Last week, California regulators approved a proposal that will require utilities to buy more clean power. Under the proposal, utilities will have to buy at least 11,500 megawatts (MW) of capacity from zero-emitting or renewable resources between 2023 and 2026, which is enough to power about 2.5 million homes, according to Reuters.

The order will allow the state to respond better to extreme weather events and replace capacity expected to be lost from the retirement of the Diablo Canyon nuclear plant in 2024-2025 and several natural gas plants in the middle of the decade. This is the largest capacity procurement ordered at a single time by the California Public Utilities Commission and the largest requiring only clean resources.

The latest proposal replaced earlier drafts that were opposed by environmental groups because the drafts called for utilities to buy up to 1,500 MW of capacity from fossil-fired generation. Natural gas is the primary fossil fuel used in California’s power market, along with the addition of intermittent, renewable wind and solar power in recent years.

Climate change is causing an extreme drought, record wildfires and heatwaves across the West and has also destabilized California’s electric grid. Last summer, utilities in the Golden State imposed rotating blackouts that left more than 400,000 homes and businesses without power for up to 2-1/2 hours when energy supplies ran short during a couple of hot days in August. That was just a sliver of California’s nearly 40 million people, but could happen again this summer as utilities increasingly rely on renewable sources of energy while the state seeks to phase out power from carbon-emitting fuels by 2045.