Pairing floating solar photovoltaic (FPV) systems with hydroelectric power stations could boost global power generation capacity by up to 7.6 terawatts from the solar energy contribution alone. An assessment conducted by U.S. National Renewable Energy Laboratory (NREL) researchers indicates that almost 380,000 freshwater hydropower reservoirs worldwide could accommodate combining FPV sites with existing hydropower capacity.

Schematic of a hybrid FPV-hydropower system. Source: NRELSchematic of a hybrid FPV-hydropower system. Source: NRELThe dual generation technology is gaining traction in areas where space for ground-based solar energy systems is limited. Few such combined facilities exist, but the researchers point to the Alto Rabagão pumped-storage reservoir in Portugal, with an installed capacity of 220 solar kW. A 200 kW FPV project is also operational in Suvereto, Italy. About 10% of annual electricity production in the U.S. could be derived by installing floating solar panels on man-made reservoirs.

Floating panels can increase the capacity factor of a hydropower plant by 50% to 100%, and can gain 7% to 14% more energy than a land installation due to the reduction of temperature. The hybrid solar-hydro approach represents a cost-effective strategy for allocating new photovoltaic plants without occupying natural lands, protecting dams from insulation and increasing hydropower generation by reducing evaporation losses.

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