With California's electric system nearly maxed out during the state's worst-ever September heat wave, officials are asking residents to avoid using major appliances — or charging their electric vehicles — during peak demand to avoid rolling blackouts.

Reality check: EVs aren't what's straining the grid. California had roughly 680,000 registered EVs as of July 1, per S&P Global Mobility, accounting for less than 1% of the state's total electricity demand.

Why it matters: As more cars plug in, EVs could actually make the grid more resilient by supplying electricity back to the network when it's needed most.

Driving the news: This week's heat wave is testing the limits of California's power grid, and creating political headaches for Democratic Gov. Gavin Newsom, who plans to phase out the sale of gasoline vehicles by 2035.

The big question: How can the grid support even more EVs?

Where it stands: Many utilities commonly charge customers lower rates for electricity use during off-peak hours, which is helpful when charging an EV at home.

What's next: Vehicle-to-grid (V2G) technology takes that relationship even further, enabling utilities to draw power out of an EV when it's most needed. That's already working for school buses.

Yes, but: While V2G technology is promising, some carmakers are worried about protecting their standard eight-year, 100,000-mile warranty if the battery degrades faster than expected.

What to watch: Ford and GM are working with a number of utilities to explore how their vehicles — like the Ford F-150 Lightning pickup, which can power a house in a blackout — can supply electricity to make the grid more resilient.