The vessels will be built for Norwegian shipowner Olympic, which operates a fleet providing subsea and renewable services on the country’s north-west coast.
Serving as the integrator, Ulstein Power & Control will equip the vessels with the Corvus Orca Energy ESS.
Furthermore, the ships will feature hybrid battery propulsion based on the ULSTEIN SX222 design, as well as the TWIN X-STERN from Ulstein Design & Solutions.
According to Olympic Group, the TWIN X-STERN reduces energy usage as the offshore wind service vessels can mainly remain positioned by the turbines throughout operations.
The methanol-fuelled ships also have space for increased battery capacity, which will enable full-electric repowering.
The CSOVs are expected to be delivered next year.
Ulstein Power & Control official Rolf Ottar Rovde said: “Collaboration is key to finding the best solutions. The fact that they have a local office in Fosnavåg, close to both shipyard and owner, makes this a lot easier.”
Corvus Energy Sales vice-president Pål Ove Husøy added: “This is also a very important market for Corvus Energy as we see increased interest for batteries from the entire Offshore Wind segment, along with larger and larger battery installations.
“Due to the operational profile of SOVs, the potential for reducing emissions and costs by installing batteries is very high. This contract will be the largest battery installation for SOVs so far.
“This segment is also next in line for full zero-emission operations. With requirements for even larger battery systems, we see that our newly developed Corvus Blue Whale ESS has great potential for this vessel type.”
Last month, Ulstein Verft won a contract from Olympic Group for the construction of up to four CSOVs based on the Ulstein SX222 design with TWIN X-STERN.