What is vehicle-to-grid (V2G) charging and can it save me money?
V2G could help you save money and make the most of your EV’s capabilities; but is it worth the investment? Here’s your all-encompassing explainer...
Vehicle-to-grid (V2G) is a form of technology that allows your electric car to receive a charge in the normal way, or send unused energy back to the electricity grid during peak hours of demand.
It creates a two-way flow of electricity which, aside from helping to balance the electricity grid’s supply, means you could be paid for the grid to use the stored energy in your EV’s battery.
V2G is still a relatively new development, since most conventional home wallbox chargers only allow an EV to take energy from the grid (uni-directional), rather than providing the option to send it back to the grid (bi-directional). But with V2G growing in prominence, this guide is here to explain everything you need to know about it.
How does V2G work?
First, you’ll need a few things: a home smart meter, a compatible V2G charger and electric car, plus an energy supplier that provides a suitable home charging tariff.
Once installed, your dedicated two-way charger (often called a bi-directional charger) will communicate with your car and the smart meter – which has intelligent software pre-installed – to create an energy pathway between your car and the electricity grid. You can then use your smart meter to control how much electricity is being transferred, and when.
Is every electric car compatible with V2G?
Unfortunately not. Since the technology is still new, it requires advanced software and hardware to work, and this means only a handful of the latest electric cars have been built with V2G capabilities so far.
Examples of cars that currently support V2G are the Kia EV9 and the Nissan Leaf, while those that are going through compatibility tests include the Polestar 3, the Volkswagen ID.4 and the Volvo EX90.
The Nissan Ariya could take this one stage further, using an on-board charger which could reduce the overall cost of bi-directional charging.
Can I earn money by using V2G?
You certainly can, especially if you decide to activate V2G during peak hours. On weekdays in the UK, that’s usually between 8am and 11am, and then 4pm and 10pm. The amount of money you get varies depending on when and how much energy you’re sending.
Typically, you expect to earn between 5p and 15p per kWh sent. A recent trial by Octopus Energy found that users could end up saving up to £840 over a year, and one owner of the original Nissan Leaf is understood to be earning £2000 a year. Obviously this isn’t a fixed amount, and could vary substantially if/when V2G becomes mainstream.
Is V2G good for the environment?
It is indeed. Since V2G is effectively helping to recirculate renewable energy, reducing our reliance on fossil fuels and the amount of carbon emissions overall, it should lead to a negative carbon footprint over time.
With wider adoption, V2G could become an important part of the UK's energy infrastructure, with cars serving as battery storage from renewable energy sources.
Is there a limit to how much V2G charging I can do?
Yes, there are. Foremost are the restrictions imposed by your local electricity connection, which tend to hover between 3.68 kW to 7.36 kW per day. You may be capped by time limits to a set number of hours per day, and days per year, to protect the grid from overloading. And you may need to have your home's electricity equipment, and its connection out to the grid, upgraded.
You may also be restricted if you’re already exporting electricity from other sources, like solar panels. Ultimately, as V2G grows – and therefore the number of people that use it – so could the limitations imposed by decision makers.
Are there any other issues with using V2G?
Most significant is the implementation price: V2G chargers can cost anywhere from £3000 to over £6000, while traditional home chargers tend to cost from £1000 installed. It also means that if – for argument’s sake – you’re saving £500 a year from V2G, you’d need several years just to break even.
Of course, the cost of buying and installing a V2G charger is expected to come down if/when mass-production and adoption happens. But simultaneously, that could also impact the amount of money you’ll be earning from using it.
There is also an increased threat to cybersecurity. The interconnected network is large and still largely exposed, which could make it an easy target for online hackers. That potentially makes it vulnerable to power cuts and data leaks, or worse still, direct interference with the national grid itself. Admittedly, there are very slim chances of any of these things happening, but it’s best to still be in the know.
Is V2G the same as V2L?
They are not. Vehicle-to-load (V2L) is a technology some modern EVs have that allows them to power external devices directly, such as a laptop or a barbecue. Effectively, V2L is a means of turning your electric car into a big wireless charger, to be used in remote locations as and when needed, while V2G allows your EV to send electricity to the back to the grid.
Advantages of V2G:
- Potential earnings at peak demand times
- Helps stabilise the national grid’s supply
- Reduces our dependence on fossil fuels
- Contributes to a negative carbon footprint
Disadvantages of V2G:
- Implementation costs are high
- Use could be limited
- Profits could fall significantly over time
- Potential risk to cyber security
Should I use V2G?
While still in its infancy stages, and there are some obvious issues on the route to widespread adoption, we think V2G is worth using. If you have the means to, and your lifestyle permits, it could prove to be a residual money saver that contributes to a greener future.
Though the smart thing to do might be to wait for a little longer; until a wider selection of cars are compatible, and any potential teething issues are ironed out.
