Innovative Offshore Wind Power Foundations: Gravity-Based & Floating Wind Turbines

At Bygging Uddemann we specialize in the serial production of concrete structures for offshore wind power foundations. Our expertise lies in the design and construction of Hull, Spar, Semisubmersibles, and Gravity-Based Foundations (GBF).

Open seas are the ideal place to establish wind turbines.

Around 80% of the world’s offshore wind resource potential is in waters deeper than 60 metres. But building wind turbines fixed to the seafloor in deep waters is a complex process. The best way to overcome the difficulty is to set up floating wind turbines.

We can help you utilize the potential of floating wind turbines due to the construction of the floating foundations being quite suitable for the slipform technique. We can offer both our heavy-duty slipform system (for small scale projects) and our gantry slipform system (for larger scale projects). Both systems can be combined with our IP-CCV Transfer System which will provide any contractor with a one packet solution for the construction of foundations.

Why we need floating wind power?

  • Floating wind turbines elevate wind power effectiveness and increase the number of turbines, advancing renewable energy solutions.
  • Floating wind power is crucial for reducing emissions in regions like India, China, and South-East Asia, where renewable energy solutions are needed on a large scale as alternatives to coal.
  • Construction challenges hinder the establishment of wind turbines in areas with powerful winds, distant from urban centers or lacking sufficient space.
  • Floating wind power provides a solution by tapping into stronger and more consistent winds further offshore.
  • Embracing floating wind power is pivotal in achieving the goal of reducing carbon emissions and advancing renewable energy solutions.

How does a floating windmill work?

The floating windmill is often referred to as third-generation wind power. Where the first-generation are the one’s on land, and the second-generation is constructed in the ocean, fixed to the seafloor.

A floating wind turbine looks like a traditional wind turbine but is constructed on a floating fundament. To keep the wind turbine from toppling over, the floating fundament utilizes the iceberg principle, where the majority of the structure is under-water.

Build towards the future with Bygging-Uddemann

One of our targets for the future is to contribute to creating sustainable, resistant, and including infrastructures. We believe that the floating wind turbine is a pioneering solution and a really big leap towards that goal. Contact Bygging-Uddemann today for more information about how we can become your partner for the construction and establishment of floating wind power solutions.


What is a Gravity Based Foundation (GBF)?

As the name suggests, a gravity-based foundation is a structure based on gravity, for facilities in a marine environment. The science behind it is that it uses gravity to hold the plant and the lifting force to make it float. The structure’s own weight helps to withstand lateral forces.

Common applications are oil platforms and offshore wind power. The conditions for gravity-based foundations are that the sea depth is at least 20 meters and that the seabed is sufficiently stable to withstand the pressure in the vertical direction.

Gravity-based platforms are usually made of concrete. They are robust and withstand harsh weather conditions at sea, and have proven to be a suitable choice even in Arctic environments.

With that said, there are certain requirements to consider when choosing concrete: the concrete must be able to withstand forces of up to 100MPa, be resistant to chloride and sulphate ions and in some climates, cope with stresses from ice formation and melting.

Installation of a gravity-based foundation

A challenge during construction and installation is the size of the facility, and that it must be designed to withstand large forces of nature. Material quality is therefore of the utmost importance.

The concrete bottom of the structure is built in a dry dock. Most requirements need to be placed on the dry dock to ensure its suitability. Examples of requirements are sufficient depth, taking into account the size of the base, the design of the base, the bearing capacity of the dock, its drainage system and its bottom material if the gravity-based foundation is placed directly on the bottom. The dry dock must also be waterproof, but have an openable exit so that the foundation can be towed out. It must therefore withstand enormous forces from all over the sea.

It is then transported out to a protected deep port, where it is moored. Thereafter, the towers are created by slipform casting in a continuous process.

The weights are then removed and the whole structure is towed out to the installation site using tug boats. Once there, ballast is placed to secure the foundation to the seabed.

Offshore wind power with gravity-based structure

Structures based on gravity for offshore wind turbines have been shown to have several advantages compared to the alternatives. In cases where the seabed is not sufficiently stable, however, other methods are preferred, such as different types of piling.

Two factors that speak for gravity-based structures over the alternatives are the environmental impact and the economic aspect. Since no piles need to be installed, the impact on the seabed is reduced, as is the noise level during installation. Mounting steel piles causes higher noise levels that can disturb the sea fauna. Concrete that is often used for the base is also a relatively cheap material. It can be used in deep water without any problems. Steel piles require larger diameters with increased water depth, which further contributes to the cost.

When building wind turbines of this structure, however, there are some challenges to take into account. Above all, it is important to be able to produce a construction that resists cyclic forces, ie forces that vary over time, which naturally gives more wear than static forces. These forces come from natural variations in wind speed and wave energy.

Offshore wind turbines with gravity-based construction are currently located in Sweden, Finland, Norway, Belgium and Germany in Europe and interest is growing in several parts of the world.

Maintenance of offshore wind power

Most offshore wind power plants built with gravity-based foundations are made of concrete. This has the great advantage that they require very little maintenance compared to, for example, metal constructions. Steel structures also have a shorter service life and need to be replaced more often. Concrete is a material that has less impact on the environment – when concrete structures need to be replaced after 20-50 years, the old ones can easily be recycled.

In summary, gravity-based constructions have several advantages over traditional piling methods: less environmental impact on the seabed, less noise that disturbs underwater life during installation, materials that require very little maintenance and withstand the test of time, lower material costs, flexibility in size – everything from huge oil platforms to wind turbines can be built according to this method – as well as the possibility to install in varying temperature conditions and climates. Wind power companies with offshore wind power thus have much to gain from switching to gravity-based technology in cases where it is possible.

What are floating wind turbines, and why are they important in the realm of renewable energy solutions?

Floating wind turbines are offshore wind turbines constructed on floating foundations instead of being fixed to the seabed. They are crucial for expanding renewable energy solutions because they enable tapping into wind resources in deep waters, where traditional fixed turbines are impractical. This advancement allows for more efficient utilization of wind power and facilitates the deployment of turbines in areas with powerful winds far from land.

How does Bygging Uddemann contribute to the construction and establishment of floating wind power solutions?

Bygging Uddemann specializes in the serial production of concrete structures for offshore wind power foundations, including Hull, Spar, Semisubmersibles, and Gravity-Based Foundations (GBF). They offer expertise in designing and constructing floating foundations using innovative techniques like the slipform method. Additionally, they provide heavy-duty and gantry slipform systems combined with the IP-CCV Transfer System, offering contractors comprehensive solutions for foundation construction.

What distinguishes floating wind turbines from traditional fixed ones, and what advantages do they offer in terms of wind power effectiveness?

Floating wind turbines are constructed on floating platforms, allowing deployment in deep waters where fixed turbines are not feasible. They harness stronger and more consistent offshore winds, thereby increasing wind power effectiveness. Moreover, their mobility enables placement in remote areas far from urban centers, enhancing renewable energy accessibility.

Why are regions like India, China, and South-East Asia turning to floating wind power as an alternative to coal-based energy solutions?

These regions are embracing floating wind power to address the pressing need for large-scale renewable energy solutions as alternatives to coal. Floating wind turbines offer the potential to tap into abundant offshore wind resources, providing a sustainable energy source that can significantly reduce emissions and combat climate change.

What challenges do construction projects face when establishing wind turbines in areas with powerful winds far from urban centers, and how does floating wind power address these challenges?

Establishing wind turbines in remote areas with powerful winds presents logistical and infrastructure challenges. Floating wind power addresses these challenges by enabling the deployment of turbines further offshore, where winds are stronger and more consistent. This reduces the need for extensive onshore infrastructure while maximizing wind energy generation.

Partner up with us for your next project!

Our team of experts is ready to guide you through our innovative processes and show you how our solutions can meet your specific needs.

Don’t settle for less when it comes to your construction projects. Choose Bygging Uddemann, a world leader in the serial production of concrete structures. Let’s bring your vision to life with efficiency, consistency, and superior quality.