The University of Delaware and and an energy company are partnering to make commercially available technology that would allow electric vehicles to sell power back to the grid.

The university and NRG Energy are working together on the company and technology, to be called eV2g. University of Delaware professor Willett Kempton led development of the patented technology, a "vehicle-to-grid" system that the university said will allow parked and plugged-in electric vehicles to sell extra power that's stored in their batteries back to the grid when demand is high.

"This technology can be paid well, to provide the short bursts of back-and-forth power that we use to correct imbalances in the electric power grid," Kempton said in a news release from the university.  "In the future, this technology will be important for smoothing out the fluctuations in renewable energy production."

As communities consume more renewable energy, one problem is that sources such as wind power aren't constant. Relying on electric vehicles to even out the energy supply could be of help.

EV2g will collect payment from the grid operator and will pay electric vehicle owners for making their vehicles available when charging.

These "grid-integrated vehicles" could generate money for owners of electric vehicles and fleet managers, as well as lead to lower energy prices for consumers.

An NRG Energy official said eV2G is the first technology to offer a true two-way interface between electric vehicles and the electricity grid.