As California rapidly boosts sales of electric cars and trucks over the next decade, the answer to a critical question remains uncertain: Will there be enough electricity to power them?
State officials claim that the 12.5 million electric vehicles expected on California’s roads in 2035 will not strain the grid. But their confidence that the state can avoid brownouts relies on a best-case — some say unrealistic — scenario: massive and rapid construction of offshore wind and solar farms, and drivers charging their cars in off-peak hours.
Under a groundbreaking new state regulation, 35% of new 2026 car models sold in California must be zero-emissions, ramping up to 100% in 2035. Powering these vehicles and electrifying other sectors of the economy means the state must triple its power generation capacity and deploy new solar and wind energy at almost five times the pace of the past decade.
The Air Resources Board enacted the mandate last August — and just six days later, California’s power grid was so taxed by heat waves that an unprecedented, 10-day emergency alert warned residents to cut electricity use or face outages. The juxtaposition of the mandate and the grid crisis sparked widespread skepticism: How can the state require Californians to buy electric cars if the grid couldn’t even supply enough power to make it through the summer?
At the same time as electrifying cars and trucks, California must, under state law, shift all of its power to renewables by 2045. Adding even more pressure, the state’s last nuclear power plant, Diablo Canyon, is slated to shut down in 2030.
With 15 times more electric cars expected on California’s roads by 2035, the amount of power they consume will grow exponentially. But the California Energy Commission says it will remain a small fraction of all the power used during peak hours — jumping from 1% in 2022 to 5% in 2030 and 10% in 2035.
“We have confidence now” that electricity will meet future demand “and we’re able to plan for it,” said Quentin Gee, a California Energy Commission supervisor who forecasts transportation energy demand.
But in setting those projections, the state agencies responsible for providing electricity — the California Energy Commission, the California Independent System Operator and the California Public Utilities Commission — and utility companies are relying on multiple assumptions that are highly uncertain.
“We’re going to have to expand the grid at a radically much faster rate,” said David Victor, a professor and co-director of the Deep Decarbonization Initiative at UC San Diego. “This is plausible if the right policies are in place, but it’s not guaranteed. It’s best-case.”
Yet the Energy Commission has not yet developed such policies or plans, drawing intense criticism from energy experts and legislators. Failing to provide enough power quickly enough could jeopardize California’s clean-car mandate — thwarting its efforts to combat climate change and clean up its smoggy air.
“We are not yet on track. If we just take a laissez-faire approach with the market, then we will not get there,” said Sascha von Meier, a retired UC Berkeley electrical engineering professor who specializes in power grids. The state, she said, is moving too slowly to fix the obstacles in siting new clean energy plants and transmission lines. “Planning and permitting is very urgent,” she said.
The twin goals of ramping up zero-emission vehicle sales and achieving a carbon-free future can only be accomplished, Victor said, if several factors align: Drivers must avoid charging cars during evening hours when less solar energy is available. More than a million new charging stations must be operating. And offshore wind farms — non-existent in California today — must rapidly crank out a lot of energy.
To provide enough electricity to meet total demand, California must:
- Convince drivers to charge their cars during off-peak hours: With new discounted rates, utilities are urging residents to avoid charging their cars between 4 p.m. and 9 p.m. But many people don’t have unrestricted access to chargers at their jobs or homes.
- Build solar and wind at an unprecedented pace: Shifting to all renewables requires at least 6 gigawatts of new resources a year for the next 25 years — a pace that’s never been met before.
- Develop a giant new industry: State officials predict that offshore wind farms will provide enough power for about 1.5 million homes by 2030 and 25 million homes by 2045. But no such projects are in the works yet. Planning them, obtaining an array of permits and construction could take at least seven to eight years.
- Build 15 times more public chargers: About 1.2 million chargers will be needed for the 8 million electric cars expected in California by 2030. Currently, about 80,000 public chargers operate statewide, with another estimated 17,000 on the way, according to state data.
- Expand vehicle-to-grid technology: State officials hope electric cars will send energy back to the grid when electricity is in high demand, but the technology is new and has not been tested in electric cars.
- Increase electricity production by up to 42% in 2035 and, under a recent scenario, as much as 85% in 2045, according to California Energy Commission estimates. Generation capacity — the maximum that must be installed to meet demand throughout a given year — would need to triple by 2045.
Day and night charging
Climate change has already stressed California’s energy grid, especially during hot summer months when residents crank up air conditioners in the late afternoon and early evening.
Providing electricity during those hot summer evenings — when people use the most — will be a challenge, said Gee of the California Energy Commission.
“That’s what we’re particularly concerned about,” he said. “We have enough electricity to support consumption the vast majority of the time. It’s when we have those peak hours during those tough months.”
The total electricity consumed by Californians is expected to surge by 96% between 2020 and 2045, while net demand during peak hours is projected to increase 60%, according to a study commissioned by San Diego Gas & Electric.
Southern California Edison worries that if drivers charge during late summer afternoons, electric vehicles could strain the grid, said Brian Stonerock, the utility’s director of business planning and technology. Edison’s service area includes the desert, where customers rely on air conditioning, and their peak use times are when solar power is less available as the sun goes down.
Concerns about the grid “are quite a big deal for us,” he said. “We don’t want people to be confused or lose confidence that the utility is going to be able to meet their needs.”
But for many drivers, charging during the day or late at night is not a problem: Most electric cars have chargers that can be automatically turned on after 9 p.m. But for some drivers, especially those who live in apartments or condominiums, charging during those hours may not be an option.
That’s because — unlike filling a gas tank — charging an electric car takes much longer. Drivers may not have a reliable place to park their cars for long periods of time during the day while they work or late at night when they’re home. To encourage daytime charging, Victor said the state must drastically boost the number of fast chargers and workplace stations.