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.
Sure, but the majority of your energy is not renewable, plus you are emitting a lot of CO2. Heat pump for heating and electrical appliances would quickly rise your consumption to something like 30+kWh/day and then you’d have under three days of car battery. Also relying on car battery is tricky as in such case you can’t use your car and your car’s battery might be fairly empty when you need it.