The milestone, set on 30 April, was celebrated by environmental groups. “California busts past 100% on this historic day for clean energy!” tweeted Dan Jacobson, co-founder of the activist thinktank EcoEquity.
Daniel M Kammen, a professor of energy at UC Berkeley, also wrote: “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.”
According to the tracker app from the California Independent System Operator (CAISO), which oversees the state’s power grid, energy demand reached 18,672 megawatts(MW) mid-afternoon on Saturday, with 37,172 MW available.
The record was held for nearly 15 minutes, then dropped to 97 per cent of clean energy output, The Desert Sun reported.
Solar power makes up the majority of California’s renewables followed by wind energy then to a lesser extent, geothermal, biomass, biogas and small hydro.
The state of California, the world’s fifth largest economy, produces more renewable energy than any other US state, helped along by its near year-round sunshine.
Governor Gavin Newsom’s budget proposal for next year includes around $2bn to boost the transition to 100 per cent electricity. California has set a goal of achieving 100 per cent clean electricity by 2045.
President Joe Biden’s has pledged to decarbonize the US power grid by 2035 but some analysts have said the country will struggle to meet that goal.
Some 59 per cent of the state’s electricity came from renewable and zero-carbon sources in 2020, according to the latest data from the California Energy Commission.
In 2019, over 60 per cent came from renewable and zero-carbon sources. Last year’s drop was due to less hydroelectric generation caused by the severe drought impacting much of the state, along with delays to new clean energy operations caused by the pandemic.