More than 12,000 solar panels covering an area equivalent to four football pitches are now being laid on the water in a hydroelectric dam in Portugal.
Once all panels will be in place in July, they'll generate 7.5 GWh annually. That's enough to provide 1,500 families with all the electricity they need.
An advantage of laying the panels on the water is that they do not take up land that could be used for other purposes. By installing them in a hydroelectric dam, it's straightforward and cheap to connect the panels to the mains, reducing the total cost.
Another advantage of having the panels in a hydro dam is that the electricity they generate can be used to pump water into the reservoir when the electricity is not needed elsewhere. In this way, the water in the reservoir can be used as a battery.
EDP, the energy company that owns the hydro plant and the solar plant, also intends to go further and build more solar plants in hydro plant dams. The company sees the facilities as a method to help EDP reach the goal of becoming completely fossil-free by 2030.