Vattenfall is to install solar systems at two pumped hydro storage plants at Saxony and Geesthacht in Schleswig-Holstein, Germany.
In Markersbach, the company plans to install solar panels totalling 4.3MW at the dam of the upper basin, while in Geesthacht it plans to install 2.4MW.
Vattenfall will also use roof areas at Markersbach bringing the overall total to 7MW at both facilities.
Construction is scheduled for 2020.
Vattenfall Wasserkraft managing director Peter Apel said: “Vattenfall’s goal is to enable a fossil-free life within one generation.
“Therefore, it is logical for us as a company to continue to expand our renewable energies in the regions where we have been an integral part of the local energy infrastructure for decades with our proven pumped storage technology.”