09 July 2021

The recently launched PV2Float research project focuses on testing photovoltaic power plants on water surfaces.

Solar energy plants on the roofs of houses, industrial buildings or even on large open spaces have already become an integral part of the urban and rural landscape. However, floating solar energy plants, meaning photovoltaic power plants installed on water surfaces, have so far been an exception. This is to change in the future.

Partners from research and industry are working together in the PV2Float joint project. Their goal is to subject floating solar energy plants with different system designs to a practical test over several years. The project team wants to test floating photovoltaics in detail and further develop the underlying technology. The test plants are not only intended to analyse the technical conditions. In the project, the scientists are also looking at acceptance issues as well as economic aspects and ecological impacts of the floating photovoltaic power plants.

Potential for electricity generation and climate protection

Floating PV plants allow the development of new usable areas in order to further promote the expansion of renewable energy sources. They offer a unique advantage compared to conventional photovoltaic systems: Floating solar energy plants do not require any new land areas. They use suitable water surfaces and thus draw on a large power generation potential that is so far rarely explored worldwide. Unlike ground-based plants, the photovoltaic modules are installed on floating bodies. This allows them to be deployed at sea or on standing water, such as surface mine lakes.

Floating PV plants also offer other advantages. Installation on a body of water is associated with a cooling effect for the floating photovoltaic power plants, which in turn enables increased power generation. At the same time, the plants ensure that less water evaporates through the covered or shaded area. The challenge is that the installation and servicing of floating PV plants is more complex. In addition, the use of ecologically safe materials must be taken into account for water protection. The innovative technology nevertheless holds great potential. A current guideline from the Fraunhofer Institute for Solar Energy Systems ISE states that the already installed output of floating photovoltaic plants worldwide is around 2 gigawatts. However, if a quarter of the land destroyed by open-pit mining in Germany alone is flooded and covered with floating PV plants, there is already a technical potential here in the mid-double-digit gigawatt range.

The PV2Float research project is funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) and is scheduled to run for three years. (av)

Example of a possible system design for floating PV. In the PV2Float project, several different designs and substructures are realised on a surface mine lake.

© Fraunhofer ISE

Additional Links

Fraunhofer ISE - Press release PV2Float project 
Floating Photovoltaics - Fraunhofer ISE

Floating photovoltaics

Floating photovoltaics are suitable for a variety of water surfaces, such as lakes and calm sea bays. The systems are installed on floats that are anchored to the bottom of the water body or to the edge of the shore. Since the grid connection point is on land, floating power lines connect the photovoltaic power plant to the power grid. This allows new usable areas to be developed - also in Germany. Flooded open-cast mining areas and gravel pits, for example, are suitable here. In addition, the floating solar plants have other advantages: Installation on a water surface means that the resulting evaporative cooling cools the photovoltaic modules and thus enables higher power production. Furthermore, part of the water surface is shaded, which means that less water evaporates. What is challenging with these photovoltaic systems, however, is that installation and service are more complex. In 2020, their installed capacity worldwide was about two gigawatts.

Among other things, EnArgus, the central information system for energy research funding, contains a database of all energy research projects - including this project.
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