Click the link to access the report on the NREL website (Aaron Levine, Taylor L. Curtis, Ligia E.P. Smith, and Katie DeRose). Here’s the executive summary:
June 2024
Executive Summary
To meet the nation’s decarbonization goals, the U.S. Department of Energy’s Solar Futures study forecasts that installed solar photovoltaic (PV) capacity must increase nearly tenfold, from 80 gigawatts (GW) in 2020 to approximately 760 GW cumulative installed capacity by 2035 (DOE 2021). Ground-mounted PV is expected to dominate future solar deployment and will require more than 3.5 million acres of land to meet annual demand projections (of nearly 45 GW) by 2030 (DOE 2021). However, various competing demands for land (e.g., agricultural production, conservation) and high land acquisition costs in specific locations could be challenges to meeting future PV demand solely with ground-mounted PV deployment (Wood MacKenzie 2023; DOE 2021; Oliveira-Pinto and Stokkermans 2020). Floating photovoltaics (FPV) may be an alternative in locations where ground-mounted PV is not feasible and aid in reaching the nation’s PV deployment and decarbonization goals (DOE 2021; Oliveira-Pinto and Stokkermans 2020; Hooper, Armstrong, and Vlaswinkel 2020; Gallucci 2019).
FPV is a newer siting approach in which a PV array is affixed to a floating apparatus and sited on a water body like a reservoir behind a dam. FPV systems may be stand-alone or co-located a new or existing hydroelectric facilities or pumped storage hydropower (PSH) facility reservoirs. Co-located FPV systems may or may not be operationally paired and work in tandem with the hydroelectric or PSH facility (Gadzanku and Lee 2022; Gadzanku et al. 2021a, 2021b; Lee et al. 2020; Oliveira-Pinto and Stokkermans 2020; Spencer et al. 2018).
Although FPV deployment in the United States is nascent with less than 30 projects installed, significant potential has been identified at existing U.S. reservoirs (Chopra and Garasa Sagardoy 2022). A 2018 National Renewable Energy Laboratory (NREL) study identified more than 24,000 manmade reservoirs (with a total surface area of more than 2 million hectares) in the United States with technical FPV potential; the largest opportunities were found at reservoirs owned by the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation). The NREL study estimated that, if fully realized, FPV systems on U.S. water bodies could have produce almost 10% of the nation’s electricity generation in 2018 (approximately 786 terawatt-hours) (Spencer et al. 2018). A follow-on study completed by NREL in 2024 identified between 861 GW and 1,042 GW (corresponding to 1,221 terawatt- hours and 1,476 terawatt-hours) of technical resource potential across USACE, Reclamation, and Federal Energy Regulatory Commission (FERC)-licensed reservoirs.
Current U.S. domestic FPV development is mostly limited to small-scale projects of less than 1 megawatt (MW) sited on closed-loop water bodies such as wastewater treatment plants, drinking water ponds, and irrigation water storage ponds (Chopra and Garasa Sagardoy 2022). Nevertheless, the versatility, potential benefits, and resource potential of FPV have led to growing investment in recent years, which is expected to continue as PV developers look to alternatives like FPV to meet growing demand (Wood MacKenzie 2023; Chopra and Garasa Sagardoy 2022).
This report provides novel analysis to understand the opportunities and challenges associated with developing stand-alone and co-located FPV projects on Reclamation reservoirs, USACE reservoirs, and FERC-licensed reservoirs in the United States. Specifically, the report explores potential environmental and energy benefits and environmental impacts associated with the siting, construction, and operation of FPV projects. The report also identifies and analyzes U.S. federal- and state-issued permits and authorizations required by federal laws to understand the licensing pathways and regulatory requirements for FPV projects sited on FERC-licensed reservoirs, Reclamation-powered and non-powered reservoirs, and USACE powered and non- powered reservoirs.
Of note, this report only analyzes the addition of FPV to reservoirs and does not consider FPV development on or above canal systems.