OSLO, Norway — DNV and various industrial partners have completed Phase 1 of a joint industry project (JIP) to optimize installations of offshore wind turbines.
Currently offshore wind turbine installation takes place largely in benign weather conditions to limit the bottom impact of turbine installation vessels’ jackup legs with the seabed during the set-down phase.
However, this restricts their operability and can lead to high day rates, with delays costly for operators and charterer. And regions exposed to earthquake risk also require operation of the crane with the vessel in a semi-jacked condition.
“As the industry moves farther into new territory with harsher weather, less forgiving seabed conditions and seismic areas, there is an increased urgency to widen the weather window,” said JIP steering committee chairman Andries Hofman of GustoMSC.
According to DNV, the lack of guidelines and models to fully understand bottom-impact forces and operations in the semi-jacked condition led to the formation of the JIP in November 2020. At that point, the goal was to investigate operational limits and potential new operational practices.
“The JIP work will be relevant for a long time to come, as bottom-fixed wind farms that require jackup installation will remain the most cost-attractive way to diversify our energy mix,” said JIP project manager Antonio Goncalves, business lead, Technical Advisory at DNV. “The market is developing quicker than the rules, and the only way to make significant leaps is through sharing knowledge. Through better understanding of the forces at play and their consequences, we can increase performance and safety in worse sea conditions, enabling more efficient and timely turbine installation.”
Under Phase 1, DNV developed a numerical model based on input from all the partners to accurately predict bottom-impact forces and simulate semi-jacked conditions.
More companies are now invited to join Phase 2, which will target validation of the developed models with full-scale measurements and establishing common best-practice guidelines. These can include energy companies, installation contractors, designers and shipyards, crane fabricators and wind turbine manufacturers.
The current partners are DEME Offshore, DNV, EDF Renouvelables, Fred. Olsen Windcarrier, GustoMSC, Huisman Equipment, Jan De Nul, Ocean Winds, Ørsted, RWE Renewables, Seajacks UK, Van Oord Offshore Wind, and Yantai CIMC Raffles Offshore.