From feasibility to technical possibility and now official launch, a fully electric Service Operations Vessel (SOV) is set to pave the way for significantly reduced emissions in the maintenance of offshore wind farms.
Damen Shipyards Group has partnered with UK-based MJR Power & Automation to achieve offshore charging on the new SOV 7017 E, using a motion-compensated gangway to create a connection between the vessel and a turbine or substation offshore, in much the same way as a personnel transfer is undertaken. The gangway is controlled from the wheelhouse, requiring no manual interaction with charging equipment. It has the added benefit of utilising pre-existing offshore infrastructure, adding considerable cost-efficiency.
MJR’s MD Paul Cairns states, “The charging system is designed to be safe, convenient and reliable, with rapid connection and disconnection of the charge umbilical. From the outset of this project, the priority has been to ensure the safety of personnel and integrity of the vessel and offshore assets, under all conditions. Charging from an offshore asset represents optimal practicality, providing a means to reduce costs and emissions and optimise efficiency without placing personnel or infrastructure in a potentially hazardous situation.”
The SOV 7017 E features a 15MWhr battery, sufficient to power the vessel during a full day of operations. The battery is lithium iron phosphate (LFP), aimed at maximising the vessel’s sustainable credentials, being less dependent on sensitive raw materials such as cobalt. LFP also offers improved safety performance, being less susceptible to ignition and, in the event of ignition, being easier to contain.
Charging is carried out while the vessel is in a low power, so-called ‘green’ DP mode, requiring less energy than the hotel load. A full charge typically requires energy produced in just a few hours by a single turbine.
The system is designed according to international recognised safety standards, including IEC/IEEE 80005-1. Additionally, it is about to obtain DNV AIP (Approval In Principle) and is designed in accordance with forthcoming offshore charging standards under collaborative development by DNV UK and Norway.
MJR has developed a 4MW charger connector, sufficient for a 70-metre vessel. The company is also working on a scaled up 8MW, version that will enable charging of larger vessels, up to 90 metres.
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. The reduction in OPEX implied by harvesting energy directly from the offshore wind farm implies a business case for this model.
“We cannot do this alone, however. 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.”
