Deltares is working with industrial parties, governments and knowledge partners on quantifying the impact of floating solar on waterbody thermal stratification, chemical composition, and food webs, and therefore on biodiversity under and above floating solar. The goal is to provide tools and guidelines for the energy sector and to allow authorities to design floating solar plants in such a way that they will have a minimal or even positive impact on water quality and biodiversity. This will contribute to Dutch national goals such as improving water quality, a sustainable North Sea and rivers, and renewable energy, as well as to SDG 15.9 on integrating ecosystem and biodiversity values.

Most commercial floating solar plants are currently located on inland waters. That began with small water bodies such as basins in wastewater treatment plants that do not directly impact larger water bodies and nature reserves. Larger, isolated, water bodies such as sand pit lakes have now been selected to accommodate floating solar, providing a living lab for determining the environmental impacts. With private partners (GroenLeven, Ventolines BV, Evides, Indymo) and government authorities (Rijkswaterstaat and regional water managers), we are monitoring the impact of these floating solar panels on water quality parameters. Continuous measurements show that, in the case of several parameters, there is a difference between the situation under the panels and in the open water. Some of the insights are shown in Figure 1.