The Capitol Area System or CAS is a district heating and cooling loop that serves both State and private users in the Capitol area. It consist of two main components, the “loop” which is made up of over 3 miles of underground piping and the central plant. Hot water and chilled water are commodities produced by the plant and pumped into the “loop”.
The plant was originally constructed in 1988 as a combined-cycle cogeneration merchant plant with a nameplate capacity of 62.1 MW capable of dual fuel use. Steam was a by-product of the power generation and used to heat the buildings on the loop or drive an absorption chiller to produce chilled water. As time went on and larger power plants came online the CAS plant was used less frequently and eventually the turbines were shut down and decommissioned. Dual fuel steam boilers were installed to provide heating to the loop when the turbines were not running.