Public Resources Code § 25120

“Thermal powerplant” means any stationary or floating electrical generating facility using any source of thermal energy, with a generating capacity of 50 megawatts or more, and any facilities appurtenant thereto. Exploratory, development, and production wells, resource transmission lines, and other related facilities used in connection with a geothermal exploratory project or a geothermal field development project are not appurtenant facilities for the purposes of this division.

“Thermal powerplant” does not include any wind, hydroelectric, or solar photovoltaic electrical generating facility.