Electrification of transport is the single greatest opportunity to cause dramatic reductions in carbon emissions and air quality concerns from road usage. Achieving these high-priority aims calls for rapid and widespread adoption of electric vehicles (EVs) across the UK. As more people switch to EVs, cities will need to think how to provide charge to all those new vehicles. Retrofitting petrol stations and parking spaces with EV charging points is only part of the solution. Many of the existing petrol stations or new sites looking to install EV chargers will discover that the grid connection available cannot handle those levels of power. In many cases, upgrading the connection is infeasible as it is a very expensive and lengthy job.

Energy storage can help solve this issue. Charging stations can charge their energy store when there are no EVs around at a rate that is manageable for their grid connection. When called upon, the energy store can provide charge at a much faster rate than the grid connection alone would be able to. This approach allows installing EV chargers without upgrading the grid connection and it also allows the stations to reduce their electricity costs by charging the store at off-peak times.

Lithium-ion batteries from EVs could be used for this; however, they are expensive and they entail the mining of materials that are difficult to recycle, causing negative environmental impacts.

CEL is developing a new, green, and cost-effective energy storage system for EV charging stations called EVTanker. The system takes electricity from the grid and stores a part of it as heat and another part as pressurised air. The system uses electrically driven ex-service truck engines as the power-conversion machines for putting electricity into storage and withdrawing it when needed. Some key features of EVTanker are that: its elements are highly sustainable, it's safe and straightforward to operate, its main components will last for decades and it costs less than the cheapest lithium-ion batteries.

CEL has developed a prototype system to demonstrate the technology. The objective of this project is to take the technology from a full-scale laboratory prototype to a deployed pilot system. We will install and commission the pilot system at a local county council's vehicle depot, where it will be tested under real-life conditions.

CEL will partner with Open Energi to develop a robust control unit, which is one of the main prerequisites for transforming the laboratory prototype into an operational pilot plant. The control system will allow operating the system remotely and monitor the 'health' of different components. It will also be capable of scheduling charge/ discharge cycles to meet specific objectives, such as minimising electricity costs or ensuring that the energy store is charged using the greenest electricity possible.

At the end of this project, CEL will have installed, commissioned and tested the first energy store of this kind with a customer in the UK. The project will help boost the country's uptake of EVs and propel us towards a net-zero future.