Credits established by the federal and state government to assist the development of the alternative energy industry. Beginning in 1976, California had a solar tax credit. From 1978 to 1985, both California and the federal government offered tax credits for alternative energy equipment. The state provided a 55 percent tax credit on solar, wind, geothermal and biomass for residential applications. However, the residential tax credits were reduced by applicable federal credits. State commercial tax credits for alternative energy systems in commercial and industrial sectors ranged from 10-15 percent. During this same time, the federal government offered a 40 percent tax credit on residential applications and a 10-15 percent credit on commercial and industrial applications. California in 1990 instituted a new 10 percent tax credit for commercial solar systems in excess of 30 watts of electricity per device. This credit expired December 31, 1993.