Damen introduces fully electric offshore wind farm service vessel

The SOV 7017 E, developed by the Dutch shipbuilding company, is 70.1m (229.9ft) long and fitted with a 15MWhr battery, which the company says is sufficient to power the vessel during a full day of operations.

The battery is lithium iron phosphate (LFP), as opposed to the more conventional lithium nickel manganese cobalt (NMC) battery type. Damen says this maximises the vessel’s ‘sustainable credentials’, as LFP batteries offer the advantage of being less dependent on sensitive raw materials, particularly cobalt, as well as being less susceptible to ignition.

In the event that the vessel cannot access electricity for a short period, the SOV 7017 E features full redundancy and is able to continue operations with conventional diesel propulsion.

The propulsion system features four azimuth thrusters, which provide propulsion independently in any direction and offer considerably reduced underwater noise levels, according to the company.

Damen has partnered with UK-based MJR Power & Automation to develop the offshore charging system, as the company had previously developed a similar system for offshore charging for a crew transfer vessel.

The charging system uses the motion-compensated gangway to create a connection between the vessel and a turbine or substation offshore. The gangway is controlled from the wheelhouse, requiring no manual interaction with charging equipment.

Charging is carried out while the vessel is in a low power, so-called ‘green’ DP mode, which the developers say requires less energy than the hotel load. A full charge reportedly requires energy produced in just a few hours, by a single turbine.

MJR has developed a 4MW charger connector, sufficient for a 70-metre vessel, and the company says it is working on a scaled up 8MW version that will enable charging of larger vessels of up to 90 metres.

In a statement, Paul Cairns, MJR managing director, said: “The charging system is designed to be safe, convenient and reliable, with rapid connection and disconnection of the charge umbilical.

“Charging from an offshore asset represents optimal practicality, providing a means to reduce costs and emissions and optimise efficiency without placing personnel nor infrastructure in a potentially hazardous situation.”

The vessel is said to have storage space, workshops, and deck space to undertake the broad scope of transportation and work expected of it. Its 60 cabins provide accommodation for crew and up to 40 technicians.

Mark Couwenberg, Damen product manager, service operations vessels, said: “The product launch of the SOV 7017 E demonstrates that the technology is there to make offshore operations fully electric.

“To make this a reality will require collaboration throughout the chain, with shipbuilder, vessel operator and wind farm developer working together in pursuit of mutual benefit. We’re looking forward to participating in such cooperations as we take this concept forward. Together, we can make our offshore energy production more sustainable.”