Floating photovoltaic systems are rapidly expanding globally. In Germany, the current installed capacity of floating PV stands at 21 megawatts (MW), with an additional 62 megawatts either under approval or in construction. However, a new analysis conducted by RWE and the Fraunhofer Institute for Solar Energy Systems ISE reveals that the potential for floating photovoltaic systems in Germany remains significantly underutilized.

The study estimates that, under strict technical, economic, and ecological constraints, Germany’s artificial lakes could accommodate up to 1.8 gigawatts (GW) of peak capacity with south-facing solar modules and up to 2.5 gigawatts with east-west facing modules. This is based on current regulations, which limit the coverage of water bodies to 15 percent and mandate a minimum distance of 40 meters from the shore. The analysis focused on artificial lakes that are not within protected zones, such as nature reserves, and are within 5 kilometers of medium-voltage grid connections.

Graphical representation of the floating PV potential in Germany in compliance with various specifications. | Source: Fraunhofer ISE

Dr. Karolina Baltins, Head of Floating Photovoltaics at Fraunhofer ISE, explains that, "under these conditions, we find a viable potential of 1.8 gigawatts peak for south-facing PV installations and 2.5 gigawatts peak for east-west orientations. The purely technical potential of all artificial lakes, each with a minimum size of one hectare, is even greater. With 15 percent coverage and a 20-meter edge strip, the potential reaches at least 14 gigawatts peak. If 35 percent coverage were allowed, this could rise to up to 45 gigawatts peak."

Cassandra Mpofu, a co-author of the study now at Mailänder Consult GmbH, adds, "Edge strips around water bodies are often unsuitable for floating PV due to shading, vegetation, or shallow depths, which is why they were not included in this conservative estimate."

Germany is home to 6,043 artificial lakes spanning over 90,000 hectares, with the majority located in Saxony and Baden-Württemberg. These include gravel pits, reservoirs, retention basins, dams, and mining lakes. The analysis is part of the “PV2FLOAT” research project, funded by the German Federal Ministry for Economic Affairs and Climate Protection (BMWK), which utilized geoinformation systems to assess the potential of these water bodies.