New Compressed Air Energy Storage Concept Improves the Profitability of Existing Simple Cycle, Combined Cycle, Wind Energy, and Landfill Gas Power Plants

The proposed novel compressed air energy storage (CAES) concept is based on the utilization of capacity reserves of combustion turbine (CT) and combined cycle (CC) plants for the peak power generation, instead of development of highly customized and expensive turbo-machinery trains. These power reserves are particularly high during high ambient temperatures that correspond to typical summer peak power requirements. The stored compressed air will be injected into the CT after the compressor diffuser to supplement the reduced (due to high ambient temperature or altitudes) mass flow, through the turbine to the full potential (typically achieved at low ambient temperatures). The alternative concept, with stored compressed air, is humidification before injection into the CT, this reduces the auxiliary compressor size, the storage volume and associated costs. Power increase of up to 25% can be realized, coincidental with that which is typical for a CAES plant, significant reduction in the heat rate and emissions. The novel CAES concept reduces specific plant costs by a factor of two, which makes it particularly effective for integration with renewable energy sources, like wind energy plants and landfill gas (LFG) plants. The paper also presents an alternative small capacity CAES plant, which is based on using smaller man-made storage facilities (high pressure pipes and/or vessels), either underground or above ground that can be readily constructed at CT sites without specific geological requirements. The latter part of this paper specifically concentrates on integration of CAES with wind and landfill gas (LFG) plants.