They claim 60% in the basic configuration, or 70% if coupled with a low grade heat source: https://www.highviewpower.com/benefits/ https://www.highviewpower.co

They claim 60% in the basic configuration, or 70% if coupled with a low grade heat source: https://www.highviewpower.com/benefits/ https://www.highviewpower.com/benefits/ When I searched Google Scholar, I found this 2016 report from their first 350 kilowatt pilot plant at the University of Birmingham: https://www.researchgate.net/profile/Adriano_Sciacovelli/publication/303814262_Liquid_air_energy_storage_-_Operation_and_performance_of_the_first_pilot_plant_in_the_world/links/5757c6aa08aef6cbe35f5ad9.pdf https://www.researchgate.net/profile/Adriano_Sciacovelli/pub... That pilot project claimed less than 25% efficiency, but the authors seemed confident efficiency could be raised. A 5 megawatt demonstration plant has been running in the UK since 2018: https://www.greentechmedia.com/articles/read/highview-power-completes-uk-liquid-air-storage-plant https://www.greentechmedia.com/articles/read/highview-power-... I presume that the 0.35 MW and 5 MW projects worked reasonably well if they are now trying to develop a 50 MW project.