new study conducted by a team at Stanford University and published in Energy Nature found that the increasing number of electric vehicle owners across the western United States could significantly impact the costs of, and demand for, electricity.

Many EV owners charge their vehicles at home overnight. The low demand during these hours means costs are usually lower. However, the study shows that as more drivers switch to EVs, that could change. The study found that peak net electricity demand could increase by up to 25% by 2035, the same year California said it would ban the sale of new gas-powered cars and trucks.

The group also conducted a “stress test,” which found that the demand could rise as much as 50% if every vehicle on the road is a plug-in model. 

Authors of the study suggest electric vehicle owners start to charge their vehicles during the daytime hours whenever possible, such as during the workday or at public charging stations. The study says that daytime charging will become even more important as wind and solar energy sources become more prominent.

“In the future grid with higher renewable generation, timing is more important and net demand tells a very different story than total demand,” the study reads. “Shifting drivers from home to daytime charging improves all metrics of grid impact including ramping, use of non-fossil fuel generation, storage requirements, and emissions. This insight is robust across varying levels of EV adoption.”

Charging EVs overnight might get a lot more expensive, says Stanford study