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Federally controlled reservoirs hold between 861 GW and 1,042 GW of potential floating solar generating capacity, and it is well distributed across the U.S., according to a new study from the National Renewable Energy Laboratory. Federally controlled reservoirs in the United States have “vast” potential for floating solar generating capacity, ranging from an estimated 861 GW to 1,042 GW, the National Renewable Energy Laboratory (NREL) says in a new study. These estimates could generate about half of the solar power needed to decarbonize the U.S. power grid by 2050, NREL says. While this range is consistent with previous studies attempts to quantify floating solar potential, the study found that the wide variability in reservoir suitability for floating solar development is based on site-specific factors in the U.S. According to the researchers, the study helps to better understand not only how much floating solar capacity may be available, but also where this capacity is most likely to be built. The potential for floating solar is large, but not evenly distributed across the U.S., they say. The research assessed the development potential of floating solar energy solely from the point of view of technical feasibility. Other constraints, such as economic and regulatory ones, were not taken into account in the research. Researchers outlined a novel geospatial method for assessing the potential of floating solar using technology-specific factors on federally owned and regulated U.S. reservoirs. Even under the most conservative scenario for federally owned and regulated reservoirs, the researchers said floating solar has an estimated potential that is more than half of the estimated solar capacity needed for a decarbonized U.S. power grid in 2050. While the study found a wide range of estimated potential system sizes, the majority (57%) are between 10 MW and 1 GW in size, with a median of 123 MW. In what the researchers consider a “conservative scenario,” Texas contains about 16% of the country’s total floating solar capacity. Floating solar potential is well distributed across the U.S. (excluding areas where potential reservoirs were too cold to be considered). The researchers found that states in the Southeast and Southern Plains tend to have the largest reservoir capacities. The United States has more floating solar potential than any other country in the world, according to a study published in Nature Sustainability in March 2023. Interest in floating solar is on the rise, especially since Congressmen Paul Tonko, D-N.Y., and Jared Huffman, D-Calif., introduced the “Protect Our Waters and Expand Renewables in Our Reservoirs Act” in December 2022. Driven by rising demand, lower capital expenditure, and supportive low-carbon energy policies, the United States is on track to install 0.7 GW of floating solar by 2033. Globally, the floating solar market will reach 77 GW of installed capacity by 2033, according to an analysis published in November 2024 by Wood Mackenzie. Due to longer commercial timeframes, Wood Mackenzie expects peak installed capacity for these projects to occur between 2026 and 2028. Floating systems have many advantages, including the use of water instead of land and potential synergies with hydroelectric plants. Floating solar can operate wherever there is a body of water, so it can be located next to existing hydroelectric plants and pumped storage hydroelectric reservoirs. This allows the two types of generation sources to share infrastructure, which NREL says increases energy output and can reduce costs. Floating solar systems emit around 50 grams of CO2 per kWh of electricity generated, which is around seven times less than the current electricity mix in Germany and three to four times less than the EU target for 2030, according to the International Energy Agencys Photovoltaic Power Systems Programme (IEA-PVPS). Compared to ground-mounted solar systems, floating solar also has higher panel efficiency due to environmental cooling effects and low shading. The systems require much less land than ground-mounted systems, and reduce the need for land clearing, evacuation, and grading for site preparation. As the global market for floating solar power takes off, NREL researchers say efforts to understand the technologys role in future energy systems are still in their early stages. The technology faces its own technical and engineering limitations, such as problems posed by currents and ice floes, the researchers say. The study, “ Floating photovoltaic technical potential: A novel geospatial approach on federally controlled reservoirs in the United States,” will be published in the upcoming February issue of Solar Energy . The study was funded by the Solar Energy Technology Office and the Water Energy Technology Office of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy. |
