Heavy-duty solutions for wind farm operations and maintenance

With offshore wind maturing rapidly, so are the Operations & Maintenance (O&M) requirements to keep offshore wind farms operating efficiently. While O&M is common in the industry, the rapid expansion and maturity of installed wind farms in recent years have increased the need for heavy O&M and main component exchange or replacement. Consequently, the demand for vessels supporting these activities is increasing and is expected to continue growing.

To meet this demand safely and efficiently, GustoMSC has been developing specific solutions for these activities. There are jack-ups and vessels dedicated to heavy O&M operating at the moment; however, most heavy O&M has been carried out by “jack-ups and vessels of opportunity” in the past, both in main component replacement and activities such as cable repair. With high demand for both the construction of wind farms and increasing demand on the O&M side, this is expected to become more challenging.

Additionally, the capacity requirements for these activities are increasing. With increasing turbine capacities, the weights and required lifting heights for main component replacement are also increasing. Cable failure is a recognized challenge for the industry and needs robust and timely solutions. Furthermore, deeper waters and more remote locations impose their unique requirements.

GustoMSC has developed solutions to meet these expanding challenges based on its proven range of self-propelled jack-up designs and its expanding range of vessel-based solutions.

Jack-ups for main component replacement
With increasing lifting heights and tight tolerances for main component replacement, jack-ups are the primary tools in an O&M strategy for this work. Dedicated self-propelled heavy-lift jack-up designs can be more efficient to operate in this market than the large Wind Turbine Installation Vessels (WTIVs) which have been employed as vessels of opportunity. They can be designed more compactly, and therefore more affordable and less expensive to operate.

For the current range of turbines operating or being installed, GustoMSC jack-up designs like the NG-3750C, as recently built for Penta Ocean, and the NG-5500X, of which one unit was built as the Apollo for DEME, are used as the basis for O&M-specific jack-ups. For the next generation of turbines, the capable NG-8000X design has all required capabilities. These designs offer stable and highly efficient crane platforms able to work in the challenging conditions and increasing water depths where today’s wind farms are installed and planned.

These jack-up designs benefit from GustoMSC’s telescopic leg cranes and digital solutions. Combining a compact jack-up platform with cranes of increased lifting height and capacity, the telescopic leg crane offers maximum utilization of deck space and improved seakeeping and maneuvering characteristics in the wind farm, as well as easier boom storage between lift operations. This is complemented by digital solutions that enhance jacking operations and allow safe and efficient lifting operations.

Beyond the CSOV
A wide range and quickly expanding fleet of Service Operations Vessels (SOVs) and Construction Service Operations Vessels (CSOVs) are serving the O&M market to meet its demand for regular maintenance and maintenance support by providing walk-to-work services and the ability to transfer smaller items to and from a turbine.

Heavier maintenance, specifically including balance-of-plant scope such as cable repair and activities involving heavier lifts, are outside the capabilities of these vessels. To meet this demand, GustoMSC has launched its MSOV concept, based on its Enhydra vessel design series.

The MSOV is designed to be quickly mobilized for cable repairs. It offers heavier, motion-compensated lifting capabilities in the wind farm that also allow for secondary steel repairs and incorporates the capability to perform subsea inspections. This capability is offered while maintaining the typical SOV capabilities such as walk-to-work, high-end accommodation, and incorporated daughter craft, combined with excellent seakeeping and Dynamic Positioning (DP) capability.

Looking forward, the capabilities of the MSOV design also make it particularly suitable for O&M operations in offshore wind. With all the challenges associated with offshore O&M operations further amplified for offshore wind, the larger and capable design makes it a perfect fit for all O&M operations, from walk-to-work to executing tow-in tow-out operations, including re-mooring and hooking up to the dynamic cable of the floater when arriving back in the wind farm.

In addition to their core capabilities, these new designs, both jack-up and vessel-based, offer further advantages compared to vessels of opportunity. Lower operating costs resulting from a fit-for-purpose design, but notably also a lower environmental footprint as the latest in battery-hybrid operations and future fuels have been incorporated into the designs.

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