Apex Compressed Air Energy Storage, LLC, founded in 2011, develops, constructs, owns and operates diabatic compressed air energy storage (CAES) plants. CAES is a proven power storage and generation technology.

Apex CAES uses Siemens Equipment. Their upcoming project, the Bethel Energy Center, will utilize Siemens AG compressors and expanders. Siemens is currently the only provider of complete, integrated utility-scale CAES systems in the world.

Apex CAES is not a technology supplier, it is a project developer using Siemens AG' Smartcaes equipment.

Flexibility and operating range:

• Generator can reach full load within 10 minutes from a cold start
• Independent operation of compressor and generator provides dispatch optionality
• Apex CAES states they have a low sustainable load (LSL) rating of 10% of plant output provides for a 90% operating range (a typical combined cycle gas turbine has an LSL rating of 50% of plant output).

Experience / Reliability:

• PowerSouth’s McIntosh CAES plant - second commercial CAES plant in the world-, which also uses Siemens compressors and expanders, has demonstrated operating reliability over the past 15 years.

Environmental attributes:

• CAES energy production results in 40% fewer emissions per MWh than a combined cycle gas turbine, and its ancillary service production yields 98% fewer emissions per MWh

• Small surface footprints - 10 acres for a 324 MW plant

Replacement or repurposing CCGTs

Diabatic CAES systems consume significantly less natural gas than a combined cycle gas turbine, resulting in fewer emissions and lower operating costs

Long duration storage solution & increased lifetime

Long storage duration of 48 hours - nearly 16,000 MWh.

CAES operating life of more than 30 years is three times that of a lithium-ion battery, resulting in lower LCOS.