Offshore wind energy is coming of age. Maturity, cost competitiveness, and reliability of the technology have improved significantly over the last 10 years – making offshore wind one of the most attractive clean energy technologies in the world today. Some of the main drivers which make offshore wind an attractive option include its minimal siting constraints and its proximity to load centers (big cities) along the coast. However, notable challenges such as water depth look set to become a problem of the past as constructing offshore wind farms at deep-sea sites gains traction.
Floating wind technology is set to open new opportunities for offshore developments, especially in Asian countries. In DNV GL’s recent Energy Transition Outlook 2020, the consultancy forecasts that the installed capacity of floating wind will grow from the present demonstrations of around 100 MW to 250 GW in 2050, a 2,000-fold increase, with the Asia Pacific region to develop more than half, or 153 GW.
So, how do we get there? Critical to kick start the nascent floating wind industry will be transforming past experience into expertise, risk management and defining the right standards. Because the forecast assumes that investors, developers, and regulators will build on best international practice and standards, governments should not create national sub-standards based on local preferences, but build on proven international experience. The risk to the industry of a national standards approach might be reduced speed of cost reduction and reduced efficiencies and economic scale, resulting in missed growth forecasts.
Learning from experience and demonstration projects
Growing an industry and innovating technologies at speed certainly entails many hazards. Industry players in the Asia Pacific region should therefore be aware of best practice and benefit from learnings not only from the European floating wind industry, but also from the associated offshore industries such as maritime and oil and gas, not least from (fixed) offshore wind.
For instance, the ability to handle differences, such as loads, redundancy and volumes, combined with the need for rapid costs reductions, is already well demonstrated at the European demonstration projects such as WindFloat Atlantic, Kincardine, Hywind Scotland and soon at the 11 turbines, 88 MW Hywind Tampen in Norway, already under construction and to be completed by 2022.
Video contributed by Aker Solutions – Hywind Tampen will be the world’s largest floating offshore wind farm and will reduce Norwegian CO2 emissions with the equivalent to the emissions from 100 000 cars.
Managing risk for complex assets
Floating wind has a far more complex risk profile than fixed offshore wind projects. Currently, we see more variation in project design and technologies deployed. And with each floating wind turbine comprising the floater, the turbine and the mooring system, there are more components at risk, more interfaces and more suppliers involved, many of whom may have limited experience in the field. The possibility that the turbine moves more than intended, the advanced coupling between components, and dynamic cables add risk to new floating wind projects.
As with any complex construction, the scale of floating wind projects presents another challenge. Creating large floating structures weighing more than 5,000 tonnes is not unusual for shipyards and the oil and gas industry, but manufacturing and installing more than 20 such structures in one project is new. Standards that consider new challenges and cover well-established manufacturing and installation processes will deliver such volumes while maintaining the necessary quality levels. Right now, concept developers such as Principle Power, Dr. Techn Olav Olsen, Aker Solutions, Ideol, Stiesdal and others are also developing manufacturing processes to handle both volumes, cost and quality in either steel or concrete.
Defining the right standards
Developing standards for the unique features of floating wind, such as the load regimes, the novel station-keeping systems and dynamic cables is another challenge that needs to be addressed early.
Floating wind platforms are not simply floating units with turbines on top. The turbine affects the floater’s stability which again impacts the turbine’s performance. Hence, they should be considered as an integrated whole. With turbine and platform manufacturers understandably wary of sharing sensitive information, integrated engineering might be a challenge. In that case, project certification offers a way to verify the interfaces between suppliers and ensure that engineering variations do not negatively impact other components and the whole construction.
Evolution for cost reduction
DNV GL has taken a leading position in developing requirements for floating wind turbine structures. Inspired by the first full-scale turbine, Hywind Demo, DNV GL issued its first guidelines in 2009. A full standard was developed in 2013 in close collaboration with ten industry partners. Building on experience from prototypes, research projects and the world’s first floating wind farm, Hywind Scotland, developed by Norwegian oil and energy major Equinor, issued a new update in 2018. Some of the key updates included optimized safety factors for fatigue, specific load cases related to loss of mooring lines, shared anchoring, and motion control. The standard fully aligns with the 2020 published class rules, which help yards to achieve cost-effective floating wind construction.
In the next update, to be published in early 2021, DNV GL looks at criteria for further cost reductions, creating standards that support the trajectory towards 40 EUR/MWh and the global growth of floating wind.
Risks associated with floating wind projects will need appropriate management and mitigation measures to bring comfort to financial investors. Certification and classification will be essential together with developer and contractor experience, technology choice, contracting structure as well as strong knowledge of the local conditions.
Utilising Norwegian experience and expertise
Based in Norway, developers of floating oil and gas production facilities, such as floating production storage and offloading (FPSO) units have flocked into the floating wind industry and are now competing to build the most efficient and low-cost solutions. From the start of the Hywind pilot on the west coast of Norway by Equinor some 15 years ago, through the project off Scotland and now at Tampen, costs of floating wind have dropped significantly. Other Norwegian industries with strong roots inflexible cables, concrete and steel construction, mooring, digital engineering, maritime O&M solutions, materials and coating, corrosion protection – and so on – are now engaging to deliver floating expertise to the European and Asia Pacific regions alike.
In conclusion, combining European expertise with the Asian steel, concrete and mass manufacturing knowledge, proper risk management and utilizing standards and certification guidelines will support Asia Pacific’s floating wind growth expectations.
Find out more about Floating Offshore Wind with Norwep by re-watching our session recording of Global Offshore Wind Summit – Taiwan 2020 below!
