The shift to electric vehicles is seen as a necessary move as Earth faces the ever-growing impacts of climate change, but it could put a severe strain on infrastructure. Researchers from Stanford have published a study that claims the way most people charge their EVs is exactly the wrong way to do it for the future of the grid. They say if we don’t make changes, peak electricity demand could increase by 25 percent come 2035.
This new study, published September 22 in Nature Energy, is based on a separate one published earlier this year. In the first study, the team developed a model for charging demand that can be adapted to various population and environmental factors. Now, they’ve applied that model to the entire western United States. The analysis examines what will happen in the US if EV usage continues increasing at expected rates through 2035 — specifically, what will happen if everyone keeps charging their cars at night.
Most EV owners simply plug in their car after returning home, and some specifically program systems to hold off charging until later at night. That’s not entirely the fault of drivers, though. The traditional wisdom is that it’s better to charge at night when peak usage is lower, so power companies may offer discounted rates during those times. Not so, says the study.
Currently, California leads the way in EV adoption, with rates hitting six percent of all car sales earlier this year. When the rate reaches 30 or 40 percent, Stanford researchers say the power grid will come under extreme stress. As EV ownership increases, nighttime home charging will require more energy storage and generation capacity, while also wasting more solar and wind energy during the day.
The solution, according to the study, is to shift EV charging to workplaces and fast-charging stations that can be used during the day. The model predicts that as we reach 50 percent EVs on the road, these changes could make a significant impact. With no changes, more than 5.4 gigawatts of energy storage would be needed. If we can shift the bulk of that to daytime, we would need only 4.2 gigawatts of storage capacity.
It’s going to take changes in electricity pricing and infrastructure to make this work, but the study authors say it’s worth the effort. That’s particularly true if we need to shift more energy production to solar, which is useless at night unless there’s sufficient capacity to store it.