ASSESSING COMPRESSED AIR ENERGY STORAGE (CAES) POTENTIAL IN KENTUCKY TO AUGMENT ENERGY PRODUCTION FROM RENEWABLE RESOURCES

Kentucky’s coal-fired electrical generating plants have some of the highest greenhouse gas emissions in the US. One way to mitigate greenhouse gas emissions would be co-installation of Compressed Air Energy Storage (CAES) with renewable photovoltaic (PV) solar generation. The advantage of CAES with PV solar generation is that it is available at night to supplement electricity stored in batteries or capacitors. CAES employed by two existing CAES plants stores compressed air in solution-mined salt caverns to drive power-generation turbines and uses natural gas heat to prepare air for compression. Renewable-sourced electricity can provide the heat for the CAES powerplant and offset burning fossil fuels. Thick salt deposits, however, are not a part of Kentucky’s geology, but there are options for compressed air storage: inactive or abandoned limestone mines; depleted oil and gas fields; aquifers; non-geologic cased wellbores; and advanced compressed air storage in mined caverns. Ten inactive or abandoned limestone mines have been identified as well as four regions where PV solar could be deployed with the different storage models: western Kentucky has abandoned oil and gas fields and confined saline aquifers that may be used for compressed air storage; central and eastern Kentucky has four areas with abandoned oil and gas fields in the Knox Group; in central and northern Kentucky advanced energy storage mines and acid-solution caverns could be constructed; and in eastern Kentucky cased-wellbore compressed air storage on mined-out coal lands may be possible. Thus there are many options for carbon-neutral electrical power generation available in Kentucky.