Introducing composite towers in the offshore wind industry will benefit the profitability of offshore wind by reducing installation costs (less weight), reducing maintenance costs by using less corroding materials and improving operational lifetime using the positive damping effects of composite materials. An opportunity for The Netherlands to develop its component-production industry and make the feasibility of floating wind turbines worldwide more realistic.

Together with two project partners, Jules Dock and WMC, TNO develops a composite tower using an integral design approach including optimizing the power control algorithm and LCOE evaluation compares to the steel tower.

First, TNO specifically develops new controllers for both onshore and offshore turbines taking into account the much lower eigenfrequencies and tune the control parameters in during the design iterations for use in design with the flexible lightweight tower. The offshore turbine in this project is based on 10 MW WT. On the other hand, the onshore WT is based on a commercial multi-MW wind turbine design.

C-Tower scale model in test setup at TNO Delft

Next, TNO performs a cost analysis to determine the integral effect of the application of a lightweight composite tower on the Levelised Cost of Energy. The focus of the analysis will be on the replacement of the conventional steel tower with a composite tower. The calculation main focuses are installation, O&M, and components costs and characteristics difference between composite and steel tower. TNO will use its ECN Cost Model for this task, a tool based on engineering relations or simplified design models. Especially the tower, support structure and rotor blades cost is based on engineering relations. The Installation and O&M cost effects are determined using approximations of ECN Install and ECN Cost Calculator.

Lastly, TNO performs a Life Cycle Assessment (LCA) analysis to determine the (integral) effect on environmental performance parameters commonly used in LCA analysis. For the LCA analysis, the different production processes of the tower will be taken into account. This task also produce end-of-life strategy scenarios composite towers


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Novita Saraswati

  • Wind Energy Technology
  • Offshore Wind Farm Installation
  • Offshore Wind Farm Operations and Maintenance