Damen Introduces Fully Electric SOV with Offshore Charging
Damen Shipyards Group has officially launched a fully electric service operations vessel (SOV), 70 meters x 17 meters, with its offshore charging capabilities.
To achieve offshore charging, Damen has partnered with UK-based MJR Power & Automation – a company that has previously developed an offshore charging system 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, in much the same way a personnel transfer is undertaken. Damen and MJR selected the charging method to maximize safety and efficiency. The gangway is controlled from the wheelhouse, requiring no manual interaction with charging equipment. It has the added benefit of utilizing pre-existing offshore infrastructure, thereby adding considerable cost-efficiency.
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 recognized safety standards, including IEC/IEEE 80005-1. Additionally, it is about to obtain DNV 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 the 70-metre vessel. The company is also working on a scaled up 8MW version that will enable charging of vessels up to 90 meters.
Paul Cairns MJR MD 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 optimize efficiency without placing personnel nor infrastructure in a potentially hazardous situation.”
Damen performed a business case analysis that took into account many different parameters, including investment cost for chargers and batteries, replacement of batteries, energy costs, price of CO 2, large variations of operational profiles, and charge times. The input parameters have been validated in close cooperation with wind farm developers and other stakeholders. Many different scenarios have been analyzed, but all ranged between five and 15 years.
The SOV 7017 E features a 15MWh battery, sufficient to power the vessel during a full day of operations. The battery is lithium iron phosphate (LFP) in place of the more conventional lithium nickel manganese cobalt (NMC) battery type. This is aimed at maximizing the vessel’s sustainable credentials. LFP batteries offer the advantage of being less dependent on sensitive raw materials, particularly cobalt. LFP also offers improved safety performance, being less susceptible to ignition and, in the event of ignition, being easier to contain.
If 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 SOV 7017 E boasts Damen’s DPX-DRIVE layout, featuring four azimuth thrusters providing propulsion independently in any direction and offering considerably reduced underwater noise levels.
The vessel has all the storage space, workshops, and deck space to undertake the broad scope of transportation and work expected of it. Its 60 cabins provide comfortable 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. 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.”
