Using electric vehicles to store energy and feed back into the grid could soon save the UK’s consumer hundreds of pounds a year, a new T&E study finds. EVs equipped with bidirectional charging can act as ‘batteries on wheels’ that draw down electricity at times of oversupply and give back when demand is higher. But their potential is unlikely to be realised without common standards to ensure interoperability between all EVs and chargers.
By allowing EVs to draw down excess electricity when it’s cheap, bidirectional charging could save UK EV drivers 11% on annual electricity bills according to the study, or £190 per year by 2040. If bidirectional charging was combined with home solar panels, this could reduce bills by up to 43%, equating to reductions of up to £380, depending on factors such as location and the vehicle’s battery size. Bidirectional homechargers are expected to only be around £80 more expensive than conventional wallboxes in the future.
Bidirectional charging can also extend the life of EV batteries – contrary to commonly held concerns about cell degradation due to regular charging and deloading. Battery lifetimes could be extended by up to 9% compared to standard EV charging practices, the report finds, as the car is maintained in an optimal state of charge.
Overall, vehicle-to-grid (V2G) technology could help the UK energy system save £2.25 billion a year by 2040, according to the report by research institutes Fraunhofer ISI and ISE for Transport & Environment (T&E). This could result in a saving of more than £15 billion between 2030 and 2040, T&E finds.
By storing excess renewable energy that would otherwise be lost, the UK’s EV fleet could contribute up to 3% of the UK's annual power requirements. This would make EVs the sixth largest power ‘supplier’ in the UK.
Transport & Environment is calling on the UK Government to change UK vehicle approval rules to make sure that the onboard charger of every new EV is capable of bidirectionality and to adopt new measures to ensure all private and slow public chargers are capable of charging both ways. Vitally, the UK government must get to grips with ensuring that the grid is prepared and smart so V2G benefits can be maximised.
Ralph Palmer, UK Electric Vehicles Lead at T&E, said:
“While electric vehicles already offer huge running cost savings to drivers, maximising the potential of bidirectional charging will unleash a new wave of benefits to households by bringing down energy bills, and ensuring our energy system is cheaper to run, more stable and more secure from price shocks. For a Government with a 100% clean power mission by 2030, it’s a no-brainer to not only accelerate the transition to electric vehicles but also develop a clear regulatory framework to ensure all new EVs and slow public and private chargers are capable of bidirectionality to support this crucial mission.”
ENDS
Notes to editors:
If you would like to speak to a spokesperson or have any questions, please contact Alexander Killeen via alexander.killeen@transportenvironment.org or 07086431577.
Transport & Environment UK is the UK national office of clean transport NGO, Transport & Environment, whose aim is to achieve a zero-emission mobility system that is affordable and has minimal impacts on our health, climate and environment and is accessible to all.
