A research undertaken by a team at College of Engineering, Oregon State University has disclosed a way to improve the efficiency of a type of storage of grid scale. The development is significant for a global shift toward renewable energy.
The move toward net-zero carbon emission means facing the unpredictable, intermittent nature of green power sources such as solar and wind and also defeat supply and demand gaps.
Such challenges necessitate energy storage via means beyond pumped hydro units. The energy storage facility comprises a turbine interlocked between two water reservoirs of different height, and huge lithium-ion batteries, stated one of the research associates.
The study revealed that one of those additional methodologies of energy storage, viz. compressed air could be improved via chemical reactions.
The findings published in Energy Conversion and Management are also relevant to a related technology.
As suggested by the name, the liquid and compressed air techniques collect energy that can be accessed when required by allowing stored air to expand and pass through electricity generating turbines.
However, compressed air energy storage (CAES) and liquid air energy storage (LAES) score somewhat poorly in a class known as round-trip efficiency. Using either of them, only about half energy can be pulled out but only half is available due to various changes.
CAES presents an advantage to allow energy to be stored at large scales which is an obstacle for electrochemical battery technologies. Nonetheless, to reach a high round-trip efficiency is a major challenge for traditional CAES.
Meanwhile, for conventional CASE process electrical energy is used to compress air, and the compressed air is stored below ground in a cavern or in a pressurized vessel. On compressing the air, its temperature rises, but the heat is typically considered as waste and thus goes unused.