Hydropower plants that harness the power 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.
A research team carried out an analysis of the energy potential of combining hydroelectric dams with floating solar panels. Result? He calculated that these hybrid plants they could satisfy a "significant" part of the current global electricity needs.
The analysis was conducted by scientists from the US Department of Energy's National Renewable Energy Laboratory (NREL). The team looked at the freshwater hydropower basins currently installed around the world and their potential to host floating photovoltaic solar panels on the water surface.
These systems could be adapted to enable solar power generation during the day. Hydropower dams, on the other hand, store water and energy for use during periods of peak demand (and they would serve us damnably).
Hydroelectric dams and floating solar panels, the pilot project
At present, this type of floating solar / hydro hybrid system has been installed in one location only, as a pilot project in the dam of the Rabagão river in Portugal.
It is comprised of 840 solar panels covering 2.500 square meters (27.000 square feet) and has an estimated power generation capacity of 300 MWh.
Energy supplier EDP plans to expand this pilot project with a system of 11.000 floating solar panels at the Alqueva hydroelectric power plant, one of the largest energy storage facilities in Portugal.
It's only the beginning
According to the new NREL analysis, it's simply a matter of scraping the surface of what these systems could offer. The team estimates there are
nearly 380.000 other hydroelectric power reservoirs around the world that could be equipped with these floating photovoltaic systems, which would connect to existing substations used by dams and hydroelectric power plants. They could produce up to 7,6 TWh of energy per year, or up to 10.600 TWh per year, excluding energy from existing hydroelectric plants.
This is a monumental figure, considering that the electricity demand for the entire globe was just over 22.300 TWh in 2018.
Hydroelectric dams and floating solar panels: now we need a roadmap
The study is much more a way to highlight the potential of this almost non-existent energy solution than a plan to implement it. The researchers say further work would be needed to evaluate the sites. Some may be dry at certain times of the year or there may be other factors that could make them unsuitable for floating PV, but even so the find is sensational.
“This is really optimistic,” he says Nathan Lee, lead author of the article. It is a superior estimate of the achievable resources that considers the constraints of the water body and the performance of the generation system ”.