Solar power has grown to enormous levels in California, and that solar power is keeping wholesale prices low. Wind power, water power, and solar power all mean free fuel, and free fuel means low wholesale electricity prices. This is not news, but given how much people love to exclaim “California is expensive,” it did shock me to find out that wholesale electricity is cheaper in California — technically, the California ISO (CAISO) grid — than anywhere else in the country.
That news comes to us via Mark Z. Jacobson, Stanford University Professor of Civil and Environmental Engineering, and Director of the Atmosphere/Energy Program at Stanford. “CAISO had the lowest U.S. wholesale electricity prices 2025-26, indicating most stable grid. No blackout since 2020,” Jacobson shared on BlueSky.
That was actually the second part of his post, not even the top highlight. “59 straight and 125 of 149 (84%) days in 2026 with WindWaterSolar meeting >100% of demand on the California ISO grid for an avg of 4.9 h/d among all 149 days,” he shared first. In another format, here are those points:
- Wind, water, and solar power have provided at least 100% of the California ISO grid’s electricity demand for an average of 4.9 hours a day so far this year. (Expect that to get better in the coming sunnier months.)
- In 125 out of 149 days — and 59 days in a row — wind, water, and solar (WWS) power reached more than 100% of electricity demand at some point in the day.
Jacobson also shared the following graphs:
He also linked to this US Energy Information Administration page, where you can see information on wholesale electricity prices, among many other things.
So, yeah, big wins for clean, renewable energy in California. The state may have high retail electricity prices for other reasons, but the abundance of cheap wholesale electricity from sunshine, wind, and water is not one of them!
59 straight and 125 of 149 (84%) days in 2026 with WindWaterSolar meeting >100% of demand on the California ISO grid for an avg of 4.9 h/d among all 149 days.CAISO had the lowest U.S. wholesale electricity prices 2025-26, indicating most stable grid. No blackout since 2020eia.gov/electricity/…
— Mark Z. Jacobson (@mzjacobson.bsky.social) 2026-05-30T15:47:05.647Z