Contributed by Anna Hilden, StormGeo
With advancements in technology and a steady reduction in costs, offshore wind is showing promise as a clean, cost-competitive energy choice. The industry is expected to increase by more than 20% annually over the next several years, with growth opportunities in both fixed and floating wind farms. This surge of development worldwide has come center stage with the Biden administration’s recently announced goal of achieving 30 GW of offshore wind generation by 2030.
As the wind power industry increasingly shifts to offshore locations, its resilience and future depend, in large parts, on an adequate preparation for and survival of severe weather events. Weather indeed plays an essential role in the operation and maintenance of offshore wind farms, and one of the most significant threats to these farms comes from hurricanes and tropical storms.
When preparing for severe weather conditions and planning to continue or shut down operations, receiving accurate and timely information is vital. Knowing what to expect and when to expect it allows operators and managers to make the necessary decisions in time to protect their employees and infrastructure. Because offshore wind farms are closer to shore, predicting waves, winds, and various weather conditions is more complex due to coastal effects. So, when safeguarding against hurricanes – and, in Asia, against typhoons – expert weather forecasting is a safety manager’s best friend.
Offshore weather forecasting can assist in all phases of a wind farm’s life span – from design and construction to operation and longevity planning.
Design When developing a wind farm in a region affected by hurricanes, it’s crucial to understand the extreme conditions that can be expected in the area. A thorough understanding of the conditions on-site enables you to determine the optimal dimension of turbines, foundations, and other structural elements that need to withstand even the most severe weather. Furthermore, extreme wind, waves, and precipitation can damage materials and equipment and threaten maintenance vessels and crews.
During the design phase, offshore wind developers should reach out to third-party weather intelligence services that can assess each project’s risks based on historical weather information. Some weather intelligence services have experts in offshore wind specifically, with access to suitable hurricane databases and analysis methods to quantify risks, according to each wind farm’s exact position.
Construction and operations Understanding the weather is equally important during wind farm construction and operations. Not only does the forecast determine when turbines can be installed and accessed for maintenance and repairs, but it also determines what output can be produced by turbines in which conditions. If there are stronger winds, you get more energy output than if there are weaker winds, so maintenance scheduling can be timed using forecasting when winds are low to minimize lost production.
All sides of the operation need accurate, continuous weather information to know when it’s possible to access turbines. project coordinators and crews need to know well in advance what weather conditions are expected to manage operations accordingly. Installation vessels need to determine if they can remain on-site in a jacked-up position, need to retreat to port, or – if there is no time to return to port – if they can evacuate crew via air. And helicopter pilots need accurate forecasting to know when they can safely fly, perform a helihoist, and land.
In some cases, a hurricane may be so severe that operations need to shut down, and people retreat to safety. For this to happen safely, operators must make critical decisions before the storm’s arrival. For example, can the installation vessel stay in the field with conditions remaining below the vessel’s survival limits? If not, is there enough time for the vessel to reach a port or safe shelter? To make these decisions properly, it’s essential to have detailed forecasts of the expected weather conditions, including risk levels, and direct and immediate access to expert forecasters.
While turbines are built to withstand extreme conditions, they will have wind speed limitations. Turbines are constructed to be self-guarding and have automatic systems to pitch out of the wind when maximum limits are reached so that the blades don’t catch the wind. This frees up an operator’s priorities to focus on safeguarding people and vessels.
Weather forecasting and time-tailored response plans can also help a business maintain its financial footing. Since output generation reflects on profit margins, timing a shutdown becomes vital not only for safety reasons but also to ensure maximum business continuity for the wind farm and its energy generation.
Future planning Wind farm projects can live for 30 years or longer, making long-term operations planning vital to longevity. Weather intelligence services can estimate how weather conditions, including extreme conditions associated with hurricanes, are expected to develop over the coming decades.
With a changing climate, there is an expectation of more frequent and higher-intensity storms in the future. Many forecasting services, such as StormGeo, use the UN Intergovernmental Panel on Climate Change’s (IPCC) official model projections to determine global trends in local weather conditions. When combined with local, historical data, future wind farm workability conditions and energy yield figures can be predicted.
When designing for the long-term, it’s essential to consider that insurers know what they’re getting themselves into and are covered for the various risks of hurricanes impacting a wind farm. Offshore projects come with their own, project-specific difficulties in inclement weather, and weather intelligence providers can help ascertain what those issues will be.
Offshore wind developers and operators in areas prone to hurricanes and typhoons regularly rely on offshore forecasting to keep their crews and assets safe. In Taiwan, for example, a country that is hit by an average of four typhoons every year, StormGeo works closely with the offshore wind industry to monitor tropical cyclone activity.
One example is a 32-turbine offshore wind farm off the coast of Taiwan, where StormGeo delivers forecasts and warnings up to seven days in advance of a tropical cyclone – two days ahead of what most forecasters provide. These detailed forecasts inform the project management team of when and where vessels will need to seek shelter and help project teams determine exactly when to take emergency action, such as stockpiling emergency supplies, restructuring travel plans, and securing goods at the dock.
When preparing for hurricanes, offshore wind developers and operators should essentially consider two things. First, remember to consider hurricane effects when designing the project. Team up with good consultants who understand the dynamics and impacts of hurricanes on an offshore wind project, have access to the right hurricane databases, and utilize adequate analysis methods to quantify risks.
Second, do not rely solely on publicly available hurricane information as this will be too general, too focused on onshore conditions, and mainly geared towards the general public. Instead, use an experienced weather forecast provider with direct access to a dedicated forecaster. These can tell you well in advance not only that there is an incoming hurricane but also what effects the hurricane will have at your specific site and project.
Weather intelligence service providers partner with wind farms issuing forecasts as soon as a disturbance, which might evolve into a tropical storm, is detected. Each storm’s development and characteristics are monitored closely in relation to the client’s sites, including wind and wave fields, precipitation, flooding of ports, and more. Forecasting can be done up to seven days in advance, allowing managers to make operational decisions with time on their side.
Many weather intelligence providers offer 24/7 hotline support to clients, ensuring experts are available for advice at any time of day.
About the author
Anna Hilden is Global Industry Manager of Offshore Wind for StormGeo, a 24/7 weather intelligence provider. With over a decade of industry experience, Anna provides advanced meteorological services to clients in the renewable energy sector for safe and more efficient offshore operations. For more information, visit www.stormgeo.com.