Vehicle-to-grid (V2G)

Vehicle-to-grid (V2G) is an innovative technology that allows the energy stored in an electric vehicle’s battery to be pushed back into the national grid or used to power your home (Vehicle-to-Home or V2H).

1. How V2G works

In a traditional setup, power only flows one way: from the grid into your car. With V2G, a bi-directional charger allows the flow to be reversed.

  1. Charging: You charge your car when electricity is cheap or solar generation is high.
  2. Storing: The car acts as a high-capacity home battery.
  3. Discharging: During peak times (when electricity is expensive), your car sends power back into your home or the grid, earning you money or reducing your bills.

2. Benefits of V2G

  • Financial Rewards: You can buy energy at 7p/kWh and sell it back during peak times for 40p/kWh or more.
  • Grid Support: V2G helps balance the grid by providing a massive, distributed source of storage that can be called upon during periods of high demand.
  • Home Backup: In the event of a power cut, your car could potentially power your entire home for several days (depending on your car’s battery size).
  • Sustainability: By making the grid more flexible, V2G allows for more wind and solar power to be integrated without needing fossil fuel backup plants.

3. Current Limitations

While the potential is huge, V2G is still in the early adoption phase in the UK:

  • Compatible Vehicles: Currently, only a few vehicles support bi-directional charging. Most use the CHAdeMO standard (like the Nissan Leaf). Most new EVs use the CCS standard, which is expected to support V2G fully by 2025.
  • Charger Cost: Bi-directional chargers are currently much more expensive than standard home wallboxes.
  • Battery Warranty: Some manufacturers have historically been concerned that frequent V2G usage could degrade the battery, though recent studies show the impact is minimal when managed correctly.

The Future: V2G is expected to become a standard feature of the UK’s energy system within the next decade. As millions of EVs are parked on driveways for 95% of the time, they represent a colossal energy resource that can help the UK reach Net Zero.

  • V2H (Vehicle-to-Home): Specifically using the car to power your own house, without necessarily sending power back to the wider grid.
  • V2L (Vehicle-to-Load): Allows you to plug standard 3-pin appliances directly into your car (e.g., for camping or powering tools). Common on cars like the Hyundai Ioniq 5 and Kia EV6.