SeaTwirl – combating climate change with floating vertical-axis wind turbines

SeaTwirl is an ambitious Swedish tech company working to become a global leader within floating offshore wind power.

As the global need for clean energy continues to grow, SeaTwirl is developing a floating vertical-axis wind turbine designed for offshore use from start. Strongly engaged in combating climate change, the company believes that their innovation can contribute to providing fossil free, renewable energy at a competitive price.

Business Development Manager at SeaTwirl, Efva Willén. Photo: SeaTwirl.
Business Development Manager Efva Willén.

- The awareness of climate change and how countries now realize they must take the necessary steps to eliminate the use of fossil fuels and find other – renewable – energy sources is a major trend that makes our solution possible. We can see this in how countries like USA, Japan as well as European countries now plan to invest big money in this conversion. The EU commission recently published their investment plan in offshore renewable energy, as one example, says Business Development Manager at SeaTwirl Efva Willén.

SeaTwirl’s wind turbines are easier to build, install and require less maintenance than traditional solutions based on horizontal-axis wind turbines, according to the company. SeaTwirl’s technology use a vertical-axis wind turbine with a tower connected to the floater, consisting of a spar buoy with a heavy keel plate. As the energy of the wind causes the turbine to rotate, the structure maintains its stability by using the keel and the counter turning moment, like the function of a keel on a sailboat.

- During a fishing trip in the summer of 2006, inventor Daniel Ehrnberg, was inspired by the twirling motion of the water around the oars and began to think about how a floating wind turbine could be vertical and connected to a rotating floater. Ehrnberg had experience working with wave power and an interest for renewable energy and now he wanted to find out how the ocean winds could be used as a source for renewable energy. In a matter of years different tests with smaller prototypes were performed and late 2012 SeaTwirl was founded, Willén says.

- In 2015, SeaTwirl’s prototype S1, a 30kW wind turbine, was installed in the sea off Lysekil – Sweden's first floating wind turbine! Based on the experience from SeaTwirl S1, the development of SeaTwirl S2, a wind turbine with 1 MW installed turbine power, was started, Willén continues.


SeaTwirl logo


Today SeaTwirl is constantly growing, counting 13 full time employees, as well as numerous sub-contractors for specific work packages. SeaTwirl are also building a world class competence centre for floating offshore wind in their hometown Gothenburg. When asked about the reasons for the company’s success so far, Willén is clear:

- It is the right time for working with renewable energy. It is one of the most important subjects in the public debate, the media writes about combating climate change every day and we experience much general interest in our company. Climate change is one of the biggest challenges of our time, where a crucial step is to make the world's energy production fossil-free, not least renewable. The offshore wind industry is one of the world's fastest growing sectors and SeaTwirl is a part of that industry.

- A comprehensive market survey has shown that islands and coastal regions as well as fish farms needing renewable energy could be suitable applications for SeaTwirl S2 in the local grid market.We would contribute to switching from diesel electric to renewable power. We are also looking into the utility grid market, where we will supply renewable energy to the utility grid from future larger SeaTwirl turbines in offshore wind farms, Willén adds.

The growing awareness of the importance of combating climate change has permitted SeaTwirl to enter the emerging market of floating offshore wind. According to The EU Offshore Renewable Energy Strategy, the European Union is reassuring its commitment to offshore renewable energy by encouraging estimated investments of whopping €800 billion between now and 2050. SeaTwirl aims to commercialize their large S2-model soon after the launch of the pilot in 2022, as well as developing a larger model, currently named SX. SeaTwirl has a clear vision to become a global leader within floating offshore wind power, and has already received €2,48 million from the European Innovation Council’s SME instrument as well as €500,000 within the OESA Interreg project (Ocean Energy Scale-up Alliance).

Wish to know more about SeaTwirl? Read here or get in touch at

Periscope aims at establishing a permanent innovation ecosystem in the North Sea Region to grow transnational innovation partnerships for sustainable business development in emerging blue markets. Wish to know more about Periscope? Read here or get in touch at

Images © SeaTwirl

By Theodor Barndo…