Compressed Air Storage With Humidification: An Economic Analysis Free

A large, 530 MW, Compressed Air Storage with Humidification (CASH) cycle was configured as an energy-storage plant utilizing as the low pressure expander the turbine of the Siemens-Westinghouse W 501F2 with a firing temperature of about 2400°F (1315C) and a 1600°F (870C) high pressure Dresser turbine. A selling price for electricity was developed for this CASH plant and compared with that for power produced by simple and combined cycle power plants of similar size. At 90°F ambient, where cycling power is most necessary, the specific capital cost of the CASH plant was calculated to be 405 $/kW while the simple and combined cycle were 403 and 489 $/kW respectively. The CASH plant has a much lower incremental cost than does the simple cycle. These factors result in the CASH plant having lower overall costs than the simple cycle for operation of over about 400 hr/yr. and lower than the combined cycle for operation of less than about 4000 hr/yr.