Solar Energy: Closed Landfill Solar Power Generating Station, Hanwha QCELLS USA

Rock River Generating Station, Beloit, Wisconsin


solar on landfill
PV System atop landfill cover provides re-use of the land.

After the closure of the coal ash landfill at the Rock River Generating Station, SCS Engineers (SCS) assists the owner of the solar power photovoltaic (PV) system with PV system design and site development of the landfill final cover. The design and construction of the PV system are required to meet the approval conditions from the Wisconsin Department of Natural Resources (WDNR).

Installation of the PV system on the landfill cover system requires that the installation does not have an adverse effect on the performance of the landfill, which includes restrictions on burial depths within the two cover systems. The landfill final cover has two areas, a cover area consisting of topsoil overlying general fill and another cover area where the topsoil and general fill are placed over a geosynthetic clay liner (GCL). The PV system consists of solar panels and racks installed on concrete grade beam foundations placed within the final cover, junction boxes, inverters, electrical conduit, and equipment enclosures.

Outcomes and Benefits
The installation is the first Wisconsin utility-scale solar installation located on a closed landfill site and helped the utility modernize their town of Beloit energy campus. 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.


  • Geotechnical investigation including borings, testing, and data report preparation for PV system design
  • Construction-level bid drawings including drainage and erosion control
  • Assistance with obtaining local approvals
  • Grade table and survey drawing preparation
  • Construction administration
  • Construction surveying
  • Construction observations for the access road and foundation excavations
  • Inspection of erosion control and the stormwater management system
  • Construction documentation report preparation
  • Initial landfill cover inspection after PV system construction