The 2 MW wind turbine, which measures 150 metres to the tip of the highest blade, recently began supplying electricity to the Swedish grid, providing power for about 400 homes. Modvion invited BBC reporter Jonah Fisher to be the first journalist to view inside the wooden turbine tower – click here to see the video.

Wind turbines are more traditionally constructed from steel, which is strong and durable and has enabled huge turbines and wind farms to be constructed both onshore and offshore. However, as Modvion explained to the BBC, steel is not without its limitations, in particular for projects onshore. As demand has grown for ever taller turbines with greater power generation, the diameter of the cylindrical steel towers to support them has had to grow. Onshore, getting these to site, often through road tunnels, under bridges and around roundabouts, has become more difficult, limiting how tall new steel turbine towers can be.

In contrast to conventional steel towers, Modvion’s wooden turbine towers are modular in design, not only reducing the weight of a wind turbine tower by some 30% compared to steel, but making them more easily transportable. Once onsite, the curved sections are glued together in cylinders and stacked on top of one another, held by steel fittings and glued into place, to make the tower. As the wood is lighter than steel, taller turbines can be built with less material, notes the Swedish start-up company. The tower’s strength comes from the 144 layers of laminated veneer lumber (LVL) that make its thick walls.

This does not mean that wooden turbine towers will be taking over from steel in the future. Speaking to the BBC, Dr Maximilian Schnippering, Head of Sustainability at Siemens Gamesa – one of the world’s largest turbine manufacturers – noted that more pieces would likely mean more trucks, more people and more time to complete an installation. In his view, Modvion’s modular system was ‘an advantage’ and wooden towers would be ‘complementary’ to steel towers. He also noted that Siemens Gamesa’s efforts are focused on reducing the carbon footprint of the steel it uses in its wind turbines.

According to Modvion the life-cycle emissions from construction of a 110 metre tall wind turbine tower of steel is approximately 1,250 tonnes of CO₂, while the corresponding tower in wood emits 90% less emissions. Furthermore, ‘considering that the wooden tower also stores CO₂, the tower’s actual climate impact is lower’, claims the company.

In addition, Modvion reports that the life span of its wooden turbine towers is estimated to be 25–30 years, ‘exceeding the lifetime of the mechanical parts of the wind turbine’. Furthermore, on decommissioning, the company says the wooden towers ‘can be reused in conventional buildings and several other applications, for much longer than the regrowth cycle of Nordic forests, ensuring efficient bio-CO₂ capture from the atmosphere’.

Modvion is reportedly hoping to build another even taller turbine soon and is planning to open a facility in 2027 that will produce 100 wooden modular turbine towers a year.

‘The industry is currently putting up 20,000 turbines a year, Modvion CEO Otto Lundman told the BBC. ‘Our ambition is that in 10 years’ time 10% of those turbines – about 2,000 – will be wooden.’