The offshore floating wind market is expected to grow exponentially in the coming decade, but achieving a competitive Levelised Cost of Energy (LCOE) remains a major challenge.
A significant contributor to costs is the towing of Floating Offshore Wind Turbines (FOWTs) from manufacturing sites to wind parks and during maintenance operations requiring tow-back to port. Each tow-back represents a significant cost, including direct expenses and lost energy production.
Current towing practices are highly conservative, with low towing speeds (2–3 knots) and strict weather limitations (significant wave height often limited to 1–2.5 m). Combined with long distances and limited port infrastructure, these constraints lead to narrow operational windows and high costs.
Existing towing procedures are largely adapted from oil and gas operations, but FOWTs differ significantly in geometry, mass, and operational requirements. This creates new challenges such as:
- Uncertainty in predicting towing resistance and dynamic effects.
- Risks of flow-induced motions (FIM) like vortex-induced motions (VIM) and galloping.
- Complex coupled motions during towing.
- Limited weather windows and operability criteria.
To reduce costs and improve efficiency while maintaining safety, the industry needs better understanding of towing dynamics, validated numerical methods, and standardised guidelines.
The project is executed by a group of research institutes and universities, with support from classification societies and industry partners. SINTEF Ocean Acts as Project Manager, responsible for overall coordination, and integration of work packages.
Top image: Offshore, floating wind turbine. Photo: Vegar Johansen/SINTEF.