The joint research, carried out by Ricardo and the National Grid, found that by ‘reverse-charging’ vehicles during peak times the stored energy in EV batteries could balance spikes in electricity usage and reduce the Grid’s reliance on fossil fuels.

It claims the projected fleet of plug-in EVs needed to meet 2020 emissions targets could provide enough electricity to account for 6 per cent of grid balancing requirements during the day, or 10 per cent at night.

Vehicle-to-Grid systems also offer returns of up to £8,000 for a three-phase installation. While the cost is high for a country-wide roll-out, it makes them ideal for captive vehicle fleets, battery exchange depots and batches of expired batteries where the cost can be offset across several different vehicles or battery packs.

Ricardo chief technology and innovation officer Prof. Neville Jackson said: ‘The energy storage capacity of a future electric vehicle fleet needs to be viewed as an integral part of the power system.

‘If operational synergies at both a grid and distribution network scale are exploited, some of the obstacles to the mass roll-out of electric vehicles will be tackled and the associated costs of necessary power system reinforcements and upgrades will be minimized.

‘The battery will represent a substantial part of the capital cost of an Electric Vehicle for the foreseeable future and working this asset to realise further value could be important in providing a competitive product to consumers.’