Stillstrom completes tests of unit to charge wind farm ships at sea

Maersk’s offshore vessel-charging venture Stillstrom has finished building and factory-testing a containerised unit that links a service operation vessel (SOV) to a turbine’s high-voltage cable, so the ship can charge its batteries at the wind farm.

IMAGE: Stillstrom’s containerised unit for charging vessels. Stillstrom

SOVs act as floating bases for technicians at offshore wind farms. Classification society DNV witnessed the tests, and Stillstrom describes the unit as the world’s first of its kind.

The unit can be installed on newbuilds or retrofitted to existing ships, and moved between vessels where onboard cabling allows.

The full system, including the wind farm interface, would be “ready to go to work at sea” by the middle of next year, Stillstrom UK managing director Graeme Wood said. The company expects extended offshore trials by next summer, and a second design will move the semi-automatic alignment towards full automation. The release does not say which wind farm or vessel operator will host the trials.

Stillstrom partnered with offshore vessel operator North Star in August 2023 to recharge the operator’s hybrid-electric SOVs from wind power in the field. Its first vessel trial followed in November 2024, when the offshore supply ship Maersk Lifter plugged into a quayside unit at the Port of Aberdeen for three charging cycles.

A consortium led by Stillstrom also won €5 million ($6 million) of EU funding in May for a 36-month pilot of an offshore power zone at Skagen in Denmark, where anchored vessels keep their engines running.

By Tuhin Roy

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