The offshore wind market is accelerating rapidly as global political pressure mounts to transition to clean energy sources. It is clear that floating offshore wind represents the next frontier, but which floating structure will deliver the best levelised cost of energy (LCOE)? Mark Goalen, Director of Offshore Engineering outlines some of the factors for consideration and explains how independent naval architecture consultancy can support informed decision-making.

Offshore floating wind is developing globally, particularly in Norway, UK, Europe, US, and Asia and is expected to grow from 70MW at the start of 2021 to 70GW by 2040. The long-term ambition is primarily to power the grid, however there are also ambitions to decarbonise offshore oil and gas installations and produce green hydrogen as a means to store or transport clean power.

Developers will not only need to consider the technology available, but also the local port infrastructure. Making the right decision to minimise costs and risks, requires in-depth analysis of a multitude of influencing factors; a serious undertaking in terms of research but one that has the potential to significantly pay off.

While the main challenge for the industry is now perceived to be a commercial one; how do you determine which floating foundation optimises the levelised cost of energy (LCOE)? Perhaps a more important question is, how do you establish the supply chain, and infrastructure required to deliver offshore floating wind on the scale required to meet the industry forecasts? There is no correct answer, it will vary from location to location.

There are four main types of floating wind foundations to consider (Spar, Semisubmersible, Barge, or Tension Leg Platforms), with multiple options for each type and still several more innovative concepts under development. Detailed motion response would need to be compared on a case-by-case basis for any specific location.  A foundation perfectly suited to the Mediterranean may not be well suited to the Pacific Ocean.

Decision making criteria including port infrastructure, supply chain, distance from shore, water depth, environmental conditions, motion response, risk, cost, and carbon emissions from the development for any given location would be evaluated.

Due to the complexities involved in assessing the most appropriate solution, it is essential to have the right expertise at the foundation selection phase to develop a holistic understanding of development thereby ensuring all aspects are considered to provide the best achievable cost advantage for the project. In-depth analysis conducted by independent naval architects that can remain entirely technology-agnostic will help determine which structure works best for any given location: a serious undertaking in terms of analysis and research but one that has the potential to pay dividends.