California runs on 100 per cent renewables, briefly, for first time ever

Less than two weeks after notching up a record 97.6% of instantaneous renewables on its grid, California has passed a major new milestone, with 100% of the state’s electricity supplied by renewable sources for a short period over the weekend.

According to the California Independent System Operator, the milestone was achieved within a 15 minute period between 2.45pm and 3pm on Saturday April 30, California time, marking the first time ever the massive state has been powered entirely by renewables.

Such levels have become common in smaller grids such as South Australia, but the milestone in California – one of the world’s biggest economies and biggest grids – is hugely significant.

As illustrated in the charts below, when state electricity demand passed 18GW at around 2.50pm, renewable energy was supplying around 18.6GW, compared to just over 2GW each from nuclear and gas, and a measly 9MW from coal.

At that time, the vast majority of the renewable energy supply was coming from California’s solar power resources, around 12.4GW, while another 4.7GW was being supplied by wind power. Geothermal, small hydro, biogas and biomass filled out the remainder.

The state has been edging towards the 100% milestone for weeks, hitting a previous high of 97.6% on April 03, which had in turn beat the previous record of 96.4 per cent set on March 27.

The milestone was celebrated on social media platforms including Twitter and LinkedIn as the first, but definitely not last time for a state that is shooting for 60% renewables by 2030 100% “carbon free” by 2045.

“Twenty years ago no one thought we could get to 100% renewable energy. But bit by bit, bill by bill, and solar panel by solar panel we did it,” said Dan Jacobson, a senior advisor to Environment California.

“This is a great day for California and the rest of the world. 100% clean energy is ready for prime time. The future is here today in California,” Jacobson said.

“California has shown that, for one brief and shining moment, we could do it!,” added Environment California’s state director Laura Deehan.

“Now we need to get our state running on 100% clean energy for the whole day, the whole week, and the whole year. It’s time to move to 100% clean energy, 100% of the time.”

The milestone comes as California debates the future of nuclear power in the state, with Governor Gavin Newsom under pressure to prolong the operating life of the state’s last remaining nuclear plant.

The state government has been planning since 2016 to replace the Diablo Canyon facility this decade with solar, battery storage and wind, but is considering applying for a federal grant to extend its life.

Meanwhile, the addition of new renewable capacity in the state is cracking on, with 600MW of solar and 200MW of wind scheduled to be added to the grid by the beginning of June, along with 1.3GW worth of new battery storage capacity, which is expected to grow from 2,700MW to 4,000MW by June 1.