“Pioneering” – our legal team analysed offshore wind + floating solar for the EU


Windturbines op zee gecombineerd met floating solar

An offshore wind farm combined with floating solar panels is ultra sustainable, commercially interesting and more likely to win a tender. What are the legal and financial implications, though? This is precisely what we analysed for United, an EU-funded project. Today we invite junior legal counsel Pelle van den Heuvel to present a preview of our findings.

Executive summary

  • Ventolines analysed the legal aspects of floating solar panels at sea.
  • We did this for United, an EU-funded project.
  • Our legal team examined the legal possibilities for six scenarios.
  • Greenfield scenarios are particularly promising: solar panels for new wind farms.

Offshore wind + solar for increased tender success

Offshore wind farms with floating solar panels are rapidly gaining popularity. This is understandable, as it is a more efficient and therefore more sustainable use of offshore space. This is also reflected in the regulations for wind farm tenders. Initiators are more likely to win a tender if they install a solar farm next to the wind farm.

Combining rather than competing

This combination of functions is therefore the focus of the research project for which we are doing this legal and financial analysis. United: the name says it all. The objective of this project is to combine activities that currently compete for space out at sea. Pilot projects are therefore being developed in European sea areas in several countries, with the objective of ‘ocean multi-use’.

Co-funded by the EU

The pilots aim to increase sustainability and use existing resources more efficiently to develop commercially interesting business cases. United is partly funded by Horizon 2020, the European Union’s vast research and innovation programme.

Pelle van den Heuvel, one of our junior legal counsels

The publication of our analysis for this project is scheduled for November 2023. Today we invite Pelle van den Heuvel, junior legal counsel at Ventolines, to give us a preview: “In the field of renewable energy, things are developing so rapidly that it is important to assess the regulatory frameworks being developed by the government and how they would be implemented in practice. After all, you can draft legislation endlessly. In practice, however, it will still be different from how it was conceived on paper.”

The Offshore Wind Energy Act

“For this project, Ventolines analysed the contractual aspects and environmental legislation implications of the combination of offshore wind and floating solar. Wind farms are, after all, regulated by the Offshore Wind Energy Act. Yet this act only regulates windmills. What is the legal procedure if you add floating solar farms to a wind farm?”

Ecological aspects of offshore floating solar panels

“This is why the solar farm requires a separate water permit,” Van den Heuvel explains: “The water permit includes ecological requirements, among other aspects, and this is where floating solar differs from a wind farm, since the PV panels cover the water. This can cause algae formation, for example, which must be taken into account during development. By arranging the panels accordingly, sufficient sunlight still reaches the water.”

Six scenarios for solar panels at sea

“Our legal and finance experts developed six scenarios. One could be eliminated right away. That is the stand-alone option in which the solar farm connects independently to a TenneT substation. That is not possible based on current regulations. Then there is a semi-stand-alone option, where the solar farm connects to the wind farm’s cabling. In the third scenario, you connect the solar farm to one or more wind turbines.”

“The leading opportunity for floating solar panels at sea is the connection to a wind farm that is still under development or construction.”
– Pelle van den Heuvel, junior legal counsel Ventolines

Greenfield versus brownfield sites

“Those three different scenarios can again be divided into ‘greenfield’ and ‘brownfield,’ where brownfield refers to an existing wind farm. Greenfield involves a projected new wind farm.”

“Our analysis indicates that the main opportunity is to connect the solar farm to the wind farm. It’s an interesting legal possibility,” says Pelle van den Heuvel, “because the wind farm has the contract with TenneT and is connected to the offshore grid managed by TenneT. The solar farm depends on the agreements between those two parties.”

Connecting floating solar panels to existing wind farms

Connecting floating solar panels to existing wind farms in the North Sea is virtually impossible, explains Van den Heuvel, for financial reasons: “The wind farm will already have signed a contract with TenneT and concluded agreements with funders. For those parties, the sudden addition of a solar farm poses a risk.”

Greenfield scenarios are most promising

Greenfield scenarios are therefore the most promising, according to Pelle van den Heuvel: “The wind farm is then still under development and agreements about solar panels can still be made.”

“Legislation follows technology. In this sector, where technological developments are progressing rapidly, you are always pioneering.”
– Pelle van den Heuvel, junior legal counsel Ventolines

Leading the market

The knowledge we have gained gives us an edge in the market, which our clients are already benefiting from. Pelle van den Heuvel: “We have been working on this project since 2020. Since that time, we have been closely following all developments in the legal, financing and technological fields. Consequently, we know everything about the regulations as well as the reasoning behind them. This is expertise that is fundamental to winning tenders. Ventolines is now running projects in which we are already applying that knowledge.”

Always pioneering

“That’s precisely what I find so interesting about the legal profession. Legislation follows technology. You always begin with an invention before regulations emerge. If you work in areas like sustainability, where technological developments are booming, you’re essentially always pioneering.

Meet Ventolines

Make the most of our legal expertise – get in touch with us to exchange views on your and our ambitions in green energy, whether offshore, nearshore or onshore. Email one of our experts, or call Ventolines. A brief videoconference to get acquainted is also available.

Pelle van den Heuvel
Junior legal counsel

Want to learn more about the United project?


Ventolines has the expertise to direct all aspects of your renewable energy project, from feasibility study to construction, and from contracting to asset management. For the project on this page it involved:

Legal advice
on all aspects
of new energy

Financial advice
for optimal financing

Maximum return from
energy contracts

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