In the early days of the electric vehicle rollout, drivers were told they could one day turn their cars into money-making machines by selling excess power they did not need.
The Vehicle to Grid charging, or V2G, was marketed as a way for consumers to mitigate rising energy bills by buying cheap energy during periods of low demand, then selling it back to the Grid – sometimes for a profit.
And while V2G is still in its trial phase, some motorists have claimed to have offset their energy bill entirely by beating energy companies at their own game.
Yet experts have warned that such schemes will not be within the reach of the average owner. Sam Greenbank, of battery analytics company Accure, said drivers hoping to reduce electricity bills must first be on a flexible tariff, such as those offered by Octopus and OVO Energy, at the time of use.
Mr Greenbank said: “The cost of electricity in the UK varies throughout the day and typically peaks at rush hour times.”
He also said drivers saving large amounts of money through V2G do not drive frequently, which allowed their cars to stay plugged in. He added: “It’s not unlike trading currencies but one where your computer won’t make exchanges if you’re not at your desk.”
Energy suppliers make a cut on trades made by drivers, meaning “a casual user would struggle to make significant money,” Mr Greenbank added. A recent trial by OVO paid drivers V2G owners for the energy sold back to the grid from their vehicle at a rate of 30p per kWh.
The technology needed to make use of V2G is also prohibitively expensive. V2G requires a “special charging box” containing a transformer that takes the electric current from the car and adapts it for the national grid.
These typically cost between £750 and “several thousand” depending on the supplier, Mr Greenbank said. It means even those making the highest amounts from V2G (around £70 a month) would need at least a year to make a profit from their electric car.