California invests big in battery energy storage — and leaves rolling blackouts behind

California successfully navigated the summer of 2025 without issuing a single "Flex Alert" or requiring rolling blackouts, marking a major achievement in grid reliability. This success is directly tied to the state's massive, rapid investment in utility-scale battery energy storage systems (BESS). These facilities store surplus renewable energy, particularly solar power generated during the day, and then discharge it during high-demand evening hours. By mitigating the evening power deficit—often called the 'duck curve' challenge—the deployment of storage appears to have solved the state's long-standing problem of summer power shortages. This milestone signals a crucial turning point in California's transition to a reliable, clean energy grid.