14. Other Current Liabilities

        In September 2007, the Company entered into a Development and License Agreement (the "Development Agreement") with UTC Power Corporation ("UTCP"), a division of United Technologies Corporation. The Development Agreement engaged UTCP to fund and support the Company's continued development and commercialization of the Company's 200 kilowatt ("C200") microturbine. Pursuant to the terms of the Development Agreement, UTCP contributed $12.0 million in cash and approximately $800,000 of in-kind services toward the Company's efforts to develop the C200. In return, the Company agreed to pay to UTCP an ongoing royalty of 10% of the sales price of the C200 sold to customers other than UTCP until the aggregate of UTCP's cash and in-kind services investment had been recovered and, thereafter, the royalty would be reduced to 5% of the sales price. In August 2009, the Development Agreement was assigned by UTCP to Carrier Corporation ("Carrier").

        On January 14, 2011, the Company entered into an amendment to the Development Agreement with Carrier. The amendment amends the royalty payment from a certain percentage of the sales prices to a predetermined fixed rate for each microturbine system covered by the amendment. Carrier earned $4.3 million, $3.2 million and $1.9 million in royalties for C200 and C1000 Series system sales during the year ended March 31, 2013, 2012 and 2011, respectively. Earned royalties of $1.4 million and $1.0 million were unpaid as of March 31, 2013 and March 31, 2012, respectively, and are included in accrued expenses in the accompanying balance sheets.