Stillstrom Picks Semco for Offshore Charging Equipment

(Credit: Stillstrom by Maersk)

Stillstrom by Maersk has signed a letter of intent (LOI) with Semco Maritime to manufacture and deliver a key part of its offshore vessel charging system, moving the technology into manufacturing following completion of its design phase.

Semco Maritime will manufacture the local equipment room, or local equipment room (LER), which controls power, communications and safety functions across Stillstrom's offshore charging infrastructure.

The containerized unit houses the transformer and medium-voltage switchgear used to transfer offshore-generated electricity from a wind farm to a vessel, alongside communications equipment, ventilation and fire safety systems. It is designed to be installed on a monopile or hang-off structure at each charging location.

Manufacturing is planned at Semco Maritime's facility in Esbjerg, Denmark, with completion targeted for spring 2027. Stillstrom said future units could potentially also be manufactured at Semco Maritime's UK facilities.

“Completing the design and now moving into manufacture is a major milestone for us. The LER is extremely significant to our solutions as it acts as the nerve centre of our charging system. It controls everything that happens, from how power reaches the vessel to how every safety system talks to each other. Without it, nothing in the system moves,” said Gordon Dickson, Stillstrom UK operations and maintenance lead.

The LOI, signed at WindEnergy Hamburg on September 23, follows completion of the LER design phase by Semco Maritime earlier in 2026.

Siemens will supply the switchgear and control systems as a subcontractor. Semco Maritime and Siemens signed a separate LOI covering that scope at WindEnergy Hamburg.

Semco Maritime also supported a recent Stillstrom yard trial that demonstrated fully automated cable control while a vessel operates on dynamic positioning.

Stillstrom's technology is designed to provide offshore power and charging for fully electric and hybrid service operation vessels, either through equipment integrated into offshore wind structures or standalone installations.