Decommissioning of Offshore Wind Turbines: A model-based approach to assess cost reducing decommissioning methodologies

The first large offshore wind farms installed in the North Sea Region (NSR) soon reach their technical end of lifetime. The wind turbines in these farms will have to be decommissioned after power production has stopped. Currently offshore wind turbines are decommissioned based on a method called reversed installation, a time consuming and...

Feasibility assessment of motion compensated cranes at an early design stage

Current service and installation activities to offshore wind turbines (OWTs) are mainly carried out by jack-up vessels. These vessels are less susceptive to disturbances caused by sea waves when they lift their hull from the water level by jacking down multiple legs to the seabed. An alternative is a crane mounted on a floating vessel, which has...

Floating installation of offshore wind turbines in a single lift

The wind energy industry is booming. In 2017 the installed wind capacity has overtaken coal as the second largest form of power generation in Europe. Costs of wind farms are driven down, and even the first offshore wind-farm contract without subsidies is a fact. Installing the Wind Turbine Generators (WTGs) more efficiently increases the profit...

Enhanced Kalman filtering for a 2D CFD Navier-Stokes wind farm model

Wind turbines are often grouped together for financial reasons, but due to wake development this usually results in decreased turbine lifetimes and power capture, and thereby an increased levelized cost of energy (LCOE). Wind farm control aims to minimize this cost by operating turbines at their optimal control settings. Most state-of-the-art...

State-of-the-art design methods for wind turbine towers

The costs of wind energy have to be reduced in order to be competitive with conventional methods to generate electricity. The tower costs contribute significantly to the costs of a wind turbine. This thesis aimed to suggest improvements in wind turbine tower design in comparison with industry standards nowadays in order to reduce the costs of...

Predicting scale effects on floating offshore wind turbines

Floating wind turbines are becoming fashionable within the Renewable Energy world. In the last years MARIN has been involved in an increasing number of projects for the offshore wind industry. The complete simulation of a full-scale free-floating wind turbine under waves and winds using viscous-flow (Unsteady-Reynolds-Averaged-Navier-Stokes...