Offshore charging enables all-electric CTVs

Damen Shipyards Group has developed its concept for offshore CTV charging from a commissioning service operations vessel (CSOV) outfitted with a charger.

CTV owners will be able to install smaller battery modules on vessels, as power can be sourced offshore, said Damen sales manager for offshore wind Wijtze van der Leij. “Electric CTVs could charge from buoys, SOVs and turbines,” he said. “Integrating batteries, DC grids, drives and electric motors is important.”

MJR has supplied its offshore charging technology to Damen’s concept, which would enable the CTV to connect via a bell mouth that catches the charger, which is lowered from a reel on the aft deck of the CSOV.

After crew disembark, the CTV could connect using an automated process on a gangway. Charging will take 2-3 hours, depending on the operational profile.

"Such a solution makes it possible for CTV operators to invest today"

Vessel-to-vessel charging offers CTV owners and operators an opportunity to invest in the sustainable technology of the future, said Damen product manager for SOVs, Mark Couwenberg.

“Offshore charging is an essential feature for fully electric CTV operation,” he said. “Typically, this would be dependent on charging infrastructure being present at an offshore windfarm.” Which is why Damen and MJR developed this method of charging CTVs from CSOVs.

“This can be done with both a conventional, diesel-powered CSOV, or with a fully electric version. Such a solution makes it possible for CTV operators to invest today, in preparation for the wider distribution of full-electric CSOVs tomorrow.”

This concept uses Damen’s electric SOV 7017E design connected to a foundation on an offshore terminal, ready to connect to electric CTVs.

Damen has already developed charging stations for quayside applications, with the first installed in Vietnam and New Zealand, and an automated docking and charging unit for passenger ferries operating in Copenhagen, Denmark.

Chartwell Marine developed naval architecture for a 27-m CTV with batteries on deck for easy access for maintenance, charging and replacement.

“Charging at windfarms solves the conundrum of battery charging on CTVs,” said Chartwell senior naval architect Christophe Rident. “Owners can retrofit existing vessels or order newbuilds with electric propulsion.”

He thinks CTVs of 19 m length and larger could be fully electric or have battery modules and gensets to extend their range. Another design concept is lifting the CTV above the sea during transit on foils to raise hull efficiency and reduce resistance.

“There will be challenges with operating full-electric high-speed vessels due to costs and lack of charging infrastructure,” said Mr Rident.

North Star operates a Chartwell-designed 12-m monohull daughter craft with diesel and electric-powered outboard motors for offshore services with lower emissions.

Offshore charging MoUs

This Scottish owner has partnered with Stillstrom to develop and test offshore charging and vessel electrification technologies on an SOV in the North Sea.

If trials are successful, under the memorandum of understanding (MoU) both companies signed, Stillstrom charging units could be deployed on North Star’s growing SOV fleet.

Under another MoU, Maersk-backed Stillstrom and Port of Aberdeen will conduct a joint feasibility study into an offshore renewable charging hub.

In March 2024, Stillstrom signed an MoU with Port of Skagen to jointly explore the integration of offshore power and charging solutions into the anchorage zone of the Danish port, which is one of the busiest anchorage zones in northern Europe.

At the start of 2024, Stillstrom conducted a feasibility study for installing an offshore charging station on the Mona and Morgan offshore windfarms with support from developers EnBW and BP, evaluating the operational, technical and financial feasibility of incorporating offshore charging capabilities for SOVs and CTVs within the two windfarms.

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