Green, hydrogen-powered offshore turbine installation vessel from Ulstein

While wind is a clean energy source, the construction and service vessels used for offshore wind farms generally still run on fossil fuels.

To meet growing demand for zero-emission operations as well as the International Maritime Organization’s (IMO) target of halving maritime transport emissions by 2050, new vessels that run on alternative fuels are needed.

Hydrogen is one of the most promising alternative fuels for offshore vessels, and is completely zero-emission when produced with renewable energy or from natural gas with carbon capture. However, use of hydrogen as fuel currently faces several challenges, such as fuel storage and, in particular, a lack of bunkering infrastructure in ports. This is a classic chicken-and-egg dilemma.

The ULSTEIN J102 vessel uses a hybrid solution that combines a clean-burning hydrogen fuel cell system and a small battery energy storage system. This allows the WTIV to operate in zero-emission mode for 75 per cent of its operational time, which is when it is in a jacked-up position performing crane operations.

Ulstein has chosen to store the hydrogen on board in a flexible, containerised hydrogen gas storage system, making the vessel independent of hydrogen bunkering infrastructure. The hydrogen gas can be refilled by trucks at the quayside, or the storage containers can be lifted off the vessel and transported to an inland hydrogen plant for bunkering.

The current set up of the ULSTEIN J102 vessel already reduces CO₂ emissions by 4 000 metric tons and decreases emissions per installation cycle by 25 per cent compared with conventional power systems.

Using readily available technology, the system layout can be easily adapted as hydrogen technology and infrastructure evolve over time. The additional cost of less than 5 per cent of capital expenditures makes it affordable as well.

As a result, companies can begin the switch to zero-emission vessels today rather than waiting for hydrogen fuel technology to be perfected.

The offshore wind market is projected to reach USD 1 trillion by 2040 and is expected to drive demand for zero-emission vessels for offshore wind farms.

The ULSTEIN J102 design is market-ready and sea trials of a newbuild could take place as early as 2023.

Ulstein Group is a large group of shipbuilding, ship design and supporting companies. Founded in 1917, it is one of Norway’s largest shipbuilders and has been active in the offshore wind market for well over a decade.