Vehicle-to-grid (V2G) refers to s system in which PHEVs or fully electric vehicles, connected to the power grid when not being used for transportation, could sell power to the electrical grid system.

A V2G system would require “smart” grid technology which would allow the electric utility to invite cars to begin feeding electricity back onto the grid during peak usage times. The premium prices offered for this energy during peak usage are thought to be high enough to quickly recoup the initial cost of installing the inverter system that would be required in the car (Ref. 4).

The advantage to the electric utility of having on demand access to thousands of kilowatt-hours stored in the batteries of vehicles is the potential for load balancing. Nuclear and coal power plants operate most efficiently when they are running at full capacity and are often producing more electricity then is demanded at off-peak times (ref. 1). Likewise, wind and solar electricity are generated during only a fraction of the day. The ability to store excess electricity that is generated during off-peak times and then extracting as needed during peak usage times when demand for electricity spikes, could postpone or eliminate the need for constructing and operating an additional power plant.