Offshore solar power plants and wind turbines


A partnership that can energise the world 

Floating solar power plants at sea have enormous potential. In between the wind turbines of an offshore wind farm, there are large areas available for solar energy generation. In this way, the energy production of such a sustainable energy power plant at sea may be doubled. Moreover, the electrical infrastructure connecting the power to land can be used more efficiently by making use of the complementarity of wind and solar. After all, when the wind is strong, the sun usually doesn’t shine and sunny days often come with weak wind. 

Within the consortium Solar@Sea II, TNO, Bluewater Energy Services, Genap, Marin, Endures and Avans Hogeschool team-up. The partners will test a concept based on lightweight flexible floaters and flexible solar panels.

Technical improvements

The first idea was to use foam as floater material with lightweight solar panels on top. That worked out technically well but turned out to be too expensive. As a next step, an air mattress was developed and thoroughly tested. Modifications were made accordingly to finally reach the actual status of the design, including water bags for stabilization.  

The continuous development of this novel concept is a good example of teamwork. Genap constructed the floating mattresses. The company has a background in foil applications for the agricultural and infrastructural sectors, and they turned out to be perfectly capable of making the floats for these solar panels. They use advanced materials and fabrication methods to make perfectly flat floaters.  

The mooring was designed and delivered by Bluewater. This company has a background in mooring floating systems in (harsh) offshore conditions. The mooring system which forms a complex spider-like network underwater is a perfect system for mooring multiple floaters without the need to inter-coupling these. 

Practical tests 

To ensure the optimal operation of the floaters, several practical tests were carried out. During the first practical test, a scale model of the concept was tested on wave behaviour in the MARIN basin. The floating construction follows the waves due to the flexible, thin-film solar cells and strong but flexible floats. 

Fouling of the solar modules and floaters is being investigated on a small system located in the harbour of Den Helder, by project partner Endures. The growth of organic material on top and the bottom of the floater and solar panel is continuously monitored.  

At the moment, the field test Solar@Sea II is being carried out in the Green Economy Fieldlab Westvoorne in the Oostvoornse Meer, near the Maasvlakte. With two flexible islands of approximately 100 square metres, the experience can now be gained with the concept in practice. The pilot runs until the summer of 2022. The solar panels that are used are of European manufacture and are made in Sweden by Midsummer and Miasole. 


Bluewater Energy Services, Endures and Avans University of Applied Sciences are all three involved as partners. Bluewater is responsible for anchoring the system and has developed an innovative system for the mechanical interconnection of the floaters. Avans is developing maintenance and recycling strategies for this concept, and Endures is researching (prevention of) organic fouling on the panels and floats. 

At the developing and testing stage of an innovative project of this size, partners are important, as well as TKI Urban Energy and TKI Wind op Zee. “TKI Urban Energy and TKI Wind op Zee's role as a driving force in the cooperation between the business community, universities and developers is important. The Solar@Sea project is a typical TKI project in which a consortium of companies is developing a new concept for floating solar panels for offshore applications." 


This article is part of the series Project in the Spotlight. Discover more projects here.