California’s solar power record setting season arrives


From pv magazine USA

Very soon, there is going to be a headline reading, “California just ran on 100% clean electricity” – and it could very well happen this spring. With that, as happens every spring time in California – we’re in record setting season!

On Saturday, at 1.50pm, the California Independent System Operator (CAISO) reported instantaneous electricity generation of 11,011 MWacfrom solar power facilities connected to the grid. If the 7.7 GWdc of behind the meter solar was running optimally, that would probably push the total to at least 17 GWac of electricity generation from solar at that point.

The previously reported record by CAISO was set on March 25, at just over 10.8 GW.

Just 20 minutes before that peak production moment, the CAISO region set a new electricity export record of 1,503 MW, which means California was exporting a record amount of its solar-boosted midday electricity surplus and reducing the need to curtail renewable power. It has been observed there is 10 GW of electricity transfer capacity out of California.

The shape of that renewables generation has “broad shoulders” – meaning production climbs to a peak then plateaus for a long while before dropping. At around 10am the shoulders start to firm up and they then run until 4pm – six straight hours of consistent renewable energy output without the need for batteries.

In a recent report by Fitch Ratings – Global Renewables Performance Review: Solar Outperforms Wind on a Global Scale – it was reported solar power availability was greater than 98% of projected time and that solar more often outperformed than under performed projections.

Two other big spring time numbers were also recorded, the first being a CAISO record with an “instantaneous maximum demand served by [utility] solar” on March 17, at 11am, of 58.6% of all electricity usage. When adding in the aforementioned 7.7 GWdc/6 GWac of approximate behind the meter generation, the grid was probably running on around 69% sunshine.

It was also noted that on Wednesday, April 10, at 11.05am, a full 93% of electricity generation in the ISO region came from zero carbon sources. Large hydroelectric sources plus nuclear were generating 25% of the state’s electricity. At that moment the state was also exporting 412 MW of electricity while burning no coal. The only fossil fuels burning were 1.55 GW of gas plant capacity. When looking at the numbers for the whole day on CAISO’s website, it becomes clear that for a very large portion of the day – broad shoulders, remember? –  California’s electricity generation was very similar to 11.05am and its 93% zero carbon electricity.

This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: