Tunnel Hill Solar is a 1,050 acre, 150 MWAC solar PV facility located near Vienna, Illinois.

The project site will use agriculture land that is currently farmed for various crops that was acquired under long-term lease agreements for solar electricity power generation with multiple landowners. All local permitting is completed to construct and operate this project, and the environmental permitting and studies are underway. All required environmental studies are in progress, including a wetlands delineation, a threatened and endangered species review, and a cultural, archaeological, and historical review of the entire site. A topographical study and ALTA survey of the entire site was also completed.

The project will use bi-facial solar modules with high efficiency PV cells that are optimized for utility scale solar photovoltaic projects. Central inverters will minimize operations and maintenance costs and improve efficiency of the overall plant. The modules will be mounted to a single-axis tracking systems that is optimized for use with bi-facial panels to increase the system’s capacity factor.

The project will interconnect to Ameren’s 345 kV transmission system that passes west of the site. The project filed an interconnection application with MISO in 2021 (Queue Position J2156) and expects to sign its Generator Interconnection Agreement late 2025.

Tunnel Hill Solar has an expected Commercial Operations Date in late 2027 or early 2028.