EVs and PHEVs can only be as ‘green’ as the electricity used to charge their batteries. Recent results from EV trials show a typical carbon dioxide emissions rating to be around 100g/km, when the car is charged from a typical power supply in the UK. Given that a brand new Volkswagen Polo turbo diesel injection has an emissions rating of 91g/km, it is difficult to see how electric vehicles fed from today’s UK electricity generation supply are significantly better than petrol or diesel vehicles. To have a major effect, the introduction of electric vehicles must be accompanied by an almost total decarbonization of the electricity supply.

—“Electric Vehicles: charged with potential”

In preparing its report, the Academy identified four major technical issues:

• The availability of high energy-density batteries at a price and with a long enough cycle life for electric vehicles to be economically viable;

• The practicalities of charging vehicles, particularly for users without off-street parking;

• The electrical distribution infrastructure to provide power to millions of charging points; and

• The need for a national energy system and smart grid that can recharge millions of electric vehicles using low-carbon electricity without overwhelming local distribution circuits.

Swapping gas guzzlers for electric vehicles will not solve our carbon emissions problem on its own. When most electricity in Britain is still generated by burning gas and coal, the difference between an electric car and a small, low-emission petrol or diesel car is negligible. We welcome the fact that the motor manufacturers are so ready to take on the challenge of developing mass market electric vehicles. We also welcome the new Government’s commitment to mandating charging sockets for electric vehicles and plug-in hybrids, but establishing these as the technology of choice for personal transport is only one aspect of what is needed to reduce transport emissions.

—Professor Roger Kemp of Lancaster University, Chair of the Academy’s Electric Vehicles working group

The current contribution of renewable and low-carbon generation to the UK’s energy supply is one of the lowest in Europe, the report points out. If the UK is to meet its renewables targets and ensure a greener power supply to electric cars, a range of new low-carbon energy sources will be needed, including new nuclear power stations, wind farms and tidal barrages.

As the Academy recognized in its recent report Generating the future: UK energy systems fit for 2050, creating this new energy system will require a massive change program and robust leadership by Government.

Delivering all four programs will be more challenging than any other engineering project of the last century. We have a unique opportunity just now to ensure that all the policies work together and to recognize the critical links between them. For example, recent discussions on introducing smart meters to every household did not include the functionality required to manage electric vehicle charging, which could render the first generation of smart meters obsolete as the electric vehicle market grows.

—Professor Kemp

There are ways to allow electric vehicles and plug-in hybrids to take over most of the present uses of gasoline and diesel vehicles but these are unlikely to develop without financial incentives for early adopters, the report finds. In the medium term, the new Government will need to indicate how it intends to replace road fuel taxation as electric vehicles gain market share, to allow manufacturers and potential users to make informed decisions.

Electric vehicles could provide a major contribution to meeting the target of an 80 per cent reduction in greenhouse gas emissions by 2050. However, they will only be built in mass production numbers when there is a compelling sustainable social and business model for their use to allow manufacturers to plan for a long-term market and when the new vehicles have a real carbon efficiency benefit over the latest internal combustion engines.

—Richard Parry-Jones, a member of the working group and former Group Vice President of the Ford Motor Company

A more likely alternative to widespread adoption of pure electric vehicles with their infrastructure requirement would be the plug-in hybrid. While hybrids have most of the environmental benefits of electric vehicles, they do not rely on such a comprehensive network of recharging points at multiple destinations. Plug-in hybrids could be adopted quickly as family cars or executive cars, leaving pure electric cars to achieve initial market penetration as second cars, doing low mileage and thus having little impact on carbon emissions.

The report makes five specific recommendations to advanced electric mobility:

• The UK Government needs to outline its long-term policy direction for EVs in order to provide the right incentives for early adopters as well as providing a stable policy environment for the EV market to develop over time. This policy needs to extend into strategies for the timely investment in the required infrastructure, the ownership of that infrastructure and the timescales over which it must be implemented so as not to delay the development of EVs and PHEVs as mass market solutions. Government also needs to map out intentions for the funding of road networks in the medium term as tax revenues from conventional road fuels reduces.

• The integration of low-carbon energy, universal broadband provision and smart grid policy areas to adopt a fully systems-based approach to ensure that all work together and the critical links between them are explicitly recognized.

• The automotive industry, with the support of other interested parties, including UK and European governments, must proactively develop international standards for charging EVs and billing protocols.

• The Government, Ofgem and the UK electricity industry must develop protocols to integrate the long term needs of EV charging into current plans to roll out smart meters and smart grid technologies country wide. Not doing so will risk either stifling growth in the EV market or being faced with early obsolescence of the first generation of domestic smart meters.

• Further research and development of EV batteries, energy management systems and fast charging is needed to maintain and increase the carbon advantage that EVs currently enjoy and to reduce costs of the battery and EV drive train relative to internal combustion engine vehicles. This needs to be achieved in parallel with continued decarbonization of the UK electricity system.

Electric Vehicles: charged with potential was prepared by a working group consisting of the following group of Academy Fellows, commenting in a personal capacity and not necessarily as representatives of their respective organizations:

• Professor Roger Kemp FREng, Lancaster University (Chair)
• Professor Phil Blythe, Newcastle University
• Dr Chris Brace, Bath University
• Pete James, Prodrive
• Richard Parry-Jones FREng, RPJ Consulting
• Davy Thielena, KEMA Consulting
• Dr Martyn Thomas CBE FREng, Martyn Thomas Associates
• Professor John Urry, Lancaster University
• Richard Wenham, Ricardo plc

The Academy is sponsoring a debate at Cheltenham Science Festival on 13 June entitled Electric dreams: the future of cars. Professor Roger Kemp will join psychologist Harry Witchel and electric car enthusiast Robert Llewellyn to explore the future of battery powered vehicles.

Resources

• Electric Vehicles: charged with potential