What it is: Alliant Energy is building a second gas-fired power plant in the town of Beloit. The new plant will be west of the longtime power-generating site, which is along the west bank of the Rock River off Beloit-Rock Townline Road.
About 250 workers are working on the 730-megawatt generating plant on the east side of South Walters Road. When completed, the plant will be able to supply electricity for about 500,000 homes, Alliant says on its website.
The plant will consist of two gas-fired electric turbines, which will be partnered with a steam generator that will collect excess heat to make steam to further power the turbines.
AECON of Los Angeles is the contractor for the $700 million project.
Background: The new plant will join a similar, gas-powered, 675-megawatt plant to the east, which was built in 2004 on a site that the company has used since the 1950s and was once referred to as the Rock River Generating Station.
The 2004 plant replaced older power generation facilities, including two natural gas-fired plants that were converted after using coal for many years. Those plants were retired in 2010. Nearby, the 2.3-megawatt Rock River Solar Facility started producing power in 2016.
The old campus is now called the Alliant Energy Riverside Energy Center. The new plant will be named the West Riverside Energy Center.
The plant’s two gas-fired turbines, when paired the heat-recovery steam generators, are called combined-cycle plants.
Status: On schedule for completion in early 2020, Alliant says.
Work started in August 2016. This year, workers have completed major excavation and site preparation, installed underground well-water laterals, installed above-ground collector well pumps, electrical and piping, and poured the foundation for the heat-recovery steam generator No. 1.
Next steps: Work will continue through this winter, said Alliant spokesman Scott Reigstad.
Parts of the heat recovery steam generator—called modules—are starting to arrive with deliveries scheduled during the day or evenings to avoid traffic problems, Reigstad said.
The construction site also will receive deliveries of sections of a 750-ton crane that will be assembled on site, Reigstad said.
The crane will lift the modules and place them into the casings—the two prominent, box-like structures.
Also starting this month will be earthwork on the new Kittyhawk Substation that is part of the project, opposite the new plant on the west side of Walters Road, Reigstad said.
The future: Alliant plans a West Riverside Solar Facility, generating 2 megawatts, that will supply power to operations at the West Riverside Energy Center. Groundbreaking for the new solar plant will likely take place next year and be completed in early 2020.