Offshore Wind Turbines: Concrete Foundations, Norway
A new and innovative design has been developed for concrete foundations suitable for large offshore wind turbines in water depths of 30-100m. This robust and durable solution significantly reduces risks and costs associated with offshore transport and installation, and has minimal impact on marine life.
The concrete foundation structure allows for inshore assembly of complete wind turbines including foundation, tower, generator and rotor. In this way the use of expensive offshore cranes for installation is avoided. The complete turbine is towed to site and installed by ballasting with seawater. The concrete foundation provides a stiff and strong base for the wind turbine preventing unfavorable dynamic effects and fatigue problems. Very long design life - 100 years or more – can be designed for. This opens the turbines up for reuse and adds significant value to the project since wind power will last indefinitely. The technology has been developed by Dr.techn.Olav Olsen, and is now owned and commercialized by the company Vici Ventus Technology AS.
Main Features
- Applicable water depths: 30 to 100 meters
- Simple and robust structure, long design life
- Can be towed to site complete with tower and turbine; heavy lift vessel not required
- Simple installation, by seawater ballasting
- Installation less sensitive to weather conditions than offshore lifting operations
- No piling - no disturbance of aquaculture
- Virtually maintenance-free foundation structure
- Suitable for all soils, from stiff clay/dense sand to soft soil
- Optimal stiffness and dynamic characteristics
- No fatigue issues for foundation structure, reduced fatigue of steel tower
- Simple to remove/decommission or reuse at suitable location
- Well-proven technology
- Patent pending