Alliant Energy is transitioning its power generation portfolio to a more balanced mix of traditional and renewable sources. As part of this initiative, they ceased the coal-fired operations at the Rock River Generating Station in Wisconsin. Part of the decommissioning process included the closure of the coal ash landfill and the decision to install Wisconsin’s first utility-scale solar photovoltaic (PV) system.
Alliant Energy needed to assess if it was technically and economically feasible to install a utility-scale PV system at the site. They also needed assistance navigating state regulations, designing/developing the site, and integrating the PV system installation with the final cover of the ash landfill. The design and installation of the PV system with the final cover system required the team to minimize adverse effects on the performance of the landfill, which included restrictions on burial depths and cap penetrations.
Outcomes and Benefits
The assessment concluded that there was a significant opportunity to install a utility-scale PV system and to generate revenue from otherwise undevelopable land.
The installation of the PV system was the first Wisconsin utility-scale solar installation located on a closed landfill site. It also helped the utility move towards their goal of a more balanced portfolio.
When the facility went into service, it was the largest solar generating station in Wisconsin, producing 2.3 megawatts, enough to power 500 local households.
Alliant Energy’s commitment to net-zero carbon emissions from its electricity by 2050 will reduce carbon emissions by 50% below 2005 levels by 2030 and eliminates all coal-fired power by 2040, 10 years faster than previously planned.