California hit a clean energy milestone last weekend when the state’s renewable power sources like solar and wind generated essentially as much electricity as the state needed.
The record occurred shortly before 3 p.m. on Saturday, as solar power production soared but before late-afternoon power demand kicked in.
“California achieved 100% renewable energy today. Very clear we can achieve clean energy everyday before 2030 if we cut the fossil fuel subsidies and political inertia,” Daniel Kammen, an energy professor at UC Berkeley, wrote on Twitter.
Experts cautioned the statistic is imperfect as it leaves out residential rooftop solar and also doesn’t account for how much energy is lost during transmission of the power from where it is produced to where it is used. The California Independent System Operator, which manages the state’s grid, said that the share of renewable energy peaked at 99.87% — marking a record for the state, albeit a fleeing one.
In addition, a brief time period does not reflect the overall electricity picture in California. Spring is a time of relatively low power demand, because moderate temperatures outside mean less need for heating or cooling, and longer days bring high solar power production.
Huge solar farms like this one, a nearly 750,000-panel array near Santa Margarita (San Luis Obispo County), have helped power California to new records of renewable energy production.
Michael Macor/The Chronicle 2015
Californians still rely heavily on natural gas throughout the year. Natural gas provided 37% of energy in the state in 2020 — more than the 33% of all renewable energy sources combined, the latest data from the California Energy Commission. Solar power provided 13% and wind 11% of the state’s electricity.
Still, clean power advocates viewed Saturday’s milestone as brief but stunning proof of the energy shift made over the last several decades. California must get 100% of its electricity from carbon-free sources by 2045 if it is to meet a goal signed into law nearly four years ago by then-Gov. Jerry Brown.
“It wasn’t all day, it wasn’t all weekend and we have a long way to go before we’re not burning fossil fuels — but we definitely can get there,” said Laura Deehan, state director with Environment California, a nonprofit renewable energy advocacy group.
The state has tripled its use of renewable power sources over the last ten years, mostly with new wind and solar projects. Other renewable energy sources include geothermal, biomass from wood products and biogas from food scraps and animal waste. Although nuclear is a carbon-free energy source, it is not included in the electric grid operator’s renewable energy calculator. Nor is power produced by large dams, which are …….