The period occured in 2024 between late winter and early summer. “Compared to the same period in 2023, solar output in California is up 31%, wind power is up 8%, and batteries are up a staggering 105%.”
Link to the study PDF mentioned in the article: https://web.stanford.edu/group/efmh/jacobson/Articles/Others/25-CaliforniaWWS.pdf
One of the paper’s cowriters is Mark Z. Jacobson, professor of civil and environmental engineering and director of the atmosphere/energy program at Stanford University.
I learned that “batteries” can literally took many form, some use molten salt, some use gravity, some use water, and some use the battery we all know. Am actually kinda curious on what works for them, but since it isn’t really 100% consecutively it doesn’t matter in this case.
PG&e owns two massive water reservoirs in the Sierra Nevada Central region called courtright and wishon. They funnel water up and down a steep gradient between shaver lake and the reservoirs to control peak energy demand. It’s actually a really effective and mostly efficient system, especially when rain and snow refill the upper reservoirs.