Vehicle to Grid - become a power station
The science behind this is a bit complicated, so we’ll keep it brief. Demand for electricity isn’t constant. As a nation, we use a lot in the late afternoon and evening and practically nothing in the middle of the night. Electricity is priced like any commodity, and rises and falls according to demand. A Megawatt Hour of power (the electric industry equivalent of a barrel of oil), costs your supplier more when you’re cooking your oven chips at 6pm than it does when you’re tucked up in bed.
So what’s this got to do with my Renault Zoe earning me enough cash for a holiday, we hear you ask. Well, to help balance the demand, electricity companies have developed a system called Vehicle to Grid, or V2G for short. Although it’s still in its infancy, the idea is that at times of peak demand (oven chips), your car will send power from its battery pack into the grid. This is a hugely attractive proposition to electricity suppliers, because your Zoe is cheaper to run than a nuclear power station and, apart from a different kind of meter, requires practically no infrastructure changes. In return for powering the nation, the electricity supplier will pay you a small amount for every unit of power you supply.
Obviously, you need to charge the car in the first place, and your delicate profit margin can only be realised if you’ve paid a lower amount to charge. As many electric car owners will already know, many suppliers offer a much cheaper ‘off-peak’ rate that can be a fraction of the usual peak rate. The reason why electricity is so much cheaper at night is that there’s very little demand (we’re all in bed) and generators such as wind farms keep on spinning regardless of whether the sun is up.
While V2G is still in its early stages in the UK, the system has already proven itself to be a viable way to balance the grid. Last year, Renault and electricity company We Drive Solar set up a V2G system on Porto Santo - a tiny island in the Atlantic. Solar panels charged up a fleet of Renault Zoe hire cars during the day. When islanders needed power in the evening, the system reversed the flow of power from the cars to the grid.
One electricity supplier – Octopus Energy – is already offering what it describes as a smart export tariff for owners of electric cars and battery storage systems. Its outgoing Octopus tariff pays customers 5.5 pence for every unit they export. If you used your own solar system to generate that power in the first place, that’s 5.5 pence profit.