You can’t say when you pass one on the highway, but an electric car can be super powerful. It charges by plugging into the power grid, of course, but it can also send power into itself. With the increasing number of EVs, this vehicle-to-grid technologyor V2G, creates a revenue stream for drivers, who pay utilities to tap their batteries when grid demand increases.
Utilities across the country are pursuing pilot projects for the technology, figuring out how to coordinate hundreds, thousands and eventually millions of EVs. To that end, today a consortium of companies—Eversource, National Grid, EnergyHub, Sunrun, and Mobility House—is launching an early trial of the technology in Massachusetts so that utility customers can try it out. Lessons learned here and elsewhere can guide the approach to the mainstream, making the grid more reliable. and cheap electricityeven if you don’t own an EV. “It’s great to have Massachusetts leading the way here and doing this because this training is what will allow this technology to grow,” said Chip Silverman, director of grid services at Sunrun, a solar and battery company.
In the new system, participants log into an existing program called ConnectedSolutionswhich allows homes to run their residential batteries, among other things. Then when there is a “demand response” event, such as during a heat wave, EV batteries can help the grid continue. Members are compensated for this, just like some homeowners who generate energy from their own solar panels.
“It’s really kind of a small number of hours per year that you’re running the battery,” said Russell Vare, vice president of car-grid partnerships at Mobility House North America, a provider of infrastructure charging services. “It doesn’t have to be like discharge every day. It’s in those peak times that events are called.”
Services like V2G because they deal with increasing challenges. For one, the demand for electricity is growing as more power-hungry data centers come online and people switch from internal combustion vehicles to EVs and from gas furnaces to heat pumps. Meanwhile, utilities are trying to move away from gas and coal in favor of renewables like wind and solar. These clean technologies, though, are intermittent, since the wind doesn’t always blow and the sun doesn’t always shine. Utilities need ways to bank energy for later use, that’s why they exist storage buildings and even using the Earth itself as a giant battery.
Already, the Americans are are facing rising energy prices for various reasons. Corporation shareholders reap profits, for example, and customers foot the bill for improvements, such as burying power lines. so they don’t start wildfires or come down in a storm. Building battery facilities and transmission lines will add more costs—an inevitable price to pay for a cleaner, more reliable grid.
Unless some of those uses are unavoidable: V2G’s promise is that can make electricity cheaper. Although participants need a bidirectional charger to send power to the grid, the utility does not need to redesign the system as a whole. EV batteries are an existing, widespread and reliable source of backup power to tap into during times of peak demand, such as during the summer when everyone runs their air conditioner. “It’s the cheapest cost of energy storage that will be available to the national grid,” Vare said.
The warmer the planet, the more attractive V2G services become. People need extra AC to stay healthy, but appliances need a lot of power to operate. If that energy doesn’t come from renewables, it causes more heat and an increase in AC demand, on and on. In a V2G system, vehicles that follow predictable schedules, such as school buses and municipal fleets, will be particularly importantwith their batteries being large energy stores. Even a standard EV battery, though, has about six times the capacity of a backup unit installed outside the home.
