Hydroelectric power plants that harness 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.
A research team has 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 world's current electricity needs.
Clinic
The analysis was conducted by scientists at the US Department of Energy's National Renewable Energy Laboratory (NREL). The team examined freshwater hydroelectric reservoirs currently installed around the world and their potential to host solar photovoltaic panels floating on the water surface.
These systems could be adapted to allow solar energy generation during the day. Hydroelectric 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 each year, excluding energy from existing hydroelectric plants.
This is a monumental figure, considering that 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 may make them unsuitable for floating PV, but even so the discovery is sensational.
“This is really optimistic,” he says Nathan Lee, lead author of the article. It is an upper estimate of achievable resources that considers the constraints of the water body and the performance of the generation system.”
