How will more electric cars affect California's grid?

More electric vehicles means more strain on the grid, but the state Energy Commission projects that they still will use a small fraction of California’s total electricity.

Peak hours
The grid is most stressed at peak hours — on hot summer evenings when demand is high and less solar energy is available. Based on the state's modeling for future years, officials expect
electric vehicles by 2035 will account for about 10% of the total system hour load — how much electricity utilities need to provide — during those peak times.
52k MW
0.8%
2022
4.7%
2030
10%
2035
Annually
​Annual consumption also is important to track. That's because rates that encourage charging during off-peak hours will mean that the percentage of total power that electric vehicles use annually will be considerably larger than the percentage for just peak hours. The state projects that
electric vehicles will account for almost 22% of baseline annual consumption by 2035.
342m MW
1.9%
2022
10.4%
2030
21.9%
2035
Graphic: Erica Yee, CalMatters
Notes about the data

These are not precise historical or predicted numbers, but general expected situations to help utilities know how much electricity they need.

Figures are for the CAISO regions, which account for about 80% of the state power grid.

Total load is less than total consumption because of “behind-the-meter” resources, namely rooftop solar: EV owners who use their own solar power to charge will consume more electricity than they need from their utility. The peak hour figures exclude behind-the-meter electricity, while annual consumption figures include it.

Source: Additional Transportation Electrification Scenario, Energy Commission