Large-scale, cost-effective energy storage is generally considered to be one of the key missing pieces of the puzzle for a sustainable energy future. Compressed Air Energy Storage (CAES) is a form of energy storage with signifcant potential for global expansion which is entirely composed of mechanical and thermal components. There are two commercial grid-scale CAES plants currently in existence; Huntorf, Germany (commissioned in 1978 -- see Figure 1) and McIntosh, Alabama (commissioned in 1991) which represent about 440 MW of power and in excess of 3 GWh of energy storage. These two plants, however, are not purely electricity storage, as they also use natural gas, running a process very similar to an open cycle gas turbine except that the air is pre-compressed, rather than operating the compressor and the turbine simultaneously.

To overcome the need for fossil fuel, variations of the CAES concept which do not use natural gas have been proposed. In Adiabatic CAES (ACAES), heat generated during the compression is stored and then returned to the air prior to expansion, replacing the use of fossil fuel. An illustration of ACAES operation is shown in the Figure 2 below. However so far - despite much promising research - a successful prototype ACAES plant has yet to be demonstrated. Our research in the ESES lab aims to bring ACAES from concept to reality. We perform thermodynamic analysis, simulation, modelling and conduct experiments designed to improve the performance of these systems. Our work spans from designing individual system components (for example, heat exchangers in ACAES systems) to whole system design, optimisation and integration of ACAES into wider energy systems.

Recently, we have published several influential papers on ACAES. These can be found on my google scholar profile. If you are interested in why ACAES is yet to achieve widespread viability then please check out this article in iScience exploring the issue.