California Code, Public Utilities Code - PUC § 454.3

(a) The facility is designed to generate electricity from a renewable resource, including, but not limited to, solar energy, geothermal steam, wind, and hydroelectric power at new or existing dams;  the facility is subject to Resources Agency review of its environmental impacts and determination that the facility is environmentally acceptable;  its capital costs, when added to its costs of operation and maintenance, result in a cost of electricity generated over the useful life of the facility less than that of electricity generated by existing facilities utilizing nuclear power or fossil fuel;  and the facility is used and useful.

(b) The facility is capable of meeting the then applicable environmental pollution standards;  its capital costs, when added to its costs of operation and maintenance, result in a cost of electricity generated over the useful life of the facility less than that of electricity generated by existing facilities utilizing nuclear power or fossil fuel;  and the facility is used and useful.

(c) The facility is experimental and is, in the determination of the commission, reasonably designed to improve or perfect technology for the generation of electricity from renewable resources or to more efficiently utilize other resources in a manner which will decrease environmental pollution from and lower the costs of the electricity generated.