Cost of first US offshore wind installation vessel soars to more than US$700M

Dominion Energy said the CVOW Commercial project remains on schedule, as does construction of the vessel, but in a Q2 earnings call on 1 August 2024, the company confirmed that total project costs for the ship – including financing costs – had risen to US$715M compared with a previous update from the company of US$625M. The overall project cost, including construction and commissioning but excluding financing costs, was originally estimated to be around US$500M.

The company said the additional costs were a result of modifications to accommodate project-specific turbine loads based on final certified weights and dimensions of the equipment and additional financing costs. “Modifications will enable Charybdis to handle the latest technology turbine design,” said the company.

As of the earnings call, Dominion Energy said Charybdis was 89% complete, with an expected completion date of late 2024/early 2025 which, it said, “is supportive of schedule for the CVOW Commercial project.”

The company noted the vessel is “strategically important to Seatrium management,” and the shipbuilder had added senior and experienced project leadership from Singapore to Texas to support construction.

The vessel’s main crane structures and the helideck structure have been installed and work on upper leg construction continues on track. Seatrium has also commenced engine load testing.

At the time of writing, said Dominion Energy, the CVOW Commercial project is 33% complete, with 42 monopiles installed, with installation of scour protection for the first 23. The first cable is due to be laid later this year, followed by the first transition piece and offshore substation.

The first turbine is due to be installed towards the end of 2025, followed by the last monopile. The last turbine is due to be installed towards the end of 2026 and project COD. The CVOW Commercial project also remains on budget, the company confirmed.