Offshore wind: installation vessels and time per turbine?

Wind turbine installation vessels are estimated to cost $100-500/kW in the breakdown of a typical offshore wind project’s capex. Total offshore construction time is around 10 days per turbine. Offshore wind installation vessel time per turbine averages around 5 days per turbine. Data from past projects are tabulated in this data-file.

The average offshore wind project comprises 90 turbines. Hence over the entire course of offshore construction, a full turbine is installed every 10-days on average.

However, over 50% of the time is spent on preparations, foundations, cable-laying and commissioning. The average wind turbine installation vessel installs a full turbine every 5-days.

The numbers vary by project. The best installation vessels operating under the best conditions can install an entire turbine upon pre-laid bases/foundations in a single day.

At the other end of the spectrum, installation can take over ten days per turbine, especially amidst bad weather, delays with parts, mechanical issues, and projects that are a long way from ports.

Offshore wind installation vessel time per turbine? Data on the times taken to install an offshore wind turbine are aggregated across 35 offshore wind projects in this data-file. While the data are interesting, there are few correlations to be drawn between simple headline metrics.

Some eagle-eyed readers will have spotted, in the charts above, that some projects appear to have higher WTIV days per turbine than total construction days per turbine, which seems confusing. The reason is that recent large offshore wind projects will tend to have 2-3 installation vessels operating simultaneously. Thus they can achieve 2-3 WTIV-days of work per calendar day. More vessels will mean faster construction. And probably lower total costs. But it will also require booking out more vessels from the total fleet.

Overall, we think that installation vessels and support vessels could be a bottleneck for accelerating offshore wind. Amazingly, some of the largest projects in the history of the industry had 60 – 100 vessels operating at peak construction activity.

For perspective, recent offshore wind projects likely have total installation costs of $2,000-6,000/kW (offshore wind cost data here, breakdown of turbine cost here). Cost is saved by larger turbines. The other large bottleneck is in downstream power electronics for integrating wind with power grids.

Leading companies in offshore wind turbine installation vessels include DEME, MPI, Van Oord, Cadeler, Eneti (Seajacks), and increasingly, private-equity backed vessels gearing up for an expansion of offshore wind, especially in the US.

Copyright: Thunder Said Energy, 2019-2023.