Orsted is deploying three new hybrid crew transfer vessels (CTVs) from Northern Offshore Services (NOS) to assist with the construction of the 1400MW Hornsea 2 offshore wind farm, in the UK.
Sweden-based NOS has worked with MHO-Co to develop the vessels.
The CTVs will take around four hours to travel to site, from their base at the port of Grimsby, on the east coast of the UK.
The Hornsea 2 CTVs will also carry Z-Bridge’s newly developed motion compensated transfer system, called Bring-to-Work.
This transfer system will be installed as an additional feature for technicians to access the Hornsea 2 transition pieces directly from the CTV.
Orsted lead marine specialist Jan Stilling said: “The new CTVs have incorporated large battery capacity that makes it possible to stay offshore overnight in hybrid mode meaning they’re not burning fuel for up to eight hours while the vessels keep their positions without anchoring or mooring to a buoy.
“The new gangways will work as additional support for the extra access required during construction on site.”
NOS will take delivery of its 39-metre “Energizer” in spring 2021 and MHO-Co is due to deliver two 35-metre CTVs in the summer.
The batteries installed on all three vessels can be recharged either by power surplus, the onboard generator or via a recharging buoy system that will be tested during the construction face of the wind farm.
Both designs have been created in preparation for implementing fuel-cell technology once suitable storage for the fuel types such as hydrogen or methanol has been developed for use onboard.
NOS group CEO David Kristensson said: “I am grateful that NOS has been awarded the contract for supplying our CTV services to Orsted during the construction of Hornsea Two.
“Energizer, the first CTV in our E-Class series, represents years of research and development and will provide the best possible performance during the most difficult sea conditions.
“In addition, I am very excited about our new hybrid solutions that will reduce both the fuel consumption as well as the emissions at sea.
“The Hornsea 2 project represents the perfect start for our new vessel series.”
MHO-Co’s vessels feature both a diesel mechanical and a diesel electric Inboard Performance System (IPS) driveline setup in both hulls.
The diesel electrical drivelines can also be powered from the large onboard researchable battery pack during night-time and slow steaming.