The proliferation of electric vehicles is not sustainable, argue critics, because electricity networks will not be able to cope when everybody and their dog plug in EVs en masse. However, the opposite might be the case: battery-powered vehicles could pump electrons into the power grid. When the EVs are not being used, that is, which, like for the majority of motor vehicles, is most of the time.
Electric vehicles could therefore soon provide a widely-distributed hive-style bidirectional battery resource that would store green energy when it might otherwise go to waste and feed it back into the electricity grid at times of peak demand.
The $27,400 Nissan Leaf is one of the few widely-available electric cars which is already bidirectional: it can suck in power and pump it out again. The $47,000 Ariya, the Japanese company’s new crossover all-electric SUV recently crowned as “Car of the Year” by Auto Express, is also so equipped. Theoretically, ten million Nissan EVs using the company’s Energy Share mode could meet peak electricity demand for the whole of the U.K.
There are 32 million motor vehicles registered in the U.K. Currently, only 500,000 of them are all-electric models, but as the U.K. will ban sales of new petrol and diesel cars by 2030, the uptake of EVs will accelerate. Pre-pandemic, roughly two million new cars were registered each year. According to figures from automotive analyst Jato, almost 4.2 million electric cars were sold worldwide in 2021, up 108% on 2020 and 198% on 2019.
Optimistically, almost half of the U.K.’s motor vehicles could be electric or hybrid electric by 2030.
The Leaf was a global electric car pioneer when it was introduced in 2010. Nissan introduced a second-generation iteration in 2019. 500,000 Leafs have been sold globally since the launch in 2010, Nissan said in 2020. The company’s factory in Sunderland, northeast England, can make 100,000 EVs a year.
Nissan’s electric vehicles can store and pump out electricity as well as suck it in for propulsion because they are equipped with CHAdeMO charging ports in addition to the more standard CCS ports. CHAdeMO is a standard charging mode in Japan, but automakers—except for Nissan—have not included the charging technology on cars available outside of the country.
In Japan, Nissan Leaf cars have powered disaster relief efforts—after earthquakes, especially—for more than ten years.
While fracking continues to generate headlines in the U.K.—key supporters of those MPs still in the Tory leadership race want their favored candidates to restart fracking and ditch net-zero commitments— since 2019, more electricity is generated on the British Isles by clean sources than fossil fuels. With the growth in onshore and offshore wind farms and the closure of coal plants, transport is currently the largest source of greenhouse gas emissions in the U.K., making it a no-brainer for politicians to push the uptake of electric vehicles.
The National Grid, which operates the U.K.’s electricity network, is optimistic that energy demand will not outstrip supply, predicting a 10% increase in electricity use even if “we all switched to EVs overnight.”
And if electric cars were recharged with domestic solar power or were hooked up at off-peak times and this electricity was sold to the grid at peak times, this would be a win for EV owners, earning them money, and a win for the grid, smoothing out the peaks and troughs in energy supply.
Household energy bills in the U.K. grew by 54% in April 2022, a record increase, and are set to rise again in October.
Hooking up an electric car so it can supply to the grid is a process known as vehicle-to-grid, or V2G. Hooking up an EV to power a house is known as vehicle-to-building, or V2B, and the generic capability for EVs to feed into the grid or buildings or to replenish power packs is known as VGI, or vehicle-grid integration.
The Nissan Leaf and Nissan’s electric van and the new Ariya are the most widely available EVs with vehicle-grid integration as standard.
The CCS charging system is expected to be VGI-compatible by 2025.
The U.K. government has grant aided the VGI sector. Several projects—generally using the Sunderland-built Nissan Leaf—have been backed by the Department for Business, Energy and Industrial Strategy and the Office for Zero Emission Vehicles. These projects include trials run by OVO Energy and Octopus Electric Vehicles which are due to report their findings soon.
VGI projects already up and running elsewhere in Europe include one in Denmark, which has been operating commercially since 2016. This was a collaboration between Nissan, multinational energy company Enel, and California-based Nuvve, a VGI specialist founded in 2010. (Earlier this year Nuvve signed a memorandum of understanding with the U.S. Department of Energy to commercialize VGI technologies in the U.S.)
Four years ago, Nissan supplied retired EV batteries to provide backup power and VGI capability to the Johan Cruijff Arena in Amsterdam, home to Ajax Football Club. The arena’s roof sports 4,200 solar panels, with the resulting electricity stored in the equivalent of 148 Nissan Leaf batteries; surplus electricity is sold to the Dutch national grid.
Even with the availability of millions of compatible electric cars it’s unlikely that vehicle-to-grid technology would ever be a leading source of power but, one day, it could be an integral part of an everyday energy mix.