SHARING SUNLIGHT: ECOSYSTEM ECOLOGY OF MULTI-USE SOLAR ENERGY SYSTEMS IN THE SOUTHEASTERN U.S.

Abstract

Solar photovoltaic (PV) energy generation is one of the most impactful strategies for reducing global greenhouse gas emissions and mitigating climate change. However, compared to fossil-based energy sources, solar PV has a significantly higher spatial footprint and is often sited on agricultural lands, raising concerns about environmental impact and agricultural displacement. This has spurred the emergence of multi-use solar PV systems, where agriculture (agrivoltaics) or ecosystem services (ecovoltaics) are integrated with solar energy generation on the same piece of land. These systems have the potential to increase land-use efficiency, improve the environmental outcomes of large-scale solar deployment, and provide a range of co-benefits. This dissertation presents an evaluation of the ecological impacts of solar PV systems in the southeastern United States, a geographic and climatic region underrepresented in previous research. The results of three field studies at operational PV arrays across the southeastern U.S. highlight the potential for multi-use solar PV in this region. Data from these sites show minimal effects from low-impact array construction methods, including avoiding grading and retaining vegetation cover, the potential to maintain vegetation and agricultural productivity, despite the reduction in solar radiation and redistribution of precipitation from the PV modules, and no evidence of negative impacts on soil carbon stocks. This work emphasizes the influence of both climate region and site-specific variables, including array geometry, tracking algorithm, and soil texture, and the importance of considering these factors in both research and practice.