New tech enables EV fleets to sell electricity to grid

For the first time, electric cars are feeding electricity to the grid and making money on it.

"It might be a few more years before a grid-integrated vehicle sits in every American driveway, but I'm excited to continue the journey," says Patrick Harker, University of Delaware President. 

The idea, originally conceived by Amory Lovins, is to enable EV owners to sell electricity to the grid from their batteries while they are parked during the day. That electricity will be used to stabilize the grid to counteract the intermittency of wind and solar.

Since late February, NRG Energy's eV2g technology has connected to the PJM Interconnection, which serves 60 million people in the 13 mid-Atlantic states. It's linked to PJM's frequency regulation market, which balances supply and demand on the grid second-by-second.             

In 2011, NRG joined with the University of Delaware to commercialize a two-way interface between electric cars and the power grid. In other words, it enables vehicle owners to sell electricity to the grid while they charge their cars.

eV2g allows EVs to communicate with the grid and lets grid operators take power from connected EVs during peak usage periods. EV owners can schedule in advance any times their vehicles need more charging than usual, as for a unusually long trip, and the minimum level of charge they want to maintain at all times. EV2g collects payment from the grid operator and pays EV owners for making their vehicles available. 

Importantly, the technology aggregates power from multiple electric vehicles to create one larger power resource, rather than individual, smaller ones. 

Photo of electric vehicle in car-sharing station by Viappy via

Next page: Early adopters will be commercial fleets