Liquid air storage: Science and technology
How refrigeration tricks store electricity without any chemistry
What this tab covers The physics and chemistry: how the energy is stored, which materials it needs (scarcity, toxicity, recyclability) and what makes it age.Liquid air storage uses spare electricity to cool air until it liquefies at about minus 196 C, keeps it in insulated low-pressure tanks, and later warms it so it expands through a turbine. It uses only common industrial-gas equipment, but loses roughly half the input energy.
Mechanism
FavourableCharging uses the Claude refrigeration cycle familiar from industrial gas plants: air is cleaned, dried, compressed and expanded until it condenses, shrinking about 700-fold. Discharge pumps the liquid to high pressure, reheats it with stored or waste heat and runs it through an expansion turbine. A cold store recovers the cold released on discharge for the next charge, and a heat store keeps compression heat; these two stores largely set efficiency. No fuel is burned in standalone plants. The generator is synchronous, so it also supplies inertia to the grid.1246
Liquefaction temperature about -196 C6 Volume reduction about 700 litres of air to 1 litre of liquid6 Electricity to make liquid air about 0.6-0.75 kWh per kg4Material scarcity and toxicity
FavourableThe plant uses steel tanks, compressors, turbines, heat exchangers and gravel or similar thermal stores. The working fluid is air. There are no critical minerals and no toxic or flammable stored medium.13
Degradation and ageing
FavourableCapacity does not fade with cycling because nothing is consumed chemically. Ageing is that of rotating machinery and cryogenic equipment, maintained on industrial schedules. Highview quotes an operating life of 40 to 50 years (developer claim). Boil-off from the tanks limits how long liquid can be held, though Highview claims retention over several weeks.1610
Claimed plant life 40-50 years (developer claim)10 Holding time multi-week retention claimed (developer claim)6Variants and projects compared1478
| Configuration or project | Size | Round-trip efficiency | Status |
|---|---|---|---|
| Standalone LAES with cold and heat recovery | n/a | about 50-60% | Commercial designs |
| Hybrid LAES using external waste heat or LNG cold | n/a | about 50-90% | Pilot and design studies |
| Pilsworth, UK (Highview) | 5 MW / 15 MWh | not published | Operating since 2018 |
| Carrington, UK (Highview) | 50 MW / 300 MWh, 6 h | not published | Under construction; Highview (Nov 2025) gave 2027 for liquid air storage, after early 2026 in 2024 reports; no commissioning announcement found by Nov 2026 |
| Golmud, Qinghai, China (CGDI with CAS) | 60 MW / 600 MWh, 10 h | not published | Commissioning, Dec 2025 |
Sources
- Energy stored as liquefied air: GBP 300m investment triggers construction of UK's first commercial-scale plant The Chemical Engineer (IChemE), 2024
- Energy storage innovation powers Highview scale-up UK Research and Innovation, 2024
- Explainer: does liquid air energy storage hold promise? Power Technology (Future Power Technology, issue 166), 2025
- Liquid air energy storage: a critical review (She et al., Renewable and Sustainable Energy Reviews 208, 114986); abstract checked via University of Birmingham repository Elsevier (Renewable and Sustainable Energy Reviews), 2025
- Highview Power's two UK LAES projects advance in Ofgem's cap-and-floor scheme POWER Magazine, 2025
- Highview surpasses half a billion pounds of funding with latest GBP 130M capital raise for phase one at Hunterston Highview Power via Business Wire, 2025
- China powers up world's largest liquid air storage project ESS News, 2025
- FAQs Highview Power (company website), 2026