Hydropower plants that leverage the force of falling water to generate electricity are already an important part of the global energy mix, but a new study suggests they may have much more to offer. Scientists have carried out an analysis of the energy potential of combining these facilities with floating solar panels, calculating these hybrid plants could meet a "significant" portion of the world's current electricity needs.

The analysis was carried out by scientists at the US Department of Energy's National Renewable Energy Laboratory (NREL), who looked at the freshwater hydropower reservoirs currently installed across the world and their potential to accommodate floating solar photovoltaic panels on the water's surface. These systems could be retrofitted to allow solar power to be generated during the day, while the hydropower systems store up water and energy for use during peak demand periods.

As it stands, this kind of hybrid floating solar/hydropower system has been installed in only one location, as a pilot project in the dam of Portugal's River Rabagão. It is made up of 840 solar panels covering 2,500 square meters (27,000 sq ft) and has an estimated energy production capacity of 300 MWh. Energy provider EDP is planning to expand on this pilot project with an 11,000-panel floating photovoltaic system at the Alqueva hydro power plant, one of the largest energy storage facilities in Portugal.

According to the new analysis from the NREL, this is very much just scraping the surface of what these systems could offer. The team estimates that there are almost 380,000 other hydropower reservoirs around the world that could be fitted with these floating photovoltaic systems.