CARS spend 90 per cent of the time parked. Now with the right technology, the stored energy in the battery of a parked EV can become a useful resource.

The potential of this technology was shown in 2011, when a fleet of electric Nissan Leafs contributed to the relief effort after the earthquake and tsunami in Fukushima, Japan.

The EVs served as mobile electric generators for rescue teams and communities without power. The energy stored in the car batteries powered communications, lighting, community kitchens and charged power tools for rescue workers.

And in the UK, when power was cut off by Storm Eunice in 2022, EV drivers were able to use the Kia EV6 and the Hyundai Ioniq 5 to charge their laptops and power fridges.

In Australia, a woman powered her 11-year-old son’s dialysis machine during a power cut with her electric BYD. The technology to power a single appliance is called vehicle-to-load (V2L) charging and is also available on the Kia Niro, MG and VW ID cars.

The ability to send electricity from your car to the grid is the next step, called vehicle-to-grid (V2G) charging. The UK’s current fleet of electric cars have the potential to store 18GWh of electricity, double what can be held in the UK’s biggest storage facility, the Dinorwig pumped storage plant in Snowdonia. 

Alex Schoch of Octopus Energy explains: “We recently moved past a million EVs on UK roads – a major milestone – but their true power for storing energy remains untapped.”

V2G can help the grid to use more renewable energy because when demand is low, the grid is powered mostly by renewables, like wind turbines running overnight. An EV can charge with low-cost energy, store that energy and at peak times send the renewable energy back to the grid.

This works well with renewables like solar and wind, and nuclear energy which are not able to increase their output in response to high demand. National Grid is rapidly building grid-scale battery systems and other energy storage, but currently we are still using gas peaking plants to balance the grid.

These gas-powered stations only come on to generate electricity when demand exceeds the supply. The operators of these plants are paid very high prices for their electricity to compensate them for maintaining plant that will stand idle most of the time, pushing up electricity prices for consumers.