Design and validation of modular wind turbine towers made from wood

As wind turbine towers grows taller and wider, transportation issues of large parts to the site have appeared due to restriction on the roads. The company Modvion develops a modular design of wind turbine towers made of wood products and their concept provides advantages concerning transportation and assembly. The concept makes it possible to build taller towers at lower costs, reduced CO2 emission and excellent dynamic properties. Detail analyses and aero elastic simulations of a 150 meters tower equipped with a 126 meters generic wind turbine has been executed with promising results. By increasing the tower height with 20 - 25 %, similar dynamic properties and Campbell diagrams are achieved as conventional state of the art steel towers. The joints between the wood part sections are design drivers. Therefore, these have been analysed carefully for a enough structural integrity, simple implementation and low cost. Specimens of the joints have been manufactured and tested at RISE workshop to validate the strength. They have been pulled to fracture from both ultimate and fatigue loading. The repeatability is good and in line with standards and requirements. A 30 meters demonstration tower for the upscaled Chalmers university 45 kW research wind turbine is now in manufacturing, to be erected and commissioned later in this year