London South Bank University (LSBU) has secured a €7m EU research grant to examine whether cooling facilities in refrigeration warehouses and food processing plants could be used to store and supply electricity.

LSBU’s School of The Built Environment and Architecture, one of the leading urban engineering and sustainability research centres in the UK, is to investigate the potential of a promising new technology – cryogenic energy storage (CES) – to solve the problem of how to store excess renewable energy.

With more and more of our energy coming from renewable energy sources, such as wind, tidal or solar power, there is a heightened risk of fluctuations in our future electricity supply, due to the unpredictability of weather patterns. Technology to store excess energy from periods of high production, for release during periods of low production or high energy demand, is currently very limited, but would be of great significance to the energy industry.

The grant will enable LSBU to lead a pan-European consortium of researchers on a three and a half year CES project entitled CryoHub. LSBU’s share of the €7m grant is €2.2m. The grant bid was led by Professor Judith Evans, with significant input from Dr Alan Foster and Tim Brown. At the centre of CryoHub is the prospect of using CES to store and generate electricity on a mass-scale.

Professor Evans explained how the CES technology works in practice: “CES essentially uses cheap, off-peak electricity to convert air into a liquid, which can then be stored over a long period of time in a storage vessel. Turning the liquid back to gas, by removing it from the store and applying heat to it, will produce a huge increase in volume and pressure – enough to power a turbine to generate electricity which can then be supplied back to the grid.

“Because the liquid can be taken out of storage on demand, the technology can be used to restore electricity to the grid when energy demand is predicted to outstrip supply. It could also be used locally, also saving grid energy. CES is therefore a great complement to renewable energy sources, as it effectively safeguards against any periods of intermittent supply and helps to stabilise the energy grid.”

While at present a highly promising technology, CES is not yet efficient enough to be rolled out on a large scale, as the system currently has relatively low ‘round-trip’ efficiency when you compare the energy going in versus the energy coming out. CryoHub hopes to improve CES efficiency by aligning it with pre-existing powerful cooling and heating facilities found in industrial refrigeration warehouses and food processing plants. It is hoped that clever design and integration of existing equipment for cooling and heating processes will enable sufficient CES efficiency gains to be made to make the technology market-viable in the near future.

Professor Graeme Maidment, Director of LSBU’s Centre of Air Conditioning and Refrigeration Research, commented: 'This grant win is a fantastic success and builds on a portfolio of research funding totalling over £6 million in the last 10 years. It strengthens LSBU’s position as an internationally leading research team working in an important engineering discipline that contributes to many aspects of everyday life.'

The technology’s ability to generate energy at peak grid demand is just one potential benefit of LSBU’s research. The refrigeration and processing plants at the centre of the project are themselves high consumers of electricity. CryoHub will investigate the potential for CES to shift the energy that these units use from periods of highest demand on the grid to times when demand is much lower. The researchers estimate that if the technology were applied to just 10% of the refrigerated warehouses and food factories in Europe it could save nine million tonnes of carbon dioxide equivalent emissions per year.

Professor Evans continued: “With Europe committed to generating 20% of its required energy from renewable sources in 2020, it’s vital that renewable energy sources are fully and properly integrated with industry so that supply from the grid can continue to meet demand. Only through advances in technology will this be achievable, so CryoHub will be an important project in helping Europe to move towards a low-carbon economy.”