Advancing Sustainability by Exploring Rooftop Solar Potential at UW–Madison

Burning fossil fuels like natural gas, oil, and coal is the largest contributor to the climate crisis. We now frequently hear calls to transition our energy systems away from fossil fuels and towards clean and renewable energy.

There is strong potential to expand renewable energy in Wisconsin, which supplies only 11 percent of our electricity demand. Here at UW–Madison, students are using state-of-the-art data and modeling software to explore a great opportunity to advance campus sustainability goals: rooftop solar.

Placing solar panels on roof-tops could be a “low-hanging fruit” climate solution. It may be a cost-effective and practical way to increase renewable electricity generation because the economics and efficiency of solar panels have improved significantly over the last decade. Adding solar to on-campus facilities contributes to our institutional mission by offering a visible learning and research opportunity while demonstrating a commitment to sustainability.

Student Jon Starfeldt (atmospheric and oceanic sciences, data science), a member of the HELIOS student organization, talks at the UW–Madison Sustainability Symposium in 2023 about campus rooftop solar potential. Photo by Bryce Richter, University Communications

The UW–Madison Office of Sustainability is working with the Climate Action Lab and student organizations Helios and Campus Leaders for Energy Action Now (CLEAN) to investigate rooftop solar potential on our main campus.

Our team selected buildings with a variety of functions and locations to illustrate how rooftop solar could offer visible learning and research opportunities while contributing to campus sustainability goals. Our team used a recently launched commercial tool, the Google Solar API, to conduct a comprehensive assessment of each viable campus building.

The first stage of the analysis was to better understand the technical potential of rooftop solar on campus. Our team selected 197 buildings with approximately 5 million square feet of rooftops for the initial phase of the study.

From a technical perspective, we found that rooftop solar installation could produce between 15 and 24 percent of the electricity used at UW–Madison’s campus. Additional research will be needed to evaluate investment requirements and benefits and to prioritize locations for rooftop solar.

Map of UW–Madison campus buildings considered for solar assessment. The color and size of bubbles are located at the address coordinates of each building and represent the annual solar power output in AC MWh. Image courtesy of the authors

The initial findings show that increasing the share of solar at UW–Madison is a viable option to help achieve sustainability goals on campus and beyond. The Google Solar API uses satellite data on solar irradiation, weather, shading, and rooftop orientation coupled with machine learning algorithms to estimate the solar energy potential of individual buildings.

Large buildings such as the Kohl Center, Union South, and Grainger Hall (Wisconsin School of Business), have the largest potential, though technical barriers must be explored to determine the feasibility of adding solar.

The Google Solar API covers most buildings in the U.S., meaning that other communities can use it to explore rooftop solar energy and accelerate their transition to renewable energy.

Author Affiliations

  • Jaime Garibay-Rodriguez, UW–Madison La Follette School of Public Affairs, Nelson Institute Center for Sustainability and the Global Environment (SAGE), and Office of Sustainability postdoctoral research associate, garibayrodri@wisc.edu
  • Josh Arnold, UW–Madison Office of Sustainability campus energy coordinator, arnold@wisc.edu
  • Morgan R. Edwards, La Follette School of Public Affairs assistant professor and SAGE researcher, edwards@wisc.edu