The automotive and energy sectors will have to move closer together to make best use of electric vehicles in the energy grid
Electricity is at the focus of several of the most pressing debates facing the engineering sector at the moment: the technologies used to generate it and how best to deploy those to reduce carbon emissions and conserve reserves of fossil fuels as they begin to dwindle and the costs of extracting them rise ever higher; distribution, and how to direct its flow in the best way to reduce waste and ensure that supplies always meet demand; and its increasing use in transport.
EV battery technology is still developing, with further generations of technology expected; the Energy Futures Lab has research projects on new battery chemistry, including one where it is working with Williams Advanced Engineering (see Interview, p32), which designed the battery for the Formula E racing cars’ opening season. ‘It’s a problem that could be addressed with the right battery management systems and power electronics,’ Green said. ‘While you might imagine a full car park acting as a battery during the day, it might be better to imagine a different scenario. There is a possibility of operating battery swaps rather than recharging; in which case swapping-stations would have racks of batteries on charge and fully charged, waiting to be swapped into waiting vehicles.’ Such a system is very similar to grid-scale batteries such as those used by companies such as Alsthom in its smart-grid systems, which we featured in The Engineer earlier this year; these consist of arrays of individual battery units tacked together in a container equipped with inverters to convert AC to DC and back again — they are sometimes referred to as gridbanks — so the correct software and hardware to protect the batteries in an energy-storage configuration could be built into them more easily than into cars, Green said.
“We might see the emergence of a new player, which would buy electricity from the grid and supply it to chargers. That’s who car owners would pay when they charge their cars
Another question is how the commercial model might work. If vehicles are an integral part of an energy system, then who is responsible for the infrastructure? Who gets paid, and by whom? Hake and Linssen think it likely that a new economic sector might emerge. ‘It’s unlikely to be automotive companies, and it isn’t a clear part of the job that distributors currently do,’ Hake said. ‘So we might see the emergence of a new player, which would buy electricity from the grid and supply it to chargers. That’s who car owners would pay when they charge their cars and it would also sell electricity back to the grid when the car batteries are in discharge mode. Of course you also need to manage when cars are charged to take advantage of prices and capacity, which we know is a matter for smart grid operators; this new actor in the sector would be a part of that.