by Chad Redman
Asymmetrical energy production and consumption over the course of the day creates challenges all around the globe, which is why effective and efficient energy storage technologies are the subject of widespread research and development. Liquid Air Energy Storage (LAES) is one fascinating method for storing excess, cheap off-peak energy, and taking advantage of it when energy production falls and demand rises in the evening. The Energy Storage Association describes the systems behind LAES, including ways in which waste from unrelated processes can be turned into valuable energy.
LAES utilizes super-cooled air or nitrogen, transformed from a gas into a liquid, to store energy in insulated tanks. The first stage of the LAES system is dubbed the “charging” stage, and involves the intake of ambient air and the cooling of that air till it assumes a liquid form. The second LAES stage is energy storage, usually holding the liquid air in tanks similar to those used for liquid nitrogen, oxygen, and LNG. Finally, the third stage of LAES is the “power recover” stage, in which the liquid air is evaporated and heated to ambient temperature. This process raises the pressure of the air which can then be used to run a generator.
LAES has several characteristics that make it attractive in the long run as a money and energy saving device. First, the hardware components required to construct a functional LAES system are highly prolific, and boast reliably long lifespans. Furthermore, there are a few processes that can be used to boost the efficiency of LAES systems. First, very cold air produced from the third stage of LAES can be stored and reused to liquefy air on the next cycle. Cold air from other industrial processes can be utilized similarly. Similarly, this situation is true in reverse; hot air produced in the first stage of LAES can increase efficiency of the energy recovery stage. Waste heat from external industrial processes can be used in the same way.
“Liquid Air Energy Storage (LAES).” EnergyStorage.org. N.p., n.d. Web. 02 Feb. 2015.