(taxpayers invested in biodiesel plant and lost $400,000 when plant failed after only one month of operation; taxpayers claimed state (IA) investment tax credits; IA Dept. of Economic Development approved investment tax credit of $5.2 million via enterprise zone agreement with plant and county; agreement plainly stated that benefits not received if plant failed to comply with contract terms, including job creation and payment of wages; partnership owned plant and passed tax credits through to taxpayer who claimed credits on state return in two tax years after plant failed; IDOR sought repayment of credits from individuals ($42,000); IDOR entitled to seek repayment from individual taxpayers that received value of tax credit; (point of consideration for those interested in investing in such "renewable" technology - Congressional Research Service Report on biodiesel industry (No. 7-5700, R41631, Feb. 11, 2011)(report notes that biodiesel production would not exist if not for tax subsidies from U.S taxpayers; report notes that industry is inefficient and remains dependent on tax incentives and renewable fuels standard mandates)).