A fresh breeze sweeps across the landscape. On the horizon, wind turbine blades turn steadily, generating renewable electricity. Yet even wind power has a sustainability challenge. Most rotor blades are made from glass fibre-reinforced composites, built up from layers of fibreglass fabric and carbon fibre bonded with resin in an energy-intensive manufacturing process. The blades are designed to last for decades, but not forever. Once retired, recycling them is often too complex and costly, leaving shredding and incineration as the most common options. As a result, the generation of clean electricity comes with a growing waste problem. Tom Siekmann has been thinking about a better alternative for years. His family has long been involved in the wind energy sector. “Even my father wondered whether rotor blades could be made from wood,” he says. For a long time, that vision remained just that. Today, advances in materials, manufacturing technology and engineering software have made it a realistic proposition. Convinced the time was right, Siekmann joined forces with Joachim Knapp and an experienced rotor blade designer to found Voodin Blade Technology in 2021.
Image: Voodin Blade Technology co-founders Tom Siekmann (left) and Joachim Knapp. Knapp is also Managing Director of Anker-Tec.
From concept to prototype.
Joachim Knapp is pursuing the venture alongside his role as Managing Director of Anker-Tec, a manufacturer of large CNC milling machines with extensive expertise in advanced production technologies. Voodin Blade’s team is spread across Europe, with Tom Siekmann based in central Germany, Joachim Knapp in the far north of the country, and engineering specialists working from locations across the continent. What connects them is a shared digital platform: 3DEXPERIENCE for data management, collaboration and process management, combined with SOLIDWORKS for engineering and design. The partners’ first proof of concept was straightforward: replace the existing rotor blades on one of Siekmann’s wind turbines with wooden ones. The original blade geometry was retained, with the material being the only fundamental change.
Image: The first 20-metre rotor blades are being produced at Anker-Tec’s demonstration centre. The next step: 40-metre blades and a dedicated manufacturing facility.
Knapp explains the process: “We digitally sliced the blade model into 50 mm cross-sections and milled each one from timber panels. Similar to 3D printing, we build up the blade layer by layer.” SOLIDWORKS provides the manufacturing data for the large gantry milling machine. The individual sections are assembled by hand to create an initial, still rough-edged blank. Once the adhesive has cured, the blade is machined again to achieve its final aerodynamic form. The finishing touches include lightning protection and the final coating. Knapp has extensive experience manufacturing large, complex components. “The work starts on the computer long before the first piece of timber is machined,” he says. The challenge is to consider design and manufacturing together from the outset. After all, even the most aerodynamically efficient blade geometry is of little use if no machine can produce it.
Image: Proof of concept, 2024: the first wooden rotor blades are installed on an existing wind turbine.
