilution provisions may no longer be recorded as equity. We adopted this updated guidance as of April 1, 2009. See Note 9—Fair Value Measurements in the "Notes to Consolidated Financial Statements", for disclosure regarding the fair value of financial instruments.

        In April 2008, the FASB issued updated guidance of ASC 350, "Intangibles—Goodwill and Other," removing the requirement for an entity to consider, when determining the useful life of an acquired intangible asset, whether the intangible asset can be renewed without substantial cost or material modifications to the existing terms and conditions associated with the intangible asset. The intent of the

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updated guidance is to improve the consistency between the useful life of a recognized intangible asset and the period of expected cash flows used to measure the fair value of the asset under ASC 805, "Business Combinations," and other U.S. generally accepted accounting principles. The updated guidance replaces the previous useful-life assessment criteria with a requirement that an entity considers its own experience in renewing similar arrangements. This updated guidance applies to all intangible assets, whether acquired in a business combination or otherwise and shall be effective for financial statements issued for fiscal years beginning after December 15, 2008, and interim periods within those fiscal years and applied prospectively to intangible assets acquired after the effective date. We determined that this updated guidance has no impact on our consolidated financial position or results of operations.

        In March 2008, the FASB issued updated guidance of ASC 815, "Derivatives and Hedging" which is effective for fiscal years and interim periods beginning after November 15, 2008, with earlier adoption encouraged. This updated guidance is intended to improve transparency in financial reporting by requiring enhanced disclosures of the Company's derivative instruments and hedging activities and their effects on the Company's financial position, financial performance, and cash flows. This updated guidance applies to all derivative instruments, as well as related hedged items, bifurcated derivatives, and nonderivative instruments that are designated and qualify as hedging instruments. The updated guidance impacts only the Company's disclosure requirements and therefore will not have an impact on the Company's consolidated financial position or results of operations. We adopted the updated guidance and included the additional required disclosures. See Note 9—Fair Value Measurements in the "Notes to Consolidated Financial Statements", for disclosure of derivative instruments.

        In December 2007, the FASB issued updated guidance of ASC 810, "Consolidation." This updated guidance establishes accounting and reporting standards for ownership interests in subsidiaries held by parties other than the parent, the amount of consolidated net income attributable to the parent and to the noncontrolling interest, changes in a parent's ownership interest and the valuation of retained noncontrolling equity investments when a subsidiary is deconsolidated. The updated guidance also establishes reporting requirements that provide sufficient disclosures that clearly identify and distinguish between the interests of the parent and the interests of the noncontrolling owners. This updated guidance was effective for fiscal years beginning after December 15, 2008. We determined that this updated guidance has no impact on our consolidated financial position or results of operations.

Item 7A.    Quantitative and Qualitative Disclosure About Market Risk.

Foreign Currency

        We currently develop products in the U.S. and market and sell our products predominantly in North America, Europe and Asia. As a result, factors such as changes in foreign currency exchange rates or weak economic conditions in foreign markets could affect our financial results. As all of our sales and purchases are currently made in U.S. dollars, we do not utilize foreign exchange contracts to reduce our exposure to foreign currency fluctuations. In the future, as our customers, employees and vendor bases expand, we anticipate entering into more transactions that are denominated in foreign currencies.

Interest

        As of March 31, 2010, we had $7.6 million outstanding under our Credit Facility. A hypothetical 2% change in interest rates would not have any effect on our interest expense or interest payments because interest on our Credit Facility balance of $7.6 million as of March 31, 2010 would still be lower than the minimum interest payment of approximately $31,000 each calendar month payable pursuant to the Credit Facility.

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Item 8.    Financial Statements and Supplementary Data.

        Our Consolidated Financial Statements and Financial Statement Schedule included in this Annual Report beginning at page F-1 are incorporated in this Item 8 by reference.

Item 9.    Changes in and Disagreements with Accountants on Accounting and Financial Disclosure.

        None.

Item 9A.    Controls and Procedures.

Disclosure Controls and Procedures

        We maintain disclosure controls and procedures that are designed to ensure that the information required to be disclosed in the Company's reports under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), is recorded, processed, summarized, and reported within the time periods specified in the SEC's rules and forms, and that such information is accumulated and communicated to management, including our Chief Executive Officer ("CEO") and Chief Financial Officer ("CFO"), as appropriate, to allow timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, management recognized that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives.

        In connection with the preparation of this Annual Report on Form 10-K for the year ended March 31, 2010, an evaluation was performed under the supervision and with the participation of our management, including the CEO and CFO, of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Exchange Act). Based on this evaluation, our CEO and CFO have concluded that our disclosure controls and procedures are effective as of March 31, 2010 to ensure that the information required to be disclosed by us in reports we submit under the Exchange Act is recorded, processed, summarized, and reported within the time periods specified in the rules and forms of the SEC and that such information is accumulated and communicated to management, including our CEO and CFO, as appropriate, to allow timely decisions regarding required disclosure.

Management's Annual Report on Internal Control Over Financial Reporting

        Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f). Under the supervision and with the participation of our management, including our CEO and CFO, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organization of the Treadway Commission. Based on our evaluation under the framework in Internal Control—Integrated Framework, our management concluded that the Company maintained effective internal control over financial reporting as of March 31, 2010. Deloitte & Touche LLP, the Company's independent registered public accounting firm, has issued a report on the Company's internal control over financial reporting. The report of Deloitte & Touch LLP follows. Projections of any evaluation of effectiveness to future periods are subject to the risks that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Changes in Internal Control Over Financial Reporting

        There were no changes in the Company's internal control over financial reporting during the three month period ended March 31, 2010 which have materially affected, or are reasonably likely to materially affect, the Company's internal control over financial reporting.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and Stockholders of
Capstone Turbine Corporation
Chatsworth, California

        We have audited the internal control over financial reporting of Capstone Turbine Corporation and subsidiary (the "Company") as of March 31, 2010, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission. The Company's management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management's Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company's internal control over financial reporting based on our audit.

        We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

        A company's internal control over financial reporting is a process designed by, or under the supervision of, the company's principal executive and principal financial officers, or persons performing similar functions, and effected by the company's board of directors, management, and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

        Because of the inherent limitations of internal control over financial reporting, including the possibility of collusion or improper management override of controls, material misstatements due to error or fraud may not be prevented or detected on a timely basis. Also, projections of any evaluation of the effectiveness of the internal control over financial reporting to future periods are subject to the risk that the controls may become inadequate because of changes in conditions or that the degree of compliance with the policies or procedures may deteriorate.

        In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of March 31, 2010, based on the criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission.

        We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated financial statements and financial statement schedule as of and for the year ended March 31, 2010 of the Company and our report dated June 14, 2010 expressed an unqualified opinion on those financial statements and financial statement schedule and

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includes an explanatory paragraph regarding Capstone Turbine Corporation's adoption of the guidance originally issued in Emerging Issues Task Force No. 07-05, "Determining Whether an Instrument (or Embedded Feature) is Indexed on an Entity's Own Stock", (codified in FASB ASC Topic 815—Derivatives and Hedging), effective April 1, 2009.

/s/ DELOITTE & TOUCHE LLP
Los Angeles, California
June 14, 2010

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Item 9B.    Other Information.

        None.

PART III

Item 10.    Directors, Executive Officers and Corporate Governance.

Directors

        Information contained under the caption "Proposal 1: Election of Directors to the Board of Directors" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Executive Officers

        Information contained under the caption "Executive Officers of the Company" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Compliance with Section 16(a) of the Exchange Act

        Information contained under the caption "Other Information—Section 16(a) Beneficial Ownership Reporting Compliance" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Code of Ethics

        Information contained under the caption "Other Information—Code of Business Conduct and Code of Ethics" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Stockholder Nominees

        Information contained under the caption "Governance of the Company and Practices of the Board of Directors—Director Recommendation and Nomination Process" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Audit and Compliance Committee

        Information contained under the caption "Governance of the Company and Practices of the Board of Directors—Board Committees—Audit Committee" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Item 11.    Executive Compensation.

        Information contained under the captions "Compensation Discussion and Analysis," "Executive Compensation," "Compensation of Directors," "Compensation Committee Interlocks and Insider Participation" and "Compensation Committee Report" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

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Item 12.    Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

Equity Compensation Plan Information

        Information contained under the caption "Securities Authorized for Issuance under Equity Compensation Plans" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Security Ownership of Certain Beneficial Owners and Management

        Information contained under the caption "Security Ownership of Certain Beneficial Owners and Management" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Item 13.    Certain Relationships and Related Transactions, and Director Independence.

        Information contained under the captions "Other Information—Related Person Transactions Policies and Procedures" and "Governance of the Company and Practices of the Board of Directors—Board of Directors" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

Item 14.    Principal Accountant Fees and Services.

        Information contained under the caption "Fees and Services of the Independent Registered Public Accounting Firm" included in our proxy statement relating to our 2010 annual meeting of stockholders is incorporated herein by reference.

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PART IV

Item 15.    Exhibits and Financial Statement Schedules.

(a) 1. and 2.    Financial statements and financial statement schedule

        The financial statements, notes and financial statement schedule are listed in the Index to Consolidated Financial Statements on page F-1 of this Report.

(a) 3.    Index to Exhibits.

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY
INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

        Financial statement schedules not included in this Annual Report on Form 10-K have been omitted because they are not applicable or the required information is shown in the financial statements or notes thereto.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and Stockholders of
Capstone Turbine Corporation
Chatsworth, California

        We have audited the accompanying consolidated balance sheets of Capstone Turbine Corporation and subsidiary (the "Company") as of March 31, 2010 and 2009 and the related consolidated statements of operations, stockholders' equity, and cash flows for each of the three years in the period ended March 31, 2010. Our audits also included the financial statement schedule listed in the Index at Item 15. These financial statements and financial statement schedule are the responsibility of the Company's management. Our responsibility is to express an opinion on the financial statements and financial statement schedule based on our audits.

        We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

        In our opinion, such consolidated financial statements present fairly, in all material respects, the financial position of the Company as of March 31, 2010 and 2009, and the results of its operations and its cash flows for each of the three years in the period ended March 31, 2010, in conformity with accounting principles generally accepted in the United States of America. Also, in our opinion, such financial statement schedule, when considered in relation to the basic consolidated financial statements taken as a whole, presents fairly, in all material respects, the information set forth therein.

        As discussed in Note 2 and Note 9 to the consolidated financial statements, the Company changed its method of accounting for warrants with anti-dilution provisions with the adoption of the guidance originally issued in Emerging Issues Task Force No. 07-05, "Determining Whether an Instrument (or Embedded Feature) is Indexed to an Entity's Own Stock" (codified in FASB ASC Topic 815—Derivatives and Hedging), effective April 1, 2009.

        We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the Company's internal control over financial reporting as of March 31, 2010, based on the criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated June 14, 2010 expressed an unqualified opinion on the Company's internal control over financial reporting.

/s/ DELOITTE & TOUCHE LLP
Los Angeles, California
June 14, 2010

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

CONSOLIDATED BALANCE SHEETS

(In thousands, except share amounts)

See accompanying notes to consolidated financial statements.

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

See accompanying notes to consolidated financial statements.

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY

(In thousands, except share amounts)

See accompanying notes to consolidated financial statements.

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

CONSOLIDATED STATEMENTS OF CASH FLOWS (Continued)

(In thousands)

See accompanying notes to consolidated financial statements.

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CAPSTONE TURBINE CORPORATION AND SUBSIDIARY

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Description of the Company and Basis of Presentation

        Capstone Turbine Corporation (the "Company") develops, manufactures, markets and services microturbine technology solutions for use in stationary distributed power generation applications, including cogeneration (combined heat and power ("CHP"), integrated combined heat and power ("ICHP"), and combined cooling, heat and power ("CCHP")), resource recovery (including "renewable" fuels) and secure power. In addition, the Company's microturbines can be used as battery charging generators for hybrid electric vehicle applications. The Company was organized in 1988 and has been commercially producing its microturbine generators since 1998.

        The Company has incurred significant operating losses since its inception. Management anticipates incurring additional losses until the Company can produce sufficient revenue to cover its operating costs. To date, the Company has funded its activities primarily through private and public equity offerings. As of March 31, 2010, the Company had $86.3 million, or 726 units, in backlog, all of which are expected to be shipped within the next twelve months. However, the timing of shipments is subject to change based on several variables (including customer payments and changes in customer delivery schedules), some of which are beyond the Company's control and can affect the Company's revenue and backlog. Management believes that existing cash and cash equivalents are sufficient to meet the Company's anticipated cash needs for working capital and capital expenditures for at least the next twelve months. However, if anticipated cash needs of the Company change, it is possible that the Company may decide to raise additional capital in the future. The Company could raise such funds by selling additional securities to the public or to selected investors, or by obtaining debt financing. If the Company raises additional funds by issuing additional equity or convertible debt securities, the fully diluted ownership percentages of existing stockholders would be reduced. In addition, any equity or debt securities that it would issue may have rights, preferences or privileges senior to those of the holders of its common stock. Should the Company be unable to execute its plans or obtain additional financing that might be needed if the Company's cash needs change, the Company may be unable to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of these uncertainties

        The consolidated financial statements include the accounts of the Company and Capstone Turbine International, Inc., its wholly owned subsidiary that was formed in June 2004, after elimination of inter-company transactions.

        The Company has conducted a subsequent events review through the date the financial statements were issued, and has concluded that there were no subsequent events requiring adjustments or additional disclosures to the Company's financial statements at March 31, 2010.

2. Summary of Significant Accounting Policies

        Cash Equivalents    The Company considers only those investments that are highly liquid and readily convertible to cash with original maturities of three months or less at date of purchase as cash equivalents.

        Restricted Cash    As of March 31, 2008, the Company had set aside $33,000, that was included in other assets to cover warranty related issues in connection with a performance guarantee. The restricted cash was replaced by a letter of credit for $36,000 during Fiscal 2009. This performance guarantee covers a period of 18 months and expired in May 2009.

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        Fair Value of Financial Instruments    The carrying value of certain financial instruments, including cash equivalents, accounts receivable, accounts payable, revolving credit facility and notes payable approximate fair market value based on their short-term nature. See Note 9—Fair Value Measurements, for disclosure regarding the fair value of financial instruments.

        Accounts Receivable    The Company maintains allowances for doubtful accounts for estimated losses resulting from the inability of customers to make required payments.

        Inventories    The Company values inventories at first in first out ("FIFO") and lower of cost or market. The composition of inventory is routinely evaluated to identify slow-moving, excess, obsolete or otherwise impaired inventories. Inventories identified as impaired are evaluated to determine if write-downs are required. Included in the assessment is a review for obsolescence as a result of engineering changes in the Company's products. All inventories expected to be used in more than one year are classified as long-term.

        Depreciation and Amortization    Depreciation and amortization are provided for using the straight-line method over the estimated useful lives of the related assets, ranging from two to ten years. Leasehold improvements are amortized over the period of the lease or the estimated useful lives of the assets, whichever is shorter, with the exception of the backlog of 100 kW microturbines ("TA100") acquired from Calnetix Power Solutions, Inc. ("CPS"). Intangible assets that have finite useful lives are amortized over their estimated useful lives using the straight-line method. Purchased backlog is amortized based on unit sales.

        Long-Lived Assets    The Company reviews the recoverability of long-lived assets, including intangible assets with finite lives, whenever events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. If the expected future cash flows from the use of such assets (undiscounted and without interest charges) are less than the carrying value, the Company may be required to record a write-down, which is determined based on the difference between the carrying value of the assets and their estimated fair value. The Company performed an analysis as of March 31, 2010 and determined that the estimated undiscounted cash flows of the long-lived assets exceeded the carrying value of the assets and no write-down was necessary. Intangible assets include a manufacturing license, trade name, technology, backlog and customer relationships. See Note 5—Intangible Assets.

        The estimation of future cash flows requires significant estimates of factors that include future sales growth, gross margin performance and reductions in operating expenses. If our sales growth, gross margin performance or other estimated operating results are not achieved at or above our forecasted level, or inflation exceeds our forecast the carrying value of our asset groups may prove to be unrecoverable and we may incur impairment charges in the future.

        Deferred Revenue    Deferred revenue consists of deferred product and service revenue and customer deposits. Deferred revenue will be recognized when earned in accordance with the Company's revenue recognition policy. The Company has the right to retain all or part of customer deposits under certain conditions.

        Revenue    The Company's revenue consists of sales of products, parts and accessories and service, net of discounts. Capstone's distributors purchase products and parts for sale to end users and are also required to provide a variety of additional services, including application engineering, installation,

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commissioning and post-commissioning repair and maintenance service. The Company's standard terms of sales to distributors and direct end-users include transfer of title, care, custody and control at the point of shipment, payment terms ranging from full payment in advance of shipment to payment in 90 days, no right of return or exchange, and no post-shipment performance obligations by Capstone except for warranties provided on the products and parts sold. Revenue is generally recognized and earned when all of the following criteria are satisfied: (a) persuasive evidence of a sales arrangement exists; (b) price is fixed or determinable; (c) collectibility is reasonably assured; and (d) delivery has occurred or service has been rendered. Delivery generally occurs when the title and the risks and rewards of ownership have substantially transferred to the customer. To date, the Company has not had significant levels of service revenue. Service performed by the Company has consisted primarily of commissioning and time and materials based contracts. The time and materials contracts are usually related to out-of-warranty units. Service revenue derived from time and materials contracts is recognized as performed. The Company also provides maintenance service contracts to customers of its existing install base. The maintenance service contracts are agreements to perform certain agreed-upon service to maintain a product for a specified period of time. Service revenue derived from maintenance service contracts is recognized on a straight-line basis over the contract period. The Company occasionally enters into agreements that contain multiple elements, such as sale of equipment, installation, engineering and/or service. For multiple-element arrangements, the Company recognizes revenue for delivered elements when the delivered item has stand- alone value to the customer, fair values of undelivered elements are known and customer acceptance provisions, if any, have occurred.

        Warranty    The Company provides for the estimated costs of warranties at the time revenue is recognized. The specific terms and conditions of those warranties vary depending upon the product sold, geography of sale and the length of extended warranties sold. The Company's product warranties generally start from the delivery date and continue for up to eighteen months. Factors that affect the Company's warranty obligation include product failure rates, anticipated hours of product operations and costs of repair or replacement in correcting product failures. These factors are estimates that may change based on new information that becomes available each period. Similarly, the Company also accrues the estimated costs to address reliability repairs on products no longer in warranty when, in the Company's judgment, and in accordance with a specific plan developed by the Company, it is prudent to provide such repairs. The Company assesses the adequacy of recorded warranty liabilities quarterly and makes adjustments to the liability as necessary. When the Company has sufficient evidence that product changes are altering the historical failure occurrence rates, the impact of such changes is then taken into account in estimating future warranty liabilities.

        Research and Development ("R&D")    The Company accounts for grant distributions and development funding as offsets to R&D expenses and are recorded as the related costs are incurred. Total offsets to R&D expenses amounted to $1.7 million, $8.1 million and $3.0 million, for the years ended March 31, 2010, 2009 and 2008, respectively.

        Income Taxes    Deferred income tax assets and liabilities are computed for differences between the consolidated financial statement and income tax basis of assets and liabilities. Such deferred income tax asset and liability computations are based on enacted tax laws and rates applicable to periods in which the differences are expected to reverse. Valuation allowances are established, when necessary, to reduce deferred income tax assets to the amounts expected to be realized.

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        Contingencies    The Company records an estimated loss from a loss contingency when information available prior to issuance of its financial statements indicates that it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements and the amount of the loss can be reasonably estimated.

        Risk Concentrations    Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The Company places its cash and cash equivalents with high credit quality institutions. The Company performs ongoing credit evaluations of its customers and maintains an allowance for potential credit losses.

        The Company sells microturbines and related parts and service. Two customers each accounted for 14% of the Company's revenue for the year ended March 31, 2010. One of these customers accounted for 20% of the Company's net accounts receivable and another customer accounted for 16% of net accounts receivable as of March 31, 2010, respectively. One customer accounted for 13% of the Company's revenue for the year ended March 31, 2009. One customer accounted for 29% of net accounts receivable as of March 31, 2009. Two customers accounted for 18% and 13% of the Company's revenue for the year ended March 31, 2008.

        Several components of the Company's products are available from a limited number of suppliers. An interruption in supply could cause a delay in manufacturing and a possible loss of sales, which would affect operating results adversely.

        Estimates and Assumptions    The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates include accounting for doubtful accounts, stock-based compensation, inventory write-downs, valuation of long-lived assets including intangible assets with finite lives, product warranties, income taxes and other contingencies. Actual results could differ from those estimates.

        Net Loss Per Common Share    Basic loss per common share is computed using the weighted-average number of common shares outstanding for the period. Diluted loss per share is also computed without consideration to potentially dilutive instruments because the Company incurred losses which would make such instruments antidilutive. Outstanding stock options at each of March 31, 2010, 2009 and 2008 were 9.2 million. Outstanding restricted stock units at March 31, 2010, 2009 and 2008 were 1.7 million, 2.5 million and 2.3 million, respectively. As of March 31, 2010, 2009 and 2008, the number of warrants excluded from diluted net loss per common share computations was approximately 34.1 million, 23.7 million and 18.5 million, respectively.

        Stock-Based Compensation    Options or stock awards are recorded at their estimated fair value at the measurement date.

        Restructuring Costs    In February 2010, the Company eliminated 28 employees, or 13% of its workforce. As a result of this restructuring activity, $0.2 million in severance costs were expensed during Fiscal 2010. As of March 31, 2010, the Company had approximately $44,000 in remaining severance cost accruals recorded and scheduled for payment during the first quarter of Fiscal 2011. Beginning in December 2008 and continuing into March 2009, the Company eliminated 42 employees, or 17%, of its workforce. As a result of this restructuring activity, $0.6 million in severance costs were

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expensed during Fiscal 2009. As of March 31, 2009, the Company had $0.2 million in remaining severance costs accrued which were paid during the first quarter of Fiscal 2010.

        Segment Reporting    The Company is considered to be a single operating segment. The business activities of this operating segment are the development, manufacture and sale of turbine generator sets and their related parts and service. Following is the geographic revenue information based on the primary operating location of the Company's customers:

        The following table summarizes our revenue by product:

        Substantially all of the Company's operating assets are in the United States.

        Recent Accounting Pronouncements    In February 2010, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2010-09, "Subsequent Events (Topic 855)—Amendments to Certain Recognition and Disclosure Requirements" ("ASU 2010-09"). ASU 2010-09 was issued to change certain guidance in the original codification and to clarify other portions. All of

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the amendments in ASU 2010-09 are effective upon issuance of the final ASU 2010-09, except for the use of the issued date for conduit debt obligors. That amendment is effective for interim or annual periods ending after June 15, 2010. The Company determined that this updated guidance has no impact on its consolidated financial position or results of operations.

        In January 2010, the FASB issued ASU 2010-06, "Fair Value Measurements and Disclosures (Topic 820)—Improving Disclosures about Fair Value Measurements" ("ASU 2010-06"). ASU 2010-06 provides amended disclosure requirements related to fair value measurements. ASU 2010-06 is effective for interim and annual reporting periods beginning after December 15, 2009, except for the disclosures about purchases, sales, issuances, and settlements in the roll forward of activity in Level 3 fair value measurements. Those disclosures are effective for fiscal years beginning after December 15, 2010, and for interim periods within those fiscal years. Early adoption is permitted. The Company adopted ASU 2010-06 with no impact on disclosures. See Note 9—Fair Value Measurements, for disclosure regarding the fair value of financial instruments.

        In September 2009, the FASB issued updated guidance of Accounting Standards Codification ("ASC") 605, "Revenue Recognition," for establishing the criteria for separating consideration in multiple-element arrangements. The updated guidance is effective for fiscal years beginning on or after June 15, 2010 and requires companies allocating the overall consideration to each deliverable to use an estimated selling price of individual deliverables in the arrangement in the absence of vendor-specific evidence or other third-party evidence of the selling price for the deliverables. The updated guidance also provides additional factors that should be considered when determining whether software in a tangible product is essential to its functionality. The Company is evaluating any impact that the adoption of this updated guidance may have on its consolidated financial position or results of operations.

        In August 2009, the FASB issued ASU 2009-05, "Fair Value Measurements and Disclosures (Topic 820)—Measuring Liabilities at Fair Value an Update 2009-05" ("ASU 2009-05"). ASU 2009-05 amends subtopic 820-10, "Fair Value Measurements and Disclosures—Overall" and provides clarification for the fair value measurement of liabilities in circumstances where quoted prices for an identical liability in an active market are not available. ASU 2009-05 is effective for the first reporting period beginning after issuance. The Company adopted ASU 2009-05 with no impact on its consolidated financial position or results of operations.

        Effective July 1, 2009, the Company adopted the FASB ASC 105, "Generally Accepted Accounting Principles—Overall" ("ASC 105"). ASC 105 establishes the FASB Accounting Standards Codification (the "Codification") as the source of authoritative accounting principles recognized by the FASB to be applied by nongovernmental entities in the preparation of financial statements in conformity with GAAP. Rules and interpretive releases of the Securities and Exchange Commission ("SEC") under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. All guidance contained in the Codification carries an equal level of authority. The Codification superseded all existing non-SEC accounting and reporting standards. All other non-grandfathered, non-SEC accounting literature not included in the Codification is non-authoritative. The FASB will not issue any new standards in the form of Statements, FASB Staff Positions or Emerging Issues Task Force Abstracts. Instead, it will issue ASUs. The FASB will not consider ASUs as authoritative in their own right. ASUs will serve only to update the Codification, provide background information about the

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guidance and provide the bases for conclusions on the change(s) in the Codification. References made to FASB guidance throughout this document have been updated for the Codification.

        In May 2009, the FASB issued ASC 855, "Subsequent Events" ("ASC 855"). This should not result in significant changes in the subsequent events that an entity reports. Rather, ASC 855 introduces the concept of financial statements being available to be issued. Financial statements are considered available to be issued when they are complete in a form and format that complies with GAAP and all approvals necessary for issuance have been obtained. The Company adopted ASC 855 with no impact on its consolidated financial position or results of operations. See Note 1—Description of the Company and Basis of Presentation, for further discussion.

        In April 2009, the FASB issued updated guidance of ASC 820, "Fair Value Measurements." The updated guidance is effective for interim and annual periods ending after June 15, 2009 and provides guidance on how to determine the fair value of assets and liabilities in the current economic environment and reemphasizes that the objective of a fair value measurement remains an exit price. If the Company were to conclude that there has been a significant decrease in the volume and level of activity of the asset or liability in relation to normal market activities, quoted market values may not be representative of fair value and the Company may conclude that a change in valuation technique or the use of multiple valuation techniques may be appropriate. The updated guidance modifies the requirements for recognizing other-than-temporarily impaired debt securities and revises the existing impairment model for such securities by modifying the current intent and ability indicator in determining whether a debt security is other-than-temporarily impaired. The updated guidance also enhances the disclosure of instruments for both interim and annual periods. The Company adopted this updated guidance with no impact on its consolidated financial position or results of operations. See Note 9—Fair Value Measurements, for disclosure regarding the fair value of financial instruments.

        In June 2008, the FASB issued updated guidance of ASC 815, "Derivatives and Hedging" ("ASC 815"), that is effective for financial statements issued for fiscal years beginning after December 15, 2008, and interim periods within those fiscal years. Early application is not permitted. The updated guidance specifies that a contract that would otherwise meet the definition of a derivative but is both (a) indexed to the Company's own stock and (b) classified in stockholders' equity in the statement of financial position would not be considered a derivative financial instrument. The updated guidance provides a new two-step model to be applied in determining whether a financial instrument or an embedded feature is indexed to an issuer's own stock and is able to qualify for the scope exception. The adoption of this updated guidance affects the Company's accounting for warrants with certain anti-dilution provisions. Warrants with certain anti-dilution provisions may no longer be recorded as equity. The Company adopted this updated guidance as of April 1, 2009. See Note 9—Fair Value Measurements, for disclosure regarding the fair value of financial instruments.

        In April 2008, the FASB issued updated guidance of ASC 350, "Intangibles—Goodwill and Other," removing the requirement for an entity to consider, when determining the useful life of an acquired intangible asset, whether the intangible asset can be renewed without substantial cost or material modifications to the existing terms and conditions associated with the intangible asset. The intent of the updated guidance is to improve the consistency between the useful life of a recognized intangible asset and the period of expected cash flows used to measure the fair value of the asset under ASC 805, "Business Combinations," and other U.S. generally accepted accounting principles. The updated guidance replaces the previous useful-life assessment criteria with a requirement that an entity

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considers its own experience in renewing similar arrangements. This updated guidance applies to all intangible assets, whether acquired in a business combination or otherwise and shall be effective for financial statements issued for fiscal years beginning after December 15, 2008, and interim periods within those fiscal years and applied prospectively to intangible assets acquired after the effective date. The Company determined that this updated guidance has no impact on its consolidated financial position or results of operations.

        In March 2008, the FASB issued updated guidance of ASC 815, "Derivatives and Hedging" which is effective for fiscal years and interim periods beginning after November 15, 2008, with earlier adoption encouraged. This updated guidance is intended to improve transparency in financial reporting by requiring enhanced disclosures of the Company's derivative instruments and hedging activities and their effects on the Company's financial position, financial performance, and cash flows. This updated guidance applies to all derivative instruments, as well as related hedged items, bifurcated derivatives, and nonderivative instruments that are designated and qualify as hedging instruments. The updated guidance impacts only the Company's disclosure requirements and therefore will not have an impact on the Company's consolidated financial position or results of operations. The Company adopted this updated guidance and included the additional required disclosures. See Note 9—Fair Value Measurements, for disclosure of derivative instruments.

        In December 2007, the FASB issued updated guidance of ASC 810, "Consolidation." This updated guidance establishes accounting and reporting standards for ownership interests in subsidiaries held by parties other than the parent, the amount of consolidated net income attributable to the parent and to the noncontrolling interest, changes in a parent's ownership interest and the valuation of retained noncontrolling equity investments when a subsidiary is deconsolidated. The updated guidance also establishes reporting requirements that provide sufficient disclosures that clearly identify and distinguish between the interests of the parent and the interests of the noncontrolling owners. This updated guidance was effective for fiscal years beginning after December 15, 2008. The Company determined that this updated guidance has no impact on its consolidated financial position or results of operations.

3. Inventories

        Inventories are stated at the lower of standard cost (which approximates actual cost on the first-in, first-out method) or market and consisted of the following as of March 31, 2010 and 2009:

        The non-current portion of inventories represents that portion of the inventories in excess of amounts expected to be sold or used in the next twelve months.

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4. Property, Plant and Equipment

        Property, plant and equipment as of March 31, 2010 and 2009 consisted of the following:

        Depreciation expense for property, plant and equipment was $3.2 million, $2.7 million and $1.9 million for the years ended March 31, 2010, 2009 and 2008, respectively.

        During the three months ended September 30, 2009, the Company determined the depreciation of its leasehold improvements had changed from an original estimate of eight years to a revised estimate of 9.1 years because of the extension of lease terms for both manufacturing facilities located in Chatsworth and Van Nuys, California. This change in the estimated depreciation of the leasehold improvements resulted in a decrease in the annual depreciation from $1.3 million per year to $0.9 million per year in Fiscal 2010, a decrease from $0.8 million per year to $0.5 million per year in Fiscal 2011, an increase from $0.2 million per year to $0.5 million per year in Fiscal 2012, an increase from $23,000 per year to $0.4 million per year in Fiscal 2013, and an increase from $22,000 per year to $0.1 million per year in Fiscal 2014. The change in accounting estimate did not result in a change to net loss per common share for the year ended March 31, 2010.

5. Intangible Assets

        The Company's intangible assets consist of intangible assets acquired as a result of the acquisition of the TA100 microturbine generator product line (the "MPL") from CPS and an existing manufacturing license. See Note 14—Acquisition, for discussion of the MPL acquired from CPS.

        Intangible assets consisted of the following:

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