Floating Foundations for Offshore Wind Farms

Briefing

Introduction

Floating wind turbines offer an alternative to the conventional structural foundation on the seabed. The first commercial wind farms with floating foundations are already in operation, e.g. WindFloat Atlantic off the coast of Portugal or Hywind and Kincardine off the coast of Scotland. Other wind farms with significantly higher capacity are in the planning or have already reached the construction stage, such as Hywind Tampen off the coast of Norway. In South Korea, according to current government plans, floating wind farms with a total capacity of 6 GW and an investment volume of around 27 billion Euros are to be built by 2030. Both the United Kingdom and France consider floating wind turbines in their current CfD (Contracts for Difference) tenders. And most recently, at the end of May the US government announced plans for the construction of offshore wind farms with a capacity of 30 GW for which floating foundations are to be used on the Pacific coast. The US Department of Energy is providing around 100 million dollars for their development.

Question: What are the advantages of floating foundations?
Answer: The feasibility of wind turbines founded on the seabed using monopiles, jackets or tripods depends to a large extent on the water depth. As water depth increases, construction becomes technically, logistically and economically more complex and eventually reaches its limits. Floating foundations are free from this restriction. Their installation can therefore take place in areas with the most suitable wind conditions, regardless of the water depth. Especially in regions where, due to the steeply sloping seabed off the coasts, it has not been possible to erect offshore wind farms so far, floating foundations offer completely new possibilities.

Question: What are the challenges of floating foundations?
Answer: The development and construction of floating foundations requires different expertise than the construction of grounded plants, and is comparable, for example, to the construction of floating oil rigs. Moreover, wind turbines to be installed on floating foundations do not have to be erected at sea, but can be largely completed in port and then towed to their destination. This allows for a completely different construction logistics, especially one that is less dependent on weather and ground risks, and requires new ways of thinking and content from both a regulatory and contractual perspective. In this respect, however, it will be possible to draw on existing experience and contractual concepts from shipbuilding and the offshore oil and gas industry for the various project contracts.

Question: What are the long-term development prospects?
Answer: With floating foundations, offshore wind farms are possible at an even greater distance from the coast. However, the greater the distance from the coast, the more complex the connection to the electricity grid. The combination with likewise floating electrolysis plants for hydrogen production lends itself particularly well here. This would enable transport by pipelines, but above all also by ships, with direction connections all over the world. The general possibility of moving floating wind turbines from one location to another could also open up a secondary market that has never existed before, at least in the long term.