The owners of electric vehicles in Denmark have been earning up to $1,530 a year from utilities just by plugging in when they park and selling excess power back to grid when it is needed.
And a new study on this so-called vehicle to grid (V2G) strategy found that rather than degrading batteries, as some have feared, employing it can actually boost the batteries’ lifetime.
Because most cars are parked 90 to 95 percent of the time, electric vehicle (EV) researchers have long dreamed of deriving value from the excess capacity in the car battery. Plug-in cars “could charge up at night and feed voltage-regulation services or electric power back to the grid at peak power times during the day,” as EV expert Andrew Frank and I wrote in a 2006 Scientific American article.
Studies back then suggested the economic value of “grid services,” such as helping to balance supply and demand, might be able to significantly offset the cost of owning an EV. Plummeting battery prices and the EV revolution have now begun to make that dream a reality.
Nissan and Denmark’s largest utility (Enel) have been partnering on V2G trials as part of an effort to integrate more renewable energy sources into the grid, Bloomberg reports. Already EV owners have earned as much as $1,530 a year — more than a typical EV owner would pay for all of its charging during a year.
Here’s a video from Nissan on how the V2G technology works:
The future potential for EVs to help balance load — and to incorporate more variable renewables into the grid — is enormous. Bloomberg New Energy Finance projects that the electricity consumption from EVs will rise from 6 terawatt-hours today to 1,800 terawatt-hours in 2040, which is some 40 percent of current U.S. electricity demand.
In its latest analysis of the fast-moving EV revolution, BNEF’s advanced transport team “now estimates that EVs will account for 54 percent of all new light-duty vehicle sales globally by 2040, not the 35 percent share it forecast previously.” And this is without assuming any value from V2G.
As the new V2G study points out, “some authors have however dismissed V2G as economically unviable claiming the cost of battery degradation is larger than” any revenue that might be generated. The study, “on the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system” finds, however, that the reverse may actually be true: if the V2G is controlled by a “smart grid algorithm that is designed to minimize battery degradation.”
In that case, the authors concluded, “an EV connected to this smart-grid system can accommodate the demand of the power network with an increased share of clean renewable energy, but more profoundly that the smart grid is able to extend the life of the EV battery beyond the case in which there is no V2G.”
We are just at the beginning of the electric vehicle and battery revolution, and are only now learning what kind of synergies there will be between smart grid technology, batteries, EVs, and renewables. The future of transport is brighter — and greener — than ever.