California’s solar power record setting season is here


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, April 13, at 1:50 PM the California Independent System Operator (CAISO) reported instantaneous electricity generation of 11,011 MWac from solar power facilities connected to the transmission grid. If the 7.7 GWdc of behind the meter solar is running optimally, that would probably push total to at least 17 GWac of electricity generation coming from solar power.

The previously reported record by CAISO was set on 3/25 at just over 10.8 GW.

Just twenty minutes before that peak production moment, the CAISO region set a new electricity export record of 1,503 MW, which means that California was exporting a record amount of its solar-boosted mid-day electricity surplus, and reducing the need to curtail solar and wind. In following conversations of the below tweet, it has been observed that there is 10 GW of electricity transfer capacity out of California.

Of interest in the above tweet is the shape of the Renewables generation plot: it has “broad shoulders” – meaning production climbs to a peak, and then goes roughly straight for a long while, before dropping. Around 10 am the shoulders start to firm up, and they then run until 4 PM – 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 found that solar power availability was greater than 98% of projected time and that solar more often out performed projections than under performed.

Two other big spring time numbers have also been hit, the first being a record per CAISO with an “instantaneous maximum demand served by (utility) solar” on March 17, at 11 AM of 58.6% of all electricity usage. When adding in that prior noted approximate 7.7 GWdc / 6 GWac of behind the meter generation, the grid was running on around 69% sunshine.

And last, but actually most important (and noted in Friday’s pvMB) is that in another tweet, it was noted that on Wednesday, April 10th, at 11:05 am a full 93% of electricity generation in the ISO region was coming from zero carbon sources. Large hydro electric sources, plus nuclear were generating 25% of the state’s electricity. At this moment, the state was also exporting 412 MW of electricity, while burning zero coal. The only fossils burning were 1.55 GW of gas plants. 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 (remember the aforementioned broad shoulders) – California’s electricity generation was very similar to 11:05 AM and its 93% zero carbon electricity.