Coastal Virginia Offshore Wind: three key elements of the supply chain story

The 2.6 GW Coastal Virginia Offshore Wind (CVOW) project is the largest such project in the United States. It features 176 monopile foundations and three offshore substations with construction expected to be completed in late 2026. 

One of the most notable aspects of the CVOW construction scope is that it marks the maiden turbine installation campaign for Dominion Energy’s own Charybdis. This is the first Jones-Act compliant wind turbine installation vessel (WTIV) built in the U.S. and represents a critical step in building domestic offshore wind installation capacity. 

The scale of the CVOW development demands a massive and highly coordinated supply chain, much of which is reliant on European manufacturing and transatlantic logistics. Here, Spinergie’s senior offshore wind analyst Maëlig Gaborieau shares three supply chain elements that demonstrate the magnitude of this landmark project. 

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A predominantly European supply chain

A lack of manufacturing facilities in the U.S. means developers must look elsewhere for their wind farm components. This is why CVOW, with no Tier 1 components manufactured locally, has a supply chain that heavily relies on transatlantic logistics. 

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Nearly all of CVOW’s Tier 1 components (towers, nacelles, blades etc.,) were produced in Europe across 11 factories. There was little representation from the Americas in terms of manufacturing, however, a significant number of towers were produced in Mexico. 

Monopiles, nacelles and array cables were produced in Germany; Topsides, TPs, blades and OSS jackets were produced in Denmark while additional components were manufactured in Finland (export cables), the UK (blades), Portugal (towers), Italy (export cables) and Greece (array cables). 

All of these components were transported by sea to the Portsmouth Marine Terminal in Virginia—the marshalling port for CVOW. For the European voyages, on average, Heavy Load Carriers (HLCs) and barges have to cover more than 6,000 km per delivery which corresponds to a 14-day journey for each trip. 

This highlights the current dependence of U.S. offshore wind development on foreign manufacturing and long-distance logistics.

‍Five countries were involved in Siemens turbine production 

With 176 turbines to install, CVOW represents a major industrial endeavor for turbine manufacturer Siemens Gamesa and its global manufacturing network. 

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The nacelles alone, produced in Germany, account for over 70% of the facility’s estimated annual output, effectively securing a significant share of its production capacity for the year.

Blade production is even more striking: the project requires 528 blades, which equates to over 80% of Aalborg’s estimated yearly capacity and nearly 90% of Hull’s, suggesting both factories were heavily mobilized. 

On the tower side, Altamira in Mexico and Aveiro in Portugal contributed 90 and 86 towers respectively, accounting for a substantial portion of each plant’s capacity. 

Securing a project of this scale provides long-term visibility for manufacturers and ensures full, or near full, utilization of key Siemens facilities across multiple countries.

‍Ever-increasing transport vessel days

The number of transport vessel days recorded for CVOW have been steadily climbing since September 2023. Activity peaked in spring 2024 with the start of monopile installation, then surged again in late 2024 with the shipment of substations and continued foundation components. 

A new uptick is expected in the coming months, as the long-awaited Charybdis WTIV has now begun its maiden charter. Now, the volume of turbine component deliveries (blades, nacelles, and towers) will go into full swing, likely pushing monthly vessel days to new highs.

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This analysis was compiled using Spinergie’s supply chain module. The module offers real-time insights into global offshore wind supply chains featuring detailed component specifications, manufacturing schedules, and updates on contracts and logistics. Users can assess manufacturing capacities, compare different projects and components, and spot market trends with built-in tools such as lead time analysis. By integrating data on transportation and marshaling performance, this module empowers developers, manufacturers, and vessel operators to optimize projects. Find out more in our white paper or book a demo.