The development of a combustion system for a 110 MW CAES plant

The use of stored energy systems is receiving increased attention for power generation. Alabama Electric Co-operative (AEC) have installed a 110 MW Compressed Air Energy Storage (CAES) plant at Mclntosh, Alabama. The plant employs tandem high and low-pressure fired expanders with the high-pressure combustors operating at 44 atm and the low-pressure units at 15 atm. Both are designed to operate with natural gas, or on No. 2 fuel oil, as a standby fuel. This paper describes the development of both the high and low-pressure combustors for this unique application, the testing of prototypes at simulated conditions at up to 8 atm using customized test rigs, and the definition of a design for application to the plant. Problems encountered during the first three years of operation are described and the solutions to overcome these are also presented.