Offshore charging field trial to commence in 2025

Offshore charging will also be available to provide power to service operation vessels (SOVs) working in windfarms once these concepts are proven. SOVs are now being built with battery hybrid propulsion and engines ready to run on alternative fuels to diesel.

GC Rieber Shipping is awaiting delivery of the first of two Windkeeper SOVs from Cemre shipyard in Turkey in Q3 2025.

Both vessels are being built with a small waterplane area twin-hull (SWATH) design and are prepared for offshore charging, said GC Rieber chief technical officer Gjert Florvog.

He said these Windkeeper SOVs are equipped with DC grids and propulsion technologies to reduce fuel consumption and be ready for future conversion to an alternative fuel.

“Electric is the easiest way to get the power, but we need infrastructure to be available, and a viable and strong business,” said Mr Florvog.

“There is a super-grid out there, but it is difficult to get connections for SOVs. New windfarm projects need to look at opportunities for offshore charging. It is important to establish infrastructure to build and develop now, to get away from marine gasoil.”

Damen Shipyards has developed battery-hybrid SOV designs and partnered with MJR to test offshore charging. Its SOV 7017 vessel will have 15 MWh of batteries, while its commissioning vessel of CSOV 9020 design would include 25 MWh of energy storage.

Its SOV design includes a 3D motion-compensated gangway to grab the cable from the charger, then pull it to the vessel for the power connection, said Damen design and proposal engineer Rebecca Belmer.

“This would be all automated and if the vessel drifts off the turbine, then the vessel can emergency release the cable and sail away,” she said.

It is envisioned an SOV would drop off technicians and use its idle time to charge, so it is ready to pick them up again. “How this would work in a 24-hour day would depend on the number of charge points, drop off tasks, time waiting for work, the installed battery capacity, power demand on the vessel and the operating profile,” said Ms Belmer.

The Maritime Hybrid, Electric & Hydrogen Fuel Cell Conference took place in Bergen, Norway, on 29-31 October 2024, looking at key trends, regulations, class rules and the development of zero-emissions ecosystems. 

Riviera’s Maritime Decarbonisation Conference, Americas will be held in Houston, Texas, 4 December 2024. Click here for program information, tickets, or to register your interest in this industry-leading event.