Your electric car spends most of its life parked. What if that big, expensive battery could earn its keep? That’s the idea behind vehicle-to-grid (V2G) charging. Your car becomes an extension of the wider power grid, and your battery is used to store and deploy energy when it makes the most sense.
Vehicle-to-grid (V2G) lets an electric car send electricity back to the power grid, not just draw from it. The car becomes a battery on wheels: it charges when demand and prices are low, then exports stored energy back at peak times, earning the owner credit for what it returns.
V2G is one branch of bidirectional charging, the broader family that also includes powering your home or a single appliance. We explain how they differ further down, and in more depth on the bidirectional charging page.
Vehicle-to-grid. Exports to the public grid for credit. Needs grid permission and a tariff.
Vehicle-to-load. Use your car to power anything you can plug in at home. The simplest, and the most available today.
You need three things:
Your battery stores DC electricity; the grid runs on AC. Charging converts grid AC to DC; V2G adds the reverse path, converting DC back to AC and feeding it in, precisely in step with the grid. Where that conversion happens is the one thing worth understanding:
AC bidirectional: the conversion happens inside the car. The wall charger stays simple and affordable. This is the route that takes V2G mainstream, and this is what all Zaptec chargers support.
DC bidirectional: the conversion happens in a larger, more expensive wall unit. More power, more cost.
ISO 15118 is the international standard that defines how an electric vehicle and a charger talk to each other. Its latest part, ISO 15118-20, adds the two-way communication that V2G charging depends on, letting a car both draw power and send it back to the grid. A V2G-ready charger needs to support it.
In the UK this is an interoperability standard, not a legal requirement. In the EU, the Alternative Fuels Infrastructure Regulation (AFIR), which comes into force in January 2027, specifically references ISO 15118-20. So, while there’s no legal requirement that a charger marketed as “V2G-ready” in the UK meets the industry standards, it’s likely that it will (especially if it’s also sold in the EU). All Zaptec chargers are ISO 15118-20-compliant.
We were the first V2G provider on the UK market, and we haven't stopped innovating since. Our Zaptec Go 2 installs in minutes, and is backed by a 5-year guarantee.
Yes, but it is early. After a decade of government-backed trials, the UK now has its first genuine commercial V2G products. Octopus Energy's Power Pack is billed as the country's first mass-market V2G tariff, and in June 2025 Octopus launched a bundle pairing a V2G-capable car with a bidirectional Zaptec Pro charger.
Compatible cars and certified chargers are still few, so for now V2G is an early-adopter proposition rather than the default. But the seed has been planted, and the direction of travel is clear.
You can earn or save with V2G, though the numbers today are modest and depend on your car, charger, tariff and how often you plug in. UK domestic trials put realistic savings at roughly £340 to £725 a year; commercial fleet trials landed around £700 to £1,250 per vehicle a year. Treat these as indicative trial figures, not a promise: your result depends on your setup.
Selling electricity back to the grid is the mechanism behind the headline. You charge cheaply, export at peak, and your energy supplier credits the difference.
If you're a business thinking about installing installing EV chargepoints, speak to our team today to discover how we can help, and what Government grants might be available to you.