Progress on First U.S.-Built WTIV as Costs Continue to Rise

Testing has begun on the first U.S.-built offshore wind turbine installation vessel, the Charybdis being built to operate for Dominion Energy. The company told investors last week that the expected delivery of the vessel, late this year or early in 2025, remains unchanged but the cost of the project continues to rise as further changes are made for its capabilities.

Dominion calls the vessel critical not only to its offshore wind plans but to the goals of the U.S. East Coast offshore wind industry. Ordered in 2020, the vessel is the first wind turbine installation vessel being built in the United States meaning it will be Jones Act compliant and have the most flexibility on its projects. Other WTIVs being built internationally will require feeder vessels to move material from the staging ports in the U.S. and face limitations as they are not Jones Act compliant.

The latest update says Charybdis is 89 complete, up from 82 percent earlier this year. Launched in April, the company said the hull was completed along with the commissioning of the four jack-up legs. Now they are reporting that installation of the main crane structures and the Helideck are completed and work on the upper leg construction continues on track. Main engine load testing has begun and main crane load testing is set to begin.

While the construction is making progress, the company reported it is updating the project’s current estimated costs, including financing, to $715 million. Earlier this year, the project was estimated at $625 million, after having started with an initial cost expected in the range of $500 to $550 million.

“The drivers for the increased costs are modifications to accommodate project-specific turbine loads based on final certified weights and dimensions of the equipment and additional financing costs. The modifications will enable Charybdis to handle the latest technology turbine design,” Dominion told investors during its August 1 presentation.

Work on the vessel began in late 2020 at the then Keppel AmFELS (now Seatrium AmFELS) shipyard in Brownsville, Texas, with the vessel expected to enter service by the end of 2023. At 472 feet in length, Charybdis will be one of the biggest vessels of her kind. Delivery will take place after the sea trials are completed. The vessel will then have additional work that will allow it to hold turbine towers, blades, and cells.

Currently, the vessel’s first deployment is set to begin in mid-2025 tied to the installation of the turbines for Dominion’s Coastal Virginia Offshore Wind. The wind project had previously set a 20-month charter for the vessel at an estimated cost of $240 million. 

Ørsted had chartered the vessel for work before Dominion’s CVOW, but that was later canceled when the Danish company retrenched its plans for U.S. offshore wind. Ørsted had cited vessel availability and supply chain issues among the challenges in the U.S. wind market.

Dominion also reported that work on the installation of the monopoles for CVOW is already one-third completed after having started in May 2024. Recently, a second vessel to generate the bubble curtain, a sound-dampening technique during installation, was deployed. The pace of installation is accelerating but will pause later this year before resuming in 2025. The schedule calls for all the monopoles and the first turbines to be installed by the end of 2025 and the projected completion by the end of 2026.

The company says interest in the vessel is strong from other projects. They expect to charter Charybdis for work after the completion of Dominion’s first offshore wind farm.