The first involves California's Renewable Portfolio Standard" (RPS). First adopted in 2002, the RPS is part of California's effort to be a leader in combating climate change and is intended to give utilities the incentive to invest in solar, wind and geothermal power. The RPS has been modified several times since first adopted in 2002. Currently the RPS calls for 60% of electricity production to be renewable by 2030 and 100% to be renewable by 2045.
But what about nuclear power and hydropower? Where do they fit within the RPS? As always, the devil is in the details.
Nuclear has become a non-issue as California's last operation nuclear plant, Diablo Canyon, is expected to close in 2025 (Humboldt 3 closed in 1976, Rancho Seco closed in 1989 and San Onofre closed in 2013.)
Hydropower is a different story. In California, hydropower counts for 15-50% of total generation in most years. When the RPS was adopted, a political compromise decided that plants under 30 megawatts would count as renewable and those over 30 megawatts would not count as renewable.
So San Francisco's three facilities in the Tuolumne watershed (Kirkwood, Holm and Mocassin) are not presently considered renewable under the law. Nor is Don Pedro, downstream on the Tuolumne and operated by the Turlock and Modesto Irrigation Districts.