Dispatch flexibility

Dispatch flexibility of a compressed air energy storage (CAES) facility far exceeds that of conventional power generation technologies. Our CAES configuration allows twice the operating range and more than doubles the ramp rate per minute of a combined cycle gas turbine, ERCOT’s primary resource for providing flexibility today. Flexible generation is critical to maintaining grid reliability through periods of volatile demand as well as integrating intermittent wind and solar resources 24 hours a day, 365 days a year.

Low cost

CAES facilities achieve lower dispatch costs than conventional generation by efficiently redeploying inexpensive offpeak power. Offpeak power is used to compress air into an underground cavern, converting electricity into potential energy. The compressed air is released during periods of higher demand, and supplemented with natural gas, to drive expansion turbines and generate electricity. Natural gas consumption associated with CAES is significantly lower than that of a combined cycle gas turbine.

High reliability

Grid operators constantly depend upon flexible generation to maintain reliability. PowerSouth’s McIntosh CAES plant, which also uses Siemens AG compressors and expanders, has demonstrated an exceptional operating reliability over the past 15 years of 99.6% and 97.2% on the compressor and generator, respectively. The Apex CAES configuration, nearly identical to that of McIntosh, aims to match or exceed its predecessor’s track record to ensure that we can provide energy and regulation to ERCOT at the lowest cost possible.

“Storage assets are my #1 tool for maintaining reliability” – Terry Boston CEO of PJM Interconnection, largest transmission organization in the United States

Apex CAES facilities will incorporate time-tested Siemens AG compressors and expanders.