Seed funding for medium-duration eTanker energy storage

A university spin-out that spotted a gap in the market for medium-duration energy storage has raised £1m in seed funding.

CEL team at Bilsthorpe (Image: CEL)

The funding has been awarded to Cheesecake Energy Ltd (CEL), which is developing eTanker, an advanced thermal and compressed air energy system that could cut the cost of storing energy by 30-40 per cent.

The Nottingham University spin-out believes eTanker could be used in sectors including electric vehicle (EV) charging, heavy industry and renewable energy generation.


The company will use the funding to develop its manufacturing capabilities and support product development of eTanker which can fulfil medium-duration energy storage requirements (4-200 hours) that alternative technologies cannot satisfy.

“We’re competing with longer-duration lithium-ion systems and flow batteries, but offer a lower cost and much more sustainable offering, with no rare or toxic materials and with a design that can be fully recycled at end-of-life,” said CEL CEO, Mike Simpson. “Our system stores much of the energy as heat in inert rock in a way that is passively safe, avoiding the fire risk faced by some battery technologies.”

The eTanker takes established compressed air energy storage concepts and transforms them by storing two-thirds of the electricity in the form of heat which can be stored at far lower cost.

To store the energy, electric motors drive compressors, which deliver high pressure air and heat into air tanks and thermal storage units respectively. When the electricity is required, the high-pressure air and heat is passed back through the same compressor which turns a generator to produce electricity.

ETanker uses an end-of-life diesel truck engine that is re-manufactured before being integrated into CEL’s system with an electric motor to drive the unit as a compressor and in reverse as an expander.

CEL will undergo an additional round later in 2021 to deploy pilot projects with fleet operators and industrial manufacturing businesses.