California needs to charge electric vehicles during day, not night, to save grid, study says
California can save itself from grid failure and carbon emissions by getting rid of a night-time charging system, a new University of California, Berkeley, study concludes.
Researchers surveyed 30,000 Californians about their daily energy use and found, for the first time, clear-cut evidence that electric vehicle drivers were using electricity at night during the day.
They concluded that if the state’s grid were to be forced to respond immediately to the new drivers’ demand for power, the resulting disruption could last nearly as long as five years.
The study was published Thursday in the journal Nature Climate Change.
“The fact is that California is already a large carbon emitter and the state’s infrastructure is aging,” the study’s lead author, UC Berkeley climate scientist Katharine Hayhoe, said in an email. “We can’t afford to go on this kind of a crash course.”
The study said California’s electricity system has an advantage over other states because its daily electricity demand peaks at 1 p.m., when many vehicle drivers charge their vehicles, then declines sharply in the evening.
The study found that nearly a quarter of California’s grid had been deactivated in the previous seven years.
“I was concerned that we might be looking at a grid that had been degraded or crippled and that would have to be rebuilt,” said UC Berkeley’s John B. Good, an author of the study. “But, if you consider that the state’s electricity use is in the order of a tenth of its gross domestic product, that would take a lot of money.
“It’s an opportunity to take the pressure off, and we can use it to reduce or eliminate air pollution.”
UC Berkeley researcher Katharine Hayhoe holds up a map at a news conference about the study released Thursday, April 24, 2018 on the campus of UC Berkeley.
Electric drive vs. plug-in hybrid
The study examined how people in the state used electricity on a day-by-day basis, from sunrise to midnight.
The researchers said they found that electric vehicle drivers were nearly as likely as plug-in hybrid drivers to use electricity at