How it works
The LAES system consists of three main parts: The charging, the storage and the discharging part. The charging part runs when electricity needs to be stored. Electricity is used to compress and cool air to -190 °C and then liquefy it through expansion – just like in any cryogenic air separation plant that Linde builds. Then, the liquid air is stored in near ambient pressure conditions in an insulated tank at a density of more than 700 times of ambient air. When power is needed in the grid, liquid air is pressurized using a pump, heated up & evaporated and finally expanded in the discharging part in one or several turbines which generate power. The system performance can be improved by storing and recycling the cold of the air and the heat of compression; further, external heat or fuel can be tied into the power generation process to improve efficiency and power output.
Strengths and applications
The system consists of mature and proven technology only: turbomachinery, heat exchangers and tanks are all available, proven and provide significant economy of scale. We expect LAES to be a competitive storage alternative in applications above 50 MW and for storage durations from 2-20 hours. The system can be built either as a pure power-to-power storage or combined with usage of industrial waste heat or fuel; in the latter case it can also be run as a gas turbine peaker (even when the storage is empty).
The main advantage in comparison with classic large-scale alternatives (pumped hydro / compressed air energy storage) is that no geology is involved; therefore LAES can be built anywhere, erection time is short, and it is much less prone to public resistance and geological risks.
A 1600 m3 liquid air tank can store about 220 MWh of electricity.
Large-scale system ready for demonstration
With a technology partner, we have developed an 80 MW power output system based on available components that is ready to be demonstrated. Simultaneously we are developing the next generation of advanced systems with improved performance.