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Wind turbine towers made of natural carbon fiber

Published 2022-08-10

Wind turbine towers made of natural carbon fiber

Gothenburg-based Modvion is challenging the wind power industry with a patented concept for modular towers made of laminated, curved plywood from Nordic spruce. Nordtec has provided Celsicom products in the development phase. Wood Technology Company CEO Otto Lundman talks about the benefits of all-wood wind towers, why height matters and what the vision is.

Founded in 2016, Modvion develops modular, climate-smart solutions. Last spring, the company erected its first, 30-meter-high wooden tower on the island of Björkö in Gothenburg’s northern archipelago. They are now working hard to produce the first commercial tower, which will be three times as high.

How was the idea of wooden wind turbine towers born?
– My co-founder David Olivegren, who has a background in architecture and boat building, had long been fascinated by the strength of curved wood. When David saw a 100 meter high wooden tower in Germany about ten years ago, he immediately saw the development potential and thought: “That can be done better”. This is exactly what drives us at Modvion, trying to make smart wooden towers,” says Otto Lundman.

Which metrics are important for you to keep track of?
– In our quest to build climate-smart wooden towers, we conduct tests and proof of concepts (prototypes). As a first proof of concept, we built and erected the 30 meter high tower on Björkö. We needed to keep a close eye on and monitor everything that happens in the tower. Such as continuous logging of humidity and temperature to validate that the wood is behaving as it should according to our calculations. Above all, it is important for the material to retain its strength properties.

– Of course, steel wind turbine towers must not rust. When it comes to our wooden structures, it is important that they stay within certain moisture levels. It is not good if the moisture values vary too much. This can be seen on a bridge that is sometimes washed over, sometimes dried up.

– Therefore, we treated the tower on Björkö with a special coating. That is, a protective paint that allows us to have a controllable air volume inside the tower. To keep track of the moisture levels within certain ranges, we use Celsicom loggers from Nordtec.

What are the main advantages of wooden thorns?
– They enable the high and more cost-effective wind power installations everyone wants. Thanks to the modular solution and low weight, all transportation issues are eliminated. Our towers are also made of a material with very high specific strength.

– Laminated wood is extremely strong by weight. We achieve the same strength as a steel tower but with two thirds of the weight. In addition, wood is a material that does not emit much carbon dioxide during production, but is instead a ‘carbon store’. During its growth, the tree has absorbed carbon dioxide from the atmosphere and stored it as carbon in itself.

– Steel or concrete tower structures emit a lot of carbon dioxide during their construction. Sure, these materials are great in the right context. But we must not be complacent about using materials that together account for almost 20% of the world’s carbon emissions.

Why are taller towers more cost-effective?
– It’s all about the wind gradient (profile of how wind changes at different heights). Closer to the ground, hills and vegetation disturb the wind, creating a turbulent flow, while at higher altitudes you get a laminar flow with stronger and more stable winds. And the higher you go, the bigger the rotor you can use. In turn, a larger sweep radius means you can use a larger generator and achieve economies of scale.

Otto Lundman, Modvion

We have high ambitions!

Otto Lundman

Co-founder and CEO

What reactions have you had to the wooden thorns?
– Initially, when new technologies are introduced, there is often some skepticism. But it is about showing what you have, which we have done. Not least with the tower on Björkö. It made a big impression.

– We have now established a number of partnerships with major players in the industry. Earlier this year, for example, industry giant Vestas stepped in and became a small shareholder in Modvion. Our common ambition is to bring the towers to the market on a wide scale and help reduce the climate footprint of wind power even more.

– There is an effort to make our societies climate-neutral, and of course wind power wants to be at the forefront. And our towers make it possible to reduce the already low carbon footprint per kWh by as much as 30%.

What are you mainly working on now?
– We are now very busy working out all the details of the first commercial-scale tower that we are erecting next year for Varberg Energi. The total height will be around 150 meters, of which the tower is 100 meters.

Factory picture Modvion
To keep track of moisture levels within certain ranges, Modvion uses Celsicom loggers from Nordtec.

– In parallel with the completion of this tower, we continue to refine the technology in our Gothenburg factory and plan for larger volume production. We are looking for a factory that can give us an initial capacity of around 200 towers per year. Where the first volume factory will be located remains to be seen. Talks are ongoing with several partners.

What are the prospects for the future?
– We have high ambitions. Modvion wants to influence our power generation and help reduce our carbon footprint. The individual tower is interesting from an engineering perspective, but to make real climate benefits, large-scale production is required. Around 22,000 wind turbine towers are erected around the world every year and it is a growing market. We aim to produce thousands of towers per year by the end of the decade, reaching a percentage of the world’s supply and making a real difference.

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Contact persons

Thomas Ottosson

CUSTOMER SERVICE AND SALES

Thomas Ottosson

Area of responsibility: Industrial and stationary
applications

thomas.ottosson@nordtec.se
031-704 10 87
031-704 10 70