Riverside Energy Center
Riverside Energy Center is a 674.9 MW natural gas combined-cycle power plant in Rock County, Wisconsin, near Beloit, consisting of two combustion turbines and one steam turbine (CTG1, CTG2, STG1) that entered service in June 2004. The plant was built by Calpine Corporation and originally operated as an independent merchant facility before Wisconsin Power & Light Company, a subsidiary of Alliant Energy, closed on its purchase of Riverside Energy Center, LLC from Calpine in January 2013. Wisconsin Power & Light now both owns and operates the plant as part of its regulated generation fleet serving Wisconsin customers. All three generating units remain in active operation with no retirement scheduled. The facility sits within the Midcontinent Independent System Operator (MISO) footprint, consistent with Alliant Energy's balancing authority territory in southern Wisconsin. A separate, newer 650 MW combined-cycle unit known as West Riverside Energy Center was later built adjacent to the original plant and entered service in 2020, but it is a distinct generating facility from the Riverside Energy Center described here.