High-resolution weather models are gaining new traction in Asia, where offshore wind development is booming. As China surpasses the UK and Germany as the world leader in the offshore wind sector and Taiwan grows rapidly, both countries are seeking weather models that give a more realistic weather picture.
Wind turbines are burgeoning on the east coast of China, along the Taiwan Strait and in northern Taiwan. These areas have ideal wind and wave conditions for offshore wind as well as the requisite shallow waters. However, these areas also have complex tide, wind, wave and swell patterns. This is where high-resolution weather models come into play.
“If weather conditions are particularly difficult to understand or forecast, a high- resolution model makes a big difference,” says StormGeo’s Vice President of Renewables, Jostein Mælan.
In a high-res weather model, more computer power is used to add grid cells to standard numerical weather models. Mælan likens the difference between the two models to building the Eiffel Tower out of Lego pieces versus shipping containers. It’s the small pieces that produce a more realistic model, which then gives a higher quality forecast of weather conditions.
Mælan stresses the importance of mapping the terrain correctly. “When we need to understand the complexities along a coastline, we calculate the weather from a higher resolution so that we can map the terrain closer to reality. It can be easy to miss small fjords or the tops of mountains, but winds travel into a fjord, not across it, and wind speed increases over the tops of mountains. If we have more detailed representations of these features, we can explain the wind patterns so much better.”
In the above portal windows, you can see the difference between the global model and high-resolution model over Taiwan. The dark blue areas in the high-res window show high winds around the Taiwan mountains that are not shown in the global model. You can also see that there is a slight variance in wind direction between the high-res window and the rest of the map. Seeing these local conditions and patterns displayed accurately is crucial for offshore wind farms.
StormGeo has used high-res modeling for the past 15 years in the Caspian, Barents and North Seas, where special conditions such as icing need to be considered. The models have also been used in relation to wind farms in Brazil and continental Europe on both sea and land.
StormGeo’s R&D department is working full-speed to build, set up, run and fine-tune the models to fit the purpose for offshore wind. The beauty of this type of modeling is that it can be tuned to fit different purposes. For example, when used in insurance or agriculture, the model can be tuned to better understand temperature differences. In this case, the prioritized factors are wind, waves and swells. These factors not only enable the offshore wind projects to operate efficiently, but also aid during the development, installation and production estimating phases.
“At the moment we are involved in 100% of the active offshore wind projects in Taiwan. We have also had meetings with several companies in Asia, looking at how we can phase our competencies into Vietnam, South Korea and Japan,” says Mælan.
StormGeo has been running a test for its high-res model in the Strait of Taiwan over the past several months. The aim is to show that this model is better than those currently available.
“At this stage it’s looking very promising,” says Mælan. “With many companies in the region asking us for high-res models, it’s gratifying to now have something to show them. But we need to continue to test and verify to show that this model is valid. However, meteorologists already using this model to forecast for the area are very positive about it.”
StormGeo has been running two highly regarded high-res models for nearly 20 years—WRF, which models the atmosphere, and SWAN, which is used for waves.
“You have different competencies in different companies and I think we are among the best in setting up, using and having the experience with this type of model. We also complement the local patterns from the models by combining them with the skills and knowledge of our meteorologists for the specified area.”
While the research and development for the high-res model starts in Bergen, Norway, StormGeo’s foray into the Asian offshore wind market is a truly global effort, with forecasters working from Dubai and tropical forecast competence coming out of Houston.