Japanese car maker Nissan, E.On Drive and Imperial College London have published a white paper highlighting the carbon saving and economic benefits of vehicle-to-grid (V2G) technology.

The paper explores how the bi-directional charging capability of electric vehicles (EVs) could contribute to lower emissions and help achieve long-term goals in climate change. It offers supporting recommendations and calls for the introduction of incentives to accelerate widespread adoption of V2G charging systems, enabling potential benefits to be unlocked.

It also addresses some of the challenges that will be faced in the early days of V2G, particularly around creating a reliable business case for evolving energy markets and regulation.

Nissan, E.On Drive and Imperial College are partners in a commercial fleet V2G project – known as e4Future – which aims to demonstrate how electric vans and cars can support the UK grid and provide a profitable and sustainable option for business fleets.

The e4Future project is part of the V2G competition, funded by the UK government’s Department for Business, Energy & Industrial Strategy (BEIS) and the Office for Zero Emission Vehicles (OZEV), in partnership with Innovate UK, part of UK Research & Innovation.

Andrew Humberstone, managing director of Nissan Motor in the UK, said: “There is enormous potential in vehicle-to-grid to deliver huge savings, both in financial terms for electricity system operators and vehicle fleets, and in environmental terms, by significantly cutting CO₂ emissions across the UK power system. Nissan is at the forefront of efforts to realise this potential.”

The white paper indicates that V2G has the potential for reducing carbon emissions from the power system to as low as -243gCO₂/km. Electricity system operation cost savings in the UK could be up to £12,000 per annum per EV and CO₂ reduction of approximately 60 tonnes a year per EV. Annual fleet V2G charging benefits could range between £700 and £1250 per vehicle.

“Our research has demonstrated that V2G can provide very substantial economic benefits to the power system as well as reduce carbon emissions,” said Goran Strbac, chair in electrical energy systems at Imperial College London. “This revealed that the additional flexibility provided by V2G fleets can considerably improve system efficiency and reduce investment in new low-carbon generation, while meeting national decarbonisation targets.”

In January 2018, BEIS and OZEV announced that 21 projects – eight feasibility studies, five collaborative research and development projects, and eight real-world V2G trial projects – were to receive funding of £30m to develop the business proposition and core technology to support V2G deployment in the UK, including its demonstration with large-scale trials.

The projects involve more than 50 industrial partners and research organisations from the energy and automotive sectors, marking one of the largest and most diverse activities on V2G in the world, and trialling more than 1000 vehicles and V2G charger units across UK.

The projects represent a step towards the transition to low-carbon transportation and a smart energy system. Allowing EVs to return energy to the power grid when parked and plugged in for charging will increase grid resilience, allow for better exploitation of renewable sources and lower the cost of EV ownership, leading to business opportunities and advantages for EV users and energy consumers.

V2G technology allows electricity to flow in both directions to and from electric vehicle batteries, allowing energy stored in the battery to be sold back to the grid when demand for power is high. Vehicles can then charge when demand is lower or renewable generation is high, reducing reliance on fossil-fuelled generation and giving V2G a role in carbon reduction efforts. It can also release capacity on the electricity networks that distribute power around the country.

Fleet vehicles are often uniquely suited to V2G applications, due largely to regular and predictable usage patterns, and the fact they often return to base at the end of the working day, where they sit idle overnight. This provides perfect conditions for V2G to use the energy stored in their batteries, before ensuring the vehicles are fully charged and ready for use again the next morning.