Hydropower plants that use the power of falling water to generate electricity are already an important part of the global energy structure, but a new study suggests they may have more to contribute. Scientists analyzed the energy potential of these facilities combined with floating solar panels to calculate the “important” part of these hybrid plants that can meet the world’s current electricity needs.
The analysis was conducted by scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), who studied freshwater hydroelectric reservoirs currently installed around the world and their potential to hold floating solar photovoltaic panels on the surface of the water. These systems can be retrofitted to allow solar power to generate electricity during the day, while hydropower systems store water and energy for peak demand.
Currently, this hybrid floating solar/hydropower system has been installed in only one location and is a pilot project for the Rabagan River Dam in Portugal. It consists of 840 solar panels and covers an area of 2,500 square meters (27,000 square feet) with an estimated energy production capacity of 300 MW. Energy supplier EDP is planning to build on the pilot project to expand an 11,000-panel floating photovoltaic system at the Alqueva hydroelectric power station, one of Portugal’s largest energy storage facilities.
According to NREL’s new analysis, this is largely just the surface these systems can provide. The team estimates that nearly 380,000 hydroelectric reservoirs around the world could be fitted with these floating photovoltaic systems.
These existing substations, which will be connected to hydropower stations, can generate up to 7.6 TW of electricity per year, or up to 10,600 TWh per year, not including energy from existing hydropower facilities. That’s a huge number considering that the world’s electricity demand will be just over 22,300 TWh in 2018, the researchers said.
The study is more about highlighting the potential of this virtually non-existent energy solution than about implementing its roadmap. The researchers say further work is needed to assess these sites, as some sites may be dry at some point during the year, or there may be other factors that make them unsuitable for floating photovoltaics, but even as ball-based numbers, the findings are promising.