“Solar thermal powerplant” means a thermal powerplant in which 75 percent or more of the total energy output is from solar energy and the use of backup fuels, such as oil, natural gas, and coal, does not, in the aggregate, exceed 25 percent of the total energy input of the facility during any calendar year period.

(Added by Stats. 1988, Ch. 965, Sec. 2. Effective September 19, 1988.)