“Every month we’re seeing thousands and thousands more electric vehicles coming online,” Nick Morelli, an analyst and decarbonization strategist with Pacific Gas and Electric (PG&E), one of the largest utilities in California.
There are some 477,000 EVs in the PG&E service area, which is about one of every seven EVs adopted across the nation.
“The convenience and flexibility of electric vehicle charging actually provides a great opportunity to improve grid resilience,” said Morelli, echoing a common observation among utility officials who note EVs’ ability to charge during non-peak times, as well as the growing prevalence of energy storage, able to offload power when the grid is feeling stressed.
“EVs are flexible load. And because they are flexible load, they have the ability to improve grid resilience,” said Chanel Parson, director of electrification at Southern California Edison, another of the large California electric utilities.
Parson and Morelli joined other electric utilities officials for a forum discussion around grid resilience in an age of increasing EV adoption. The July 24 discussion was organized by the Zero Emission Transportation Association (ZETA), an EV policy and advocacy group.
Estimates suggest the U.S. will need an additional 15 to 27 terawatt hours of electricity by 2050, to power electric vehicles, which is about 0.5 percent of current capacity, said Albert Gore, executive director of ZETA.
“There’s a lot of misinformation at the outset about how we’re going to meet the growing energy demands associated with widespread EV adoption,” said Gore.
Electric utility and other officials point out the typical light-duty passenger vehicle is on the road only about five percent to 10 percent of the day, leaving up to 23 hours of the day where the vehicle can recharge, said Parson.
“And that’s a lot of flexibility,” she remarked.
Happening alongside EV adoption is the greening of the electric grid, as utilities continue to add renewable power, largely in the form of solar and wind.
Renewable energy is expected to provide 18 percent of the world’s power by 2030, said Emily Stipe, senior manager of federal advocacy at Vistra Energy, a Texas-based utility. Non-hydroelectric renewable energy provided about 35 percent of California’s electricity, as of 2021. But these are often intermittent resources, said Stipe, adding that there will be a need for “accompanying technology” to provide the necessary reliability.
Vistra operates the Moss Landing Energy Storage Facility in California, the largest energy storage facility in the world. Vistra has completed an expansion of the facility, bringing its total storage capacity to 750 megawatts.
Demand growth as well as severe weather events have strained the California grid, such as the September 2022 heat wave.
“During that event battery ended up providing about four percent of electric supply,” said Stipe — enough to avert rolling blackouts in the state.
Battery storage is moderating demands on the grid and increasing reliability, say industry experts.
“As the energy supply mix continues to become more tilted toward low and zero-carbon resources, energy storage is going to be the technology that helps ensure that the grid remains reliable,” said Stipe.
Consequently, energy storage can also be applied to EV charging stations where it can be used to manage peak demand, and reduce “grid congestion” on transmission lines. Because even a four-plug, high-speed charging station delivering 150 killowatts per charger can pull enough power to supply hundreds of homes. This is where some of the challenges around energy capacity and supply could originate.
For example, when a new neighborhood is planned, it could take years before the project is designed, built and fully occupied, giving utilities the adequate lead time to build out the needed infrastructure. But in the case of vehicle charging stations, these can be constructed in months rather than years, and require full energization. It’s why PG&E and other large utilities — particularly in California — have been proactively planning where high-speed charging will be needed, said Morelli.
“With public charging and fleet electrification, which typically resulted in much larger load requests, we were mostly reliant on customer applications for service to inform where this additional capacity was needed,” he explained. “And the difficulty there was the speed at which these large EV charging stations can be constructed was much faster than the time that it typically takes to reactively design and build capacity for these services.”