Liquid Air Energy Storage
Liquid Air Energy Storage (LAES)
One of the most efficient methods for storing excess electricity is the Liquid Air Energy Storage (LAES) technology. In so doing, the air is compressed and then cooled to the extent that the initially gaseous air changes into the liquid aggregate state. The liquefied air is then stored. If the electricity demand rises in the power grid, a pump brings the liquid air to a higher pressure followed by its evaporation. The pressurized gaseous air is heated and drives highly efficient turbomachinery to generate electricity. LAES can be used as a storage technology up to a gigawatt hour.
A real advantage as against other processes is that no particular geological requirements for the site come from LAES - so ruling out lengthy, complex approval procedures. Moreover, the expectation is for relatively short construction and lead times and this opens the prospect of rapid implementation.
In addition, the required components represent well-developed uniform processes which for many years now have been deployed in the process/power plant industries. Only minor modifications are needed to adapt them to the LAES system. In addition, its integration into an existing power plant or industrial site would mean availability of the required grid and gas infrastructure. The system can also be run as a non-energy storage backup gas power station with a 40%+ efficiency.
Dependent on a number of process parameters, the calculated storage efficiency is over 70% and thus comparable with those of pumped hydro energy storage plants. In addition, process storage efficiency can be raised further given the availability of industrial waste heat (from surrounding power plants) and/or waste cold (LNG terminal).