Electric cars are to be plugged into a new system that allows the National Grid to use them as batteries - draining their power when there is high demand from other users or low supply from green-energy power stations.
Electric cars could also be used to store excess electricity at times of high production.
A trial of the technology will be run between April and June with the potential for a national roll-out if it works, reports The Telegraph.
Cars could be used to top up the supply for nearby users if, for example, wind farms are temporarily unable to satisfy demand.
The scheme is being run by Octopus Energy, which has recruited 135 households.
Claire Miller, director of technology and innovation at Octopus, told The Telegraph: “This will demonstrate how you can send a signal from the National Grid control room to those vehicles and contribute to balancing the grid at times when it needs a bit more electricity, for instance at tea time when there is a lot of demand.
“Conversely, on a windy night when our wind turbines are generating electricity, we might also need a place to put energy.
“What we're doing is the first step on that journey. We are showing the energy industry what is possible.”
In a different scheme a small number of households already sell surplus power from their vehicles' batteries back to the grid.
Julian Leslie, chief engineer at the network operator National Grid ESO, said: “If we can get 10 million vehicles doing vehicle-to-grid, then fantastic.”
One million electric cars could provide roughly the same as 5,000 onshore wind turbines.
Participants in the Octopus trial are being paid 15p per kilowatt hour for the electricity they send to the grid, or 60p per hour.
