Evaluating Potential Land Use of Utility-Scale Photovoltaics (Solar Panels) on Farmland in Tennessee

Photovoltaic (PV) cells, commonly referred to as solar panels, absorb energy from sunlight and convert it to electricity. PV energy generation has increased drastically in the United States (U.S.) in the last decade, growing from 26.5 gigawatt-hours in 2014 to over 207 gigawatt-hours in the last 12 months, or from 0.6% to 4.8% of total U.S. electricity production (U.S. Energy Information Administration, 2023a). The combination of increasing cost competitiveness of PV energy generation (U.S. Department of Energy [DOE], 2021) and efforts to decarbonize the U.S. electric grid suggest even more rapid growth. For example, the U.S. DOE (2021) projects that solar generation could grow to as much as 40% of the U.S. electricity supply by 2035, given aggressive decarbonization policies. At a more local level, the Tennessee Valley Authority (TVA) has set a goal of adding 10 gigawatts (GWs) of solar production capacity from 2022 to 2035 (Tennessee Valley Authority, 2023b). The rapid production growth coupled with aggressive targets for decarbonization and increased solar capacity has focused attention on the amount of land currently being converted to PV energy production and the amount that will ultimately be needed to accommodate future growth. This report attempts to quantify the amount of land currently used for utility-scale PV energy production in Tennessee and to project the amount likely to be used under different scenarios for future growth. More specifically, this report estimates the amount of land in Tennessee used by: (i) existing utility-scale PV production, (ii) contracted but not yet operational utility-scale PV production, and (iii) utility-scale PV production if TVA were to reach its PV electricity generation goals. Given that farmland could be a location of PV electricity production, the report considers the possible effects of growth on the amount of available farmland in Tennessee. In Tennessee, operational utility-scale PV production currently produces 344 megawatts (MWs) of energy (TVA, 2023a). Contracted, but not yet operational, utility-scale PV production in Tennessee will account for another 1,130 MWs of energy (TVA, 2023a). Following industry and academic literature (e.g., Solar Energy Industries Association, 2023; Bolinger and Bolinger 2022), a range of 5.56 to 10 acres per MW of generated power was used to estimate PV land use. Thus, current operational and contracted utility-scale PV facilities in Tennessee would generate 1,474 MWs of energy and require 8,197 to 14,743 acres of land. Tennessee has 26.4 million acres of land and 10.8 million acres of farmland (USDA, 2023). Therefore, operational and contracted utility-scale PV land use equates to 0.031 to 0.056% of Tennessee’s total landmass or 0.076 to 0.137% of Tennessee’s farmland if all these facilities were located on farmland. If by 2035 TVA reached their sustainability goal and added an additional 10 GWs of PV generation to the existing 344 MWs of PV production in Tennessee, and assuming that TVA placed all PV developments in Tennessee, 57,514 to 103,443 acres of land would be required for utility-scale PV installments (i.e., an amount equivalent to 0.22 to 0.39% of Tennessee land or 0.53 to 0.96% of Tennessee farmland if exclusively placed on farmland). However, not all of this additional production would be located in Tennessee, which occupies a little more than half of TVA’s 80,000 square mile service region. To provide greater context, this report also contains information on the location of existing and contracted utility-scale PV developments, the extent of Tennessee farmland being converted to other uses, PV development considerations for agricultural communities, and the potential for collocation of PV power generation and agricultural production, or what is commonly referred to as agrivoltaics.