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Harnessing the Power of Floating Offshore Wind
Harnessing the Power of Floating Offshore Wind
by Sigurd Solheim Pettersen, Bente Pretlove, and Kristin Nergaard Berg
The US offshore wind sector has entered 2024 with cautious optimism as the industry shakes off negativity from last year, ready to apply learnings from a challenging 2023 to the year ahead. There are already key projects in the pipeline, including the Revolution wind project expected to start construction in the spring, and the commercial CVOW project expected to start construction in May.
Joining the United States, Canada has recently announced their plans to develop wind off the coasts of Newfoundland and Labrador. With several offshore wind areas in waters too deep for fixed-bottom technology, floating wind has emerged as the technology developers are evaluating for their projects. Floating wind allows access to the US West Coast for offshore wind development and greater wind resources farther off the East Coast.
A recent report forecasts that, by 2050, 17 percent of all accumulated offshore wind installed capacity globally will be floating offshore wind. This means that approximately 270 GW of floating offshore wind will be installed in the next 30 years. This will require around 18,000 turbines, each mounted on top of floating units weighing more than 5,000 tons, and secured with so many mooring lines that if they were tied end-to-end, they would more than wrap around the world.
While the sector presents significant opportunities, it also comes with a range of new challenges as developers consider projects further offshore in deeper waters. This growing market is still in its relative infancy; for floating offshore wind to achieve its full potential, it must overcome a number of challenges, including technical, commercial, and societal.
Driving standardization to support reduced LCOE
As a relatively new technology with few operational turbines, the levelized cost of energy (LCOE) for floating offshore wind remains very high. For this technology to scale faster, it is paramount that the LCOE be reduced as much and as quickly as possible. The global average LCOE for floating offshore wind is predicted to fall 75 percent by 2050. This drop will depend on factors like cumulative installed capacity, economies of scale, and serial manufacturing, with reductions in the cost of floating structures and turbines being the main contributors. LCOE will vary significantly between global regions. Wind farm size increase will be a key driver of LCOE reduction, as moving from pilot to commercial sized wind farms allows for scaling effects and standardization, which again will become a key enabler for industrialization, further driving cost reduction post 2030.
More than 50 floating wind concepts are currently under development. While innovation is required to push performance, reduce weight, withstand harsh environmental conditions, and allow efficient operations, the wide range of concepts can also represent a barrier for the cost reduction needed in the industry to eventually attract subsidy-free investment. The number of different fabrication approaches can make it difficult for the supply chain to provide efficient fabrication facilities and standardize their logistics and processes.
One way the industry can tackle the challenges of expanding application, scale, and reducing costs without compromising safety, is through Joint Industry Projects (JIP’s) that aim to bring standardization across the floating offshore wind industry.
Floating wind farms, further from shore in deeper waters, will require floating substations with development of dynamic cables with higher voltage and power levels than currently available, as well as electrical equipment such as transformers and switchgear. One JIP is aimed at aligning best practice and closing the gaps in available substation standards to enable the scaling of floating offshore wind. Phase 1 has just been completed and confirmed the feasibility of floating offshore substations and export cables, identifying technology gaps and highlighting the maturity of AC solutions compared to DC. For Phase 2, new participants are called in to join the project, which will contribute to the 2024 update of industry standards for offshore substations and dynamic high-voltage export cables.
Another JIP focuses on mooring and cables. The growing floating offshore wind industry will require innovative solutions for floating structures, mooring arrangements, cable solutions, and materials. Mooring and cable equipment is a key cost driver within floating wind. A key task of the JIP is to provide new and valuable insights on load and capacity of these critical components; the recommendations will form the basis for tomorrow’s design requirements.
Finally, a recently launched JIP aims to optimize requirements for concrete floaters specifically tailored for floating offshore wind farms. Concrete floaters are a cost-effective and environmentally friendly alternative to steel floaters, particularly for larger turbine sizes. An alternative to steel, concrete engages a larger part of the supply chain in floating wind.
Ocean stakeholder collaboration
As offshore wind picks up pace, the demand for ocean space will also increase. It is essential that this expansion takes place in a safe, equitable, and sustainable manner. Therefore, it is critical that ocean stakeholders build strong working foundations. One way this is being facilitated is with a three-year scenario building project that aims to develop a scalable system model toolbox for determining and forecasting marine coexistence between different users of the ocean and marine ecosystems.
The project will focus on establishing a common knowledge base among ocean stakeholders, enabling them to identify synergies, resolve conflicts, and negotiate winwin solutions while safeguarding ocean health. The Utsira Nord floating offshore wind licensing area in Norway will act as one of the case studies in the development of the toolbox. The toolbox will be developed in a way that allows for scaling and adaptation to different regions and international settings, including the North American market.
Future marine spatial planning processes will increasingly need to emphasize coexistence with nature and other human activities. A toolbox will help offshore field developers and operators gain a competitive advantage by more quickly understanding how future competition for space will influence their overall risks and opportunities in relation to other ocean users, as well as the marine ecosystem. It will support strategic planning and stakeholder dialogues in connection with offshore field developments, marine spatial planning, and ecosystem management.
As part of the project, partners will seek to capture the impact ocean industries have on each other and the environment, as well as the cumulative effects from all industries combined. The goal is to contribute to trust and transparency in stakeholder dialogues in the early stages of project planning. Offshore wind developers can take advantage of new methods to plan for coexistence by taking a collaborative approach to accounting for the impact of future uncertainty on nature and the Blue Economy. Done right, floating offshore wind could play a less intrusive role when it comes to potential overlap with the interest of other stakeholders, such as not conflicting with fishing banks.
Supporting a clean energy future
To reach ambitious floating offshore wind targets, the industry must accelerate commercialization while managing risks related to cost, technical novelty, acceptance by other ocean stakeholders, and environmental impacts.
In the next five years, we expect continued technology development in floating wind to reduce cost, scale production, and broaden applicability.
As an increasing number of floating wind turbines come into operation, the industry will learn more about day-to-day operations, wind turbine performance, and events such as major component replacement. Those learnings will undoubtedly spur new developments, and play an important role in the transition to a cleaner energy supply.
Sigurd Solheim Pettersen is Senior Researcher, Bente Pretlove is Program Director, Ocean Space program, Group Research and Development, and Kristin Nergaard Berg is Technical Lead, Floating Offshore Wind, Energy Systems at DNV.
