Optimist Daily: California’s first eight-hour grid battery now online

The California grid has a timing problem. Solar runs from mid-morning through early evening. Demand peaks later. Batteries have bridged part of that gap for years, but only about four hours’ worth. On June 1, a project in Kern County doubled that window. Tumbleweed, a 125-megawatt battery installation, went online as the first major storage facility in the U.S. capable of discharging for eight hours straight. It’s the only one of its kind in the country right now. Most grid batteries discharge for four hours at maximum capacity. That’s been the standard because it made economic sense: equipment costs and market conditions aligned around four-hour systems. But analysts have long argued that cost-effective 24/7 clean power requires longer-duration storage. California regulators reached the same conclusion in 2021 and ordered utilities to start procuring it. Learn MORE.