Underground coal mine workings as potential places for Compressed Air Energy Storage

The article gives a brief overview of current developments and projects of Compressed Air Energy Storage (CAES). Typical CAES configurations such as Adiabatic CAES and Diabatic CAES are described. The concept of air storage in isolated workings of closed coal mine is presented taking into account availability of such places in the Silesian Coal Basin of southern Poland. The article also discusses major challenges of such concept such as insulation of underground workings, geomechanical stability of workings and site availability. As a proof of concept examples of underground coal mines converted into natural gas storage sites are given. Types of underground workings that could serve as a part of potential compressed storage site are listed and an example of volume calculation available in coal mine for storage is given.