Vehicle-to-grid (V2G) charging explained
What is V2G charging and how does it work?
V2G charging allows EVs to draw power from the grid and send energy back into it, helping balance supply and demand. The process relies on a V2G-compatible charger and a vehicle with the right hardware.
Some energy suppliers may provide apps to do this, or integrate with your home energy system to monitor and manage your energy use. These systems ensure your EV charges when energy is cheap and feeds energy back when it’s needed, benefiting both you and the grid.
What are the benefits of V2G charging?
V2G charging offers several key benefits:
- Financial - it lets you earn money or reduce your energy bills by selling excess power back to the grid
- Environmental - it helps stabilise the grid - especially during periods when renewable energy sources are less reliable - and reduces overall carbon emissions
- Practical - it turns your EV into a power source for your home, providing an introduction to vehicle-to-home (V2H) charging, which is similar to V2G but focuses on supplying power to your home instead of the grid.
V2G and time-of-use tariffs: a perfect match
Time-of-use (TOU) tariffs charge less for electricity during off-peak hours. This makes it cheaper to charge your EV when demand is low. With V2G, you can also sell electricity back to the grid during peak times, when rates are higher.
Smart charging strategies like charging during off-peak times, selling power back during peak hours, or setting specific charge/discharge times help you access the lowest rates and boost the potential profit of V2G charging.
Is V2G available in the UK?
Several suppliers - including Octopus Energy - offer V2G schemes in the UK as part of trials and partnerships with companies like UK Power Network (UKPN), Nissan and Indra Renewable Technologies.
To use V2G, you need a smart meter, a compatible V2G charger and a car that supports the technology.
Which cars and chargers support V2G?
Common V2G-ready vehicles include the Nissan Leaf and VW ID Buzz. Most V2G systems use a specific type of charger connector called CHAdeMO, but some models can also use CCS, which is another type of connector.
Smart V2G chargers such as the Wallbox Quasar 1 and Indra V2G units enable bidirectional energy flow, allowing your EV to both charge and discharge to the grid. Installation costs vary but generally range from £500 to £1,000, depending on your home’s specific requirements.
What are the downsides of V2G?
Like all things in life, for every upside V2G offers, there are downsides to consider:
- Battery degradation: There are concerns that frequent charging and discharging could shorten EV battery life. However, the impact should be relatively minimal when using V2G within recommended guidelines and following battery health management recommendations
- High upfront costs: V2G chargers and installation can cost up to £6,000, which may be too expensive for some budgets
- Limited availability: V2G is still not widely available, with eligibility requirements such as having a compatible car, charger and smart meter making it even trickier for some.
How much money could you make?
Earnings from V2G depend on how much energy you return to the grid during peak times. You could earn between 5p and 15p per kWh, depending on your supplier and the demand, though this isn’t an amount set in stone.
Octopus Energy’s Powerloop trial suggests participants could save up to £180 per year compared to standard smart charging on a TOU tariff, or up to £840 per year compared to unmanaged charging on a flat tariff, assuming an annual mileage of 10,000 miles.
By optimising TOU tariffs, you can further increase earnings. For instance, charging your EV during off-peak times and discharging during peak hours can increase profitability, as peak-time rates are much higher.
Getting started with V2G
To start with V2G you need:
- a compatible EV
- a smart V2G charger
- a supplier that offers a suitable tariff
- an EV that supports the tech.
The setup and installation costs for a V2G charger can cost up to £6,000, and installation fees generally range from £500 to £1,000.
Support for early adopters is available through suppliers like Octopus Energy, which offer V2G trials.
FAQs
Can I use my EV to power my house in the UK?
Yes, it is possible to use an EV to power your home in the UK, provided the EV and your home charging setup are compatible with bidirectional charging. Known as vehicle-to-home (V2H), it can provide backup power from your EV to your home during power outages and support off-grid setups. However, V2H is currently limited to certain EV models and compatible chargers.
What is the difference between V2G and V2H?
V2G sends energy from your EV back to the grid, while V2H powers your home directly. V2G requires specific grid infrastructure, while V2H typically serves as backup power. Availability in the UK depends on compatible EVs, chargers and energy suppliers.
What is the Octopus V2G tariff?
The Octopus Power Pack enables EVs to charge during off-peak hours and discharge excess energy back to the grid when demand is high. This process helps balance the grid and allows EV owners to earn money. You can apply through the Octopus Energy website.
Will V2G damage my EV battery?
Early research shows that V2G can impact battery life, though proper usage within recommended guidelines should prevent significant wear. Minimise damage by avoiding frequent battery drain and optimising your vehicle’s battery management system for V2G. Regular monitoring can also help protect the battery.
Is V2G charging worth it?
V2G charging can be worth it if the income from selling electricity back to the grid outweighs setup costs, which can be upwards of £6,000. Ideal users are those with compatible EVs, a suitable charging system and access to TOU tariffs who can maximise off-peak charging.
Do I need a smart meter for V2G?
Yes, a smart meter is essential for V2G as it provides real-time data on energy usage and enables precise control of when to charge and discharge. The smart meter should also be compatible with V2G systems, such as those provided by suppliers like Octopus Energy.
Can V2G help the environment?
Yes, V2G helps the environment by balancing the grid and supporting renewable energy sources. By storing excess renewable energy and discharging it during peak demand, V2G reduces reliance on fossil fuels, helping lower carbon emissions and improve overall energy efficiency.
How do I sign up for a V2G trial?
To join a V2G trial in the UK, identify active programs such as the Electric Nation Vehicle to Grid Project or Octopus Power Pack trials. These trials often require specific EV models, compatible chargers and may involve a selection process. Application processes typically include online registration, eligibility verification and coordination with installers and energy suppliers.
