California had blackouts in 2020 when a heat wave meant there was insufficient power available as the sun went down and renewable sources shut down. Now California’s energy officials are predicting a repeat this summer if anything unexpected happens.

California energy officials on Friday issued a sober forecast for the state’s electrical grid, saying it lacks sufficient capacity to keep the lights on this summer and beyond if heatwaves, wildfires or other extreme events take their toll…

In an online briefing with reporters, the officials forecast a potential shortfall of 1,700 megawatts this year, a number that could go as high as 5,000 MW if the grid is taxed by multiple challenges that reduce available power while sending demand soaring, state officials said during an online briefing with reporters.

Supply gaps along those lines could leave between 1 million and 4 million people without power. Outages will only happen under extreme conditions, officials cautioned, and will depend in part on the success of conservation measures…

…many solar farms and energy storage projects the state has commissioned over the last two years were delayed due to supply chain challenges during the pandemic and a recent federal trade probe into solar imports.

The energy officials also predicted the energy shortfall would be slightly higher in 2025 (1,800 MW) than it is this year. Electricity prices are also expected to rise “between 4% and 9%” by 2025. California’s electricity prices are already some of the highest in the country. In February of this year, the state was in third place behind Hawaii and Connecticut (California’s average rates per kWh were tied with Massachusetts and Rhode Island at 25.59 cents, well above the national average of 13.83 cents).

Gov. Newsom clearly got a preview of this presentation because last week he announced the state was reconsidering its decision to shutter the last nuclear power plant in the next few years.

Newsom told the L.A. Times editorial board Thursday that the state would seek out a share of $6 billion in federal funds meant to rescue nuclear reactors facing closure, money the Biden administration announced this month. Diablo Canyon owner Pacific Gas & Electric is preparing to shutter the plant — which generated 6% of the state’s power last year — by 2025…

Nuclear plants are America’s largest source of climate-friendly power, generating 19% of the country’s electricity last year. That’s almost as much as solar panels, wind turbines, hydropower dams and all other zero-carbon energy sources combined.

Every summer, those of us who live here in California get “flex alert” announcements on the radio. These are basically warnings that unless people turn down their AC units we could face a blackout. They even have their own Twitter account.

A Flex Alert is a call for energy conservation to help relieve grid stress. Learn about the steps you can take to prepare and sign up for notifications at https://t.co/SvLoptiUH6 pic.twitter.com/vwbnxecjyX

— Flex Alert (@flexalert) May 3, 2022

The state clearly needs to preserve the Diablo Canyon plant and to add more natural gas generation and/or more battery storage. But all of that takes time. Fortunately, the state’s population is no longer growing (thanks in part to high prices for energy and everything else) so maybe that will give the state a chance to catch up with demand.