© Fraunhofer ISE

Solar systems learn to swim: Research and industry combine to put various systems through several years of practical use.

Floating photovoltaic power plants – so-called floating PV plants – enable the expansion of renewable energies without taking up new land areas. The Fraunhofer Institute for Solar Energy Systems ISE, RWE Renewables and the Brandenburg University of Technology Cottbus-Senftenberg (BTU) want to further develop this innovative technology together with other partners. The aim of the “PV2Float” research project is to subject several floating PV systems with different system designs to intensive practical testing. The research project is scheduled to run for a total of three years. A suitable open pit lake for implementation is currently being selected.

Floating PV on water surfaces harbours a hitherto hardly exploited power generation and climate protection potential worldwide. In contrast to ground-mounted systems, the PV modules are installed on floating bodies and deployed on standing water or the sea. In Germany alone, some 500 opencast lakes have been created as a result of opencast lignite mining. According to a study by Fraunhofer ISE, from a purely technical point of view, these have a usable potential in the mid-double-digit gigawatt range*. Thus, the floating PV plants open up new perspectives for former centres of lignite mining, such as Lusatia.
The “PV2Float” project, which is funded by the German Federal Ministry for Economic Affairs and Energy, aims to help tap this potential. The test plants form an important basis for a precise analysis of the technical requirements, economic efficiency and ecological effects of floating PV power plants in Germany. The focus is also on the question of acceptance.

In addition to the final site selection, RWE is contributing to the project with a comprehensive potential analysis of the German and international market for floating PV. As one of the world’s leading companies in the field of renewable energies, RWE has many years of experience in the construction and operation of ground-mounted solar plants and is currently implementing a floating PV project in the Netherlands.
Thorsten Miltkau, Senior Manager Solar Power at RWE Renewables, explains: “We see great potential for floating PV worldwide. With this research project, we want to deepen our knowledge of the technical possibilities of floating photovoltaic systems, such as scalability and energy yield, and transfer the findings to commercial projects.”

The experimental plant is being designed and built together with Volta Solar. Four floating installations and a reference installation on land with a total output of around 150 kilowatts are planned. Heckert Solar, a solar module manufacturer from Chemnitz, will support the project with innovative module concepts.
VDE Renewables evaluates the power plant concepts developed within the framework of the project with regard to conformity with standards and electrical safety and checks the plants after construction. Fraunhofer ISE is investigating the regulatory framework for floating PV systems and is developing a procedure for the participation of local actors. The institute also checks the reliability of the individual system components, further develops PV modules and yield simulations for the special requirements of the floating application area, and analyzes the economic efficiency of floating PV. Stefan Wieland, head of the project at Fraunhofer ISE, explains: “The body of water places special demands on the design, material, environmental compatibility and operational management of floating PV power plants. The project will investigate these with respect to the construction of large floating PV systems.”
The ecological monitoring of the project is carried out by the BTU Cottbus-Senftenberg and the Institute for Water and Soil Dr. Uhlmann from Dresden.
Dr. Dieter Leßmann from the Chair of Water Protection at the BTU Cottbus-Senftenberg notes: “The ecological compatibility of floating solar plants is a basic prerequisite for their approvability. With the PV2Float research project, we want to further our knowledge of the aquatic ecological effects.”