Cheesecake Energy Ltd (CEL) is developing an energy storage technology that has a particular relevance to the electric vehicle charging market. Storing electricity in the form of heat and compressed air, the system aims to deliver storage capabilities at half the cost of battery equivalents, while lasting much longer and having a much lower environmental footprint. With support to date from both Shell GameChanger and Highways England, the team is moving quickly to deliver a full prototype that will demonstrate both the low cost and high efficiency of the technical solution. The system is particularly well-suited to charging fleets of electric vehicles where the grid connection is limited or constrained and where upgrades are costly, slow, or both. For sites with onsite renewable generation, the CEL technology allows maximum self-consumption, even where the vehicle fleet is away from base during the day. Compared to alternative energy storage technologies, CEL is able to achieve drastically lower technology costs, most notably, by: (1) repurposing ex-service truck diesel engines into electrically driven air compressors/expanders, and (2) using cheap, environmentally-safe materials and containers: gravel for storing heat and steel containers for air. The CEL system stores two-thirds of the electricity as heat, exploiting the extremely low cost of its thermal stores, and achieves a very competitive roundtrip efficiency of 70%. The system makes use of proven hardware to the fullest possible extent, cutting costs and development time, while also delivering circular economy benefits.