The Carbon Dioxide Removal Potential of Liquid Air Energy Storage: A High-Level Technical and Economic Appraisal

Liquid Air Energy Storage (LAES ) is an energy-storage technology, currently operating at pilot plant scale. It relies on the compression, cooling and subsequent liquefaction of ambient air, as a means of storing energy. Subsequent reheating of the air (using ambient, stored, or waste heat ) allows re-vapourisation of the air at significant pressure – to power a gas turbine or reciprocating engine , effecting energy recovery. Inherent in the liquefaction process is a need to remove water and CO2 , which would otherwise pose materials handling issues at cryogenic temperatures. This CO2 can potentially be recovered and stored (e.g. geologically), thus preventing it acting as a greenhouse gas. This Carbon Capture and Storage (CCS ) add-on renders LAES a form of Carbon Dioxide Removal (CDR) , albeit as a by-product. Compressed Air Energy Storage (CAES), with additional cooling offers potentially-comparable CDR potential. Our crude numerical analysis finds that neither LAES or CAES has the capacity to conduct full planetary-scale CDR on centurial timescales. However, CDR by-products from the industry are capable of providing a trillion-dollar scale (USD) revenue stream this century to the LAES industry – and a large (but less certain) revenue stream to the CAES industry. This could potentially be instrumental in effecting a switch to LAES on costs grounds, as well as substantially modifying the scaling and placement of LAES or CAES plants.