Liquid air energy-storage set for the big time after German deal

UK technology developer Highview Power Storage (HPS) expects to see the first multi-megawatt plant using its liquid air energy-storage (LAES) concept built next year, after signing a commercialisation deal with German industrial gases group Messer.

The HPS system – which recently completed year-long trials of a 300kW pilot-facility at an 80MW biomass plant in the UK – will initially be developed for use at gas-production plants, with a view to storing surplus power from future large-scale renewables deployments.

The agreement gives Messer exclusive rights to HPS’ LAES technology in return for annual licensing fees and access to its engineering expertise in gas liquefaction technology – a core part of the cryogenic energy-storage process.

LAES cryogenically cools air to minus 196ºC – a concept already applied in liquid natural gas (LNG) transport – and stores it as a liquid in an insulated tank at atmospheric pressure.

When released and pumped-up to high pressure, then vapourised and heated to ambient temperature, the air expands to 700 times its liquid volume to drive a turbine.

This powers a generator to feed electricity to the grid. The cryogen is then evaporated and recycled to give the system a round-trip efficiency of about 50%.

The UK LAES pilot system, which was part-funded by a £1.1m government grant, has a 2.5MWh storage capacity. HPS believes the technology can be scaled up to a 50MW-plus system with more than four hours of storage capability.

HPS has also formed a partnership with African conglomerate Basil Read Energy (BRE) to roll out the LAES technology in southern Africa.

BRE is targeting installations of the LAES system for large-scale energy storage at “intensive users” including mines, refineries and steel mills.

HPS and BRE have launched a feasibility study for a specific first site, expected to be a 10MW plant with more than 50MWh of stored capacity.