California just hit an inflection point for batteries

A few days ago, the electric grid in California hit a new milestone: At 7pm on March 29, batteries provided 12.3 gigawatts of power—roughly as much as six Hoover Dams, or around 43% of the total demand on the grid. Nearly all of that battery storage was built in the last five years. “Until 2020 or 2021, battery storage was still quite expensive, but we’ve seen huge price drops over the last few years,” says Nicolas Fulghum, senior energy and climate data analyst at Ember, a global energy think tank. When it’s paired with solar power, it can “bring some of that excess generation in the middle of the day to where it’s really needed, which is during the peak demand in the evening and morning,” he says. The cost of batteries has dropped 99% over the last three decades. Over the last few years alone, the cost fell by about a third. The cost of solar panels has also fallen by more than 90%. By 2024, new solar projects were an average of 41% cheaper than fossil fuel alternatives. By using bat