To commercialize our power system with floating offshore wind, it must be deployed and generated in areas of deeper water with higher, more consistent wind speeds. The list of countries keen to assess its feasibility outside Europe includes South Korea, Japan, Taiwan, and the US, where the Department of Energy is investing more than $100 million into researching, developing, and demonstrating floating offshore wind technology, with a particular eye on California. 

In fact, the Biden administration has increased the Wind Energy program budget from $60 million to $200 million next year, a portion of which will help develop designs for cost-effective floating platforms. Floating offshore wind is also being explored for its potential in converting seawater into green hydrogen for storage and export.   

ON-DEMAND WEBCAST: Floating offshore wind: Here’s how the U.S. can take the lead

Before floating offshore wind turbines can be deployed on a commercial scale, there are technical issues to resolve that will require innovative solutions from developers, manufacturers, and the supply chain. According to the Floating Wind Joint Industry Project (FWJIP), an R&D initiative between the Carbon Trust and 17 international offshore wind developers, these challenges are common to several floating wind projects and suitable for industry-led collaborative R&D. They include heavy lift maintenance and the logistics of this for wind farms further away from ports, tow-to-port maintenance, and moorings in challenging environments. Water depth, whether it’s very deep or very shallow, can be problematic, as can seismic environments and certain seabed conditions.  

Cabling is another critical concern as floating offshore wind needs to utilize dynamic power cables that float along with the foundation. Unlike conventional submarine cables, dynamic cables are subject to various stresses arising from platform movement, tensile loads in deep water, and the hydrodynamic stresses from waves and currents. This cabling technology is based on the experience from the oil and gas industry, but submarine power cables tend to carry higher voltages, increasing the insulation requirements and thereby the overall weight.

As a result, engineers would need to make additional design considerations for cable strength, flotation, flexibility, and temperature regulation. New generation dynamic cables would be required to handle the increased power output from newer more powerful wind turbines that are planned to be installed in the coming years.  

With testing and trials underway for decades, recent technological innovations in floating offshore wind have begun to emerge that many hope will further reduce and ultimately minimize the risks associated with their massive scale, hydro/aerodynamics, and instability. In past years, floating offshore wind systems were initially tested in windy and relatively shallow waters such as the North Sea. But now developers have found technical solutions to place floating offshore wind turbines in areas that used to be unfeasible—deeper, more windy areas where 80% of the world’s offshore wind blows.  

For instance, the Windfloat Atlantic floating offshore wind project that is operating 20 km offshore Viana do Castelo, Portugal (pictured above) is the world’s first running semi-submersible floating platform that deploys standard offshore wind turbines in waters deeper than 40 m. 

As an engineered solution customizable to specific project requirements, including wind turbine generators, metocean conditions, infrastructure constraints, and project size, the technology enables flexibility given the number of design variables (column spacing, column diameter, draft, truss diameter, heave plate architecture, etc.). The system can generate enough electricity for approximately 60,000 households and is a major milestone in the technological advancement of the offshore wind energy industry.  

More innovations continue to overcome floating offshore wind challenges, including building the foundation at the quayside. The TetraSpar Demonstration Project, the world’s first full-scale demonstration of an industrialized offshore foundation (pictured above) carried out in a partnership between RWE, Shell, TEPCO Renewables, and Stiesdal, achieved a range of world firsts, including the automated factory manufacturing of the foundation components, and the welding-free assembly at the quayside, reducing time and energy. The TetraSpar is currently in full operation at a water depth of 200 meters. 

There are more opportunities for innovation in a number of related areas going forward. Some interesting developments include wind farms integrated with hydrogen-producing facilities and prototype airborne wind turbines, like airships. Last year in Holland, the largest wind farm (fixed) on fresh waters inland came into operation.  

Recently, Offshore Renewable Energy (ORE) Catapult, the National Decommissioning Centre (NDC) and the School of Engineering at the University of Aberdeen have joined forces in the UK to work on three projects focusing on floating offshore wind development.

The first project will study marine operations related to the installation and maintenance of floating offshore wind turbines utilizing NDC’s advanced simulation systems. The second project aims to develop a tool capable of suggesting optimum design solutions for platforms, mooring, and dynamic cable systems for different site conditions and budgets. The last project will investigate the interaction of floating offshore wind farms with the marine environment using the collaborative knowledge of various environmental stakeholders and organizations.  

GO DEEPER: U.S. offshore wind supply chain: By the numbers

Pressure will grow in the coming years to produce energy away from the land. Renewables, whether onshore wind or solar, use a lot of land, and this can conflict with agricultural or housing needs. Not to mention the associated sound and visual impact in some locations. These concerns combine with regulatory pressures to decarbonize and increasing public unease about emissions and climate change.  

However, given floating offshore wind turbines are arguably less intrusive on the human domestic environment than those that are fixed, this may allow more large-scale developments with less impact on agriculture and residential developments, but the industry and technology are so new this remains to be seen, particularly given the expected required expansion of inter-country and inter-state grid connections, and port and manufacturing facilities onshore to improve supply-chains. 

As the industry emerges from the realm of R&D, prototyping, and feasibility studies, there are now calls for policymakers to commit to it with a supportive regulatory framework, investment in infrastructure, and funding and investment solutions that will support the commercial roll-out.

Only then, say industry experts, can the seemingly limitless potential of FoW become cost-effective to harness and fully integrated into the energy market.  

About the author

Faiz Abdulla is a Senior Underwriter at Allianz Global Corporate & Specialty which is a leading global corporate insurance carrier. As part of the Chief Underwriting Office within the Energy & Construction line of business, Faiz has a global role with a focus on steering the insurance portfolio and underwriting strategy of Power and Oil & Gas business. This includes construction and operational risks both onshore and offshore as well as renewable power. Faiz has been in the insurance industry for around 15 years. Before Allianz, Faiz worked with notable industry players such as AXA XL and Willis Towers Watson. Faiz is an engineer by background with a Master’s degree in management and professional qualifications from leading insurance institutes including the Chartered Insurance Institute of the UK.