Utility-Scale Solar in the Chicago Metropolitan Area: A Site Suitability Analysis

Abstract

In recent years, renewable energy has expanded in the United States of America (Fernández 2024). Renewable energy has been further incentivized by acts like the Inflation Reduction Act of 2022, which provides tax credits for clean energy projects (Yarmuth 2022). The IRA provides up to an extra 10% tax credit to Energy Communities, census tracts and metropolitan statistical areas designated as being particularly important locations for renewable energy development (Interagency Working Group on Coal & Power Plant Communities & Economic Revitalization, n.d.; U.S. Department of Energy 2024). The Chicago metropolitan area is an Energy Community due to above average unemployment rates and reliance on fossil fuel economies through employment or tax revenues (Interagency Working Group on Coal & Power Plant Communities & Economic Revitalization, n.d.). The bonus tax credit can make siting a solar project in the Chicago Energy Community economically attractive.

A geographic information systems multi-criteria decision analysis was conducted in ESRI ArcGIS Pro software to identify the most suitable locations within the Chicago metropolitan area for a new, utility-scale, ground-mounted solar farm with a capacity of at least 5 MW. Potential locations for development were identified based on slope, zoning and land use, distance to substation, and parcel size. Regions where development cannot occur due to physical characteristics, land use, or electrical infrastructure availability were removed from the area of study. A suitability score on a scale of 0 to 1,000, with higher values corresponding to higher site suitability, was calculated for each potential location using a weighted raster sum with four factors: solar radiation, slope, distance to substation, and parcel size. Site suitability factors were determined based on their ability to impact electricity generation and cost. Geospatial data for the analysis were collected in vector and raster formats from free, open sources, mostly federal, state, and county governments.

Results show 1,721 available land areas with potential for solar energy development. The parcels’ suitability scores range from 608 to 844, with higher values corresponding to more suitable areas. This information can be valuable to utility-scale solar project developers looking to site new solar energy systems.