Stillstrom Builds Vessel-Mounted System for Direct Offshore Wind Charging

(Credit: Stillstrom by Maersk)

Stillstrom by Maersk has completed the construction and factory acceptance testing of what it describes as the world's first 11 kV vessel-mounted connection unit designed to charge service operation vessels (SOVs) directly from offshore wind farms.

The milestone, witnessed by DNV, marks the completion of testing for Stillstrom's Vessel Container Unit (VCU), a modular system designed to transfer electricity from offshore wind infrastructure to vessel batteries.

The containerised unit houses an 11 kV connector package and can be installed at the bow, stern or beneath the deck of a vessel, allowing integration into both newbuilds and existing vessels.

The unit can also be transferred between vessels where onboard cabling permits, while its integrated funnel enables charging at an optimal vessel heading, with the dynamic positioning operator retaining control over charging and disconnection.

The system incorporates control technology and safety interlocks designed to support repeated offshore connections and disconnections.

“High-voltage power has never been transferred to a vessel offshore in this way, and the connector package inside our VCU represents several years of careful development and testing,” said Graeme Wood, Stillstrom UK Managing Director.

(Credit: Stillstrom by Maersk)

Work on the wind farm topsides interface is continuing, with the complete charging system expected to be ready for extended offshore trials by summer 2027.

Stillstrom is also developing a second-generation version of the VCU, known as Mark 2, which aims to move from the current semi-automatic alignment system towards full automation.

The company’s offshore charging technology is designed to supply renewable electricity to fully electric and hybrid service operation vessels, using systems integrated into offshore wind farm structures or standalone offshore installations.