EV charging point on street

Analysis: Electric-car developments raise grid questions

Electric vehicles need a charging infrastructure. E&T invites IET members to get involved in developing the standards.

In 2006 the Stern review suggested that countries needed to spend 1 per cent of their GDP to stop greenhouse gases rising to dangerous levels. Failure to do so would lead to damage resulting from climate change that could cost 5 per cent of global GDP. While the emissions from most sectors are falling, transport emissions have continuously risen over the past decade and road transport accounts for roughly 22 per cent of UK CO2 emissions. We need to move much faster towards sustainable transport.

The change to alternative fuels such as hydrogen, biofuels and electricity has been slow. Yet, the King Review of Low-Carbon Cars suggested that if substantial progress is made in solving electric vehicle technology, an almost complete decarbonisation of road transport is possible by 2050. And progress is being made. Hardly a week goes by without further announcements from major car companies on new trials for electric vehicles. UK government has created a number of demonstrator schemes to further accelerate growth.

However, the UK's infrastructure has been optimised for petrol and diesel. Both fuels have unique properties which are ideal for transport: they are energy-dense, relatively cheap to produce and vehicles can be refuelled quickly.

Range anxiety (the fear of being stranded for hours while a flat battery recharges), together with the price premium of electric cars, still constitutes a major barrier to the introduction of electric vehicles. Yet, according to Department for Transport statistics, 94 per cent of all road journeys are less than 25 miles (40km) long. This means that most journeys can be made even with current battery technology (varying from 50-200 miles with an average performance around 80-100 miles).

To reduce range anxiety, car manufacturers are introducing 'fast' and 'rapid' charging regimes using DC power sources or three-phase AC, reducing charging times to 30 minutes. This development, however, has three major implications: charging has to be done safely, sufficient low-carbon electricity needs to be available and, as the number of electric vehicles increases, the impact on the electricity network will need to be managed by introduction of smart grid technology.

Phil Blythe, chair of the IET's Transport Policy Panel, says: 'Strategically, the understanding of how electric vehicles perform under different conditions and how this may affect the overall range of the vehicle is critical to identifying and solving the barriers that may exist to making the general public and businesses consider electric vehicles as being a suitable and safe 'mass-market' vehicle technology. Trials are under way to explore how these vehicles perform under different weather and temperature conditions, the effect of an individual's driving style and the effect of different levels of congestion and the road topology.'

In the North East of England, Newcastle University, as part of the electric vehicle demonstrator funded by the Technology Strategy Board and One North East, is equipping electric vehicles with data-logging equipment to examine such questions and fill in the knowledge gap. This will define the density of public and workplace charging points and also the peak demand on energy networks at these locations and more critically at home, where many users will choose to charge their vehicles overnight (which may put significant strain on local supply networks).

If users trust the technology, find it reliable and believe what is said on the State of Charge display, they may recharge their vehicles in a more rational way than people do with mobile phones, where we tend to plug them in at night even though they may have three or four days' worth of battery life left.

The ample introduction of charging points leads on to the discussions of interoperability and safety. Ian McDonald, technical chair of the IET Electric Vehicle Infrastructure Steering Group, points out that legislation and regulations have to keep pace with new and emerging technology. A systematic review of the implications of new technologies has to be performed in order to maximise the benefits and minimise financial and safety risks.

Regarding electrical safety, there are already standards that the industry has to adhere to, including BS EN 61851 and the IEE Wiring Regulations (BS 7671:2008). However, a number of issues still need to be addressed when providing charging infrastructure. Car owner, car manufacturer, battery manufacturer, battery leasing company, charger owner and charger manufacturer all play a part in the safe roll-out of electric vehicles and infrastructure.

The IET has established a working group on electric vehicle charging infrastructure to bring a large group of stakeholders around one table and to help provide guidance. If you too would like to get involved, contact Yvonne Hübner on policy@theiet.org.

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