Liquid Air Energy Storage

The process is simple:


Liquid Air Energy Storage (LAES) uses electricity to cool air until it becomes a cryogenic liquid. The liquid air is stored in insulated tanks at low pressure. When electricity is needed, the liquid air is pumped, heated and expanded back into a gas, driving turbines to produce electricity. Its appeal for Europe is that it can be developed without the same geological constraints as cavern-based storage.

Heat integration with industrial processes or waste heat can further improve overall system efficiency.

Where is turbomachinery used?

  • Charging: Compressors increase air pressure before the liquefaction process, enabling efficient cryogenic cooling.
  • Discharging: Expansion turbines recover the stored energy by converting the expanding air into mechanical power that drives an electrical generator.

Main configurations:

Stand-alone LAES: In a stand-alone system, the charging, storage and discharge processes are integrated within one plant. Electricity drives compressors and refrigeration equipment to liquefy the air. The system stores the heat generated during compression and the cold recovered during discharge so that both can be reused in the next operating cycle. This configuration does not depend on an external industrial heat or cold source and can therefore be located according to electricity-system needs.

LAES integrated with industrial waste heat: LAES can be installed close to an industrial facility that produces heat which would otherwise be released into the environment. During discharge, this heat is used to warm the pressurised liquid air before it enters the expansion turbine. Increasing the temperature of the air before expansion increases the energy available to the turbine and can improve electricity output and overall system efficiency. Potential integration sites include energy-intensive industrial facilities and thermal power plants with suitable waste-heat streams.

LAES integrated with a gas turbine or another thermal power plant: LAES can be combined with a thermal power-generation system. Waste heat from the power plant can be used to heat the pressurised air before expansion, while LAES can provide stored electricity, peak-load capacity and additional flexibility. Integrating LAES with a gas turbine system could create a combined peak-load plant with greater discharge capacity than either system operating independently.

LAES integrated with waste cold: LAES can also use cold from nearby industrial processes, particularly facilities handling cryogenic products. The external cold can reduce the electricity required to cool and liquefy the air during charging. This configuration can be particularly relevant near liquefied natural gas terminals, industrial-gas facilities or other sites where low-temperature energy would otherwise remain unused.

LAES integrated with both heat and cold sources: Where suitable industrial infrastructure is available, LAES can recover external heat for the discharge process and external cold for the charging process. This reduces energy losses at both ends of the storage cycle. Such a configuration may be especially attractive in industrial clusters, ports and energy hubs where electricity infrastructure, heat sources and cryogenic processes are located close together.

Why is LAES important to support the Energy Transition?

LAES can store surplus electricity for several hours or longer and return it to the grid when renewable generation is lower or electricity demand is higher.

Unlike pumped storage hydropower and underground CAES, LAES does not require specific topographical or geological formations. It can therefore be considered for a wider range of locations, including sites close to renewable generation, industrial facilities, demand centres or congested parts of the electricity network. LAES can also be integrated with suitable industrial waste-heat or waste-cold streams to improve system performance.

LAES offers:

  • Storage durations ranging from several hours to multiple days.
  • Flexible siting without the need for underground caverns or reservoirs at different elevations.
  • Established component technologies from the turbomachinery, industrial-gas and cryogenic sectors.
  • Potential applications in energy shifting, renewable integration, balancing and congestion management.
  • Opportunities to improve system performance by integrating suitable industrial waste-heat or waste-cold streams.