WindEurope 2025 brings together industry and society's attention on wind power in Europe.First partIn this article, I have reported on the state of the exhibition and the trends I felt in the fields of business, policy, and society. In the second part, I will report mainly on technical presentations and research trends.
table of contents
• "Floating: is it coming or isn't it?" - Is floating coming or not?
• "Resource Assessment Part 1: LiDAR" - Wind condition survey Part XNUMX Lidar
• Featured Poster Session 1: Turbulence Intensity Simulation by MPAS/WRF
• Poster session of interest: Japanese observation data evaluated as a basis for complying with international standards
• The cutting edge of wind observation seen from the exhibition booth
• Conclusion
"Floating: is it coming or isn't it?" - Is the floating type coming or not?
The most memorable session this year was "Floating: is it coming or isn't it?" This session was titled "How can we develop floating offshore wind farms in the Canary Islands, a Spanish territory?", and began with a panel discussion featuring speakers from Norway, France, and other countries. These countries are accelerating the development of floating offshore wind farms, as there is limited room for fixed-bottom development in the surrounding waters.
What was impressive was that the title of the session itself embodied the typical European style of encouraging lively discussion. At first glance, it seemed like the tone of the discussion was questioning the merits and demerits of introducing floating systems, but in light of the maturity of the actual technology and market, the discussion had progressed from a question of "will it come or not" to a phase of "it's already here" and "how can we expand it?"
Certainly, the high construction costs of floating offshore wind power are cited as a barrier to its widespread adoption. However, similar discussions must have existed in the early days of onshore wind power and fixed-bottom offshore wind power. Looking back at this history, I feel that floating systems are also an extension of existing technology, and that their future adoption is inevitable.
"Resource Assessment Part 1: LiDAR"— Wind Survey Part 1: Lidar
This article introduces some of the latest wind research findings presented in the session on Doppler lidar observations.
Improved accuracy of turbulence intensity measurements
VAISALA, developer of the pulsed vertical lidar WindCube, introduced two techniques aimed at improving the accuracy of lidar measurements of turbulence intensity.
One is the Interbeam IT Reconstruction method, which reconstructs line-of-sight wind speed, and the other is the Machine-learning TI method. When evaluated with reference to the turbulence intensity of a three-cup anemometer, both methods were shown to measure turbulence intensity with higher accuracy than conventional methods.
New applications of scanning lidar surveys
Additionally, there were two presentations on scanning lidar.
The first is about use after operation has started, which is practiced in Europe. In Japan, it is mainly used to investigate wind conditions before the construction of offshore wind farms in order to measure turbulence along the coast. In Europe, it was announced that scanning lidar is actively used in investigations after operation has started, such as directly measuring the wake of wind turbines at offshore wind farms and using that to evaluate wake models. The use of scanning lidar during the operation phase is an initiative that could be considered for adoption in Japan in the future.
The other was about how it is used in the evaluation of wake models. A case study was reported in which scanning lidar data was used to verify a wake model that reproduces the wake of a wind turbine. The results showed that the wake model (TurbOPark & Park model) had a higher velocity deficit rate than scanning lidar data, meaning that it overestimated the wake. I realized that the ability to use actual data to evaluate wake models at sea, which is difficult to do in Japan, is a major strength of Europe.
Featured Poster Session 1: Turbulence Intensity Simulation by MPAS/WRF
In the poster exhibition, attention was focused on research into turbulence intensity simulation as an effort to improve the accuracy of wind resource simulations.
Among them, the most notable wasResearch using the meteorological model "MPAS (Model for Prediction Across Scales - Atmosphere)"MPAS is an irregular, high-resolution, zero-horizontal resolution (mesh) model that has been attracting attention in recent years as a next-generation meteorological model alongside WRF (Weather Research and Forecasting model).
In this study, turbulence intensity was estimated using two methods, the TKE method and the Kaimal model, from the output results of MPAS and WRF. As a result, it was found that MPAS had a high degree of agreement with observed values in the wind speed occurrence frequency distribution, and calculated higher turbulence intensity than WRF even when using the same turbulence calculation method.
The results showed that the smallest absolute error was obtained especially in the high wind speed range of 7.5 m/s or more. In addition, by using the Kaimal model in combination, the tendency of MPAS to overestimate was suppressed, suggesting its potential as a more practical model.
This research focuses on floating offshore wind power development, and can be said to be an advanced initiative from the perspective of obtaining turbulence intensity data in the open ocean, where wind observation is difficult. It is a technology trend that we will continue to keep an eye on.
Related articles about WRF can be found here
https://rera-tech.co.jp/technote18/
Featured Poster Session 2: Japanese observation data evaluated as a basis for complying with international standards
Poster presentation by EOLOS:Measurement Uncertainty for the Envelope of Operational Conditions of the EOLOS Floating Lidar SystemAt the event, the company reported on the latest results of performance verification of the floating LiDAR "FLS200," which it developed and provides.
This research quantitatively evaluated the observation accuracy of floating LiDAR in accordance with the international standard IEC 61400-50-4, and the analysis was based on more than 7 validation data sets that the company has conducted at seven locations.
Specifically, the EOC (Envelope of Operational Conditions) was compared with the SMC (Scenario for Measured Conditions), which is actual operational data, and it was confirmed that the average SMC value for all items was within the EOC range. In particular, the FLS motion characteristics (maximum pitch and roll) and wind speed vertical distribution (wind shear) also showed stable behavior, and the results were in line with Scenario A (conditions in which classification uncertainty is considered to be 61400) defined in IEC 50-4-0.
In addition, it was clarified that the assessment method based on IEC 61400-50-4 has a smaller total uncertainty value, generally less than 61400%, compared to the conventional assessment method (IEC 50-2-2.5), demonstrating that the method enables more reliable assessment.
The observational data used in this verification included data from JapanMutsu Ogawara Port Offshore Wind Condition Observation Test SiteThe site included data obtained from the 2016 JSPS International Conference on Marine Science and Technology (MSMT), which was established and is operated by Kobe University, with technical support from ReraTech. The fact that Japanese observation data was used to evaluate the reliability of international standards is of great significance in terms of contributing internationally to future floating measurement technology.
The cutting edge of wind observation seen from the exhibition booth
In the first part, we touched on the state of each company's exhibition booth. In the second part, we will introduce three particularly impressive companies' booths that introduced technologies and operational examples related to wind observation.
■nvisionist (Greece)
nvisionist is a company that develops bird collision avoidance systems for onshore and offshore wind power plants and airports, using radar and cameras to recognize birds. By attaching the cameras to mast towers during wind observations, they monitor nearby birds.
In Japan, it is envisioned that the system could be used to conduct demonstration experiments in collaboration with the Wild Bird Society at the Mutsu Ogawara offshore wind observation test site.
■Whiffle (Netherlands)
Whiffle, a spin-off of Delft University of Technology in the Netherlands, is a company that provides highly accurate weather simulations on the cloud. The company's unique feature is that it can perform calculations and obtain data on demand from a cloud platform. Until now, wind simulations using WRF have been mainstream in Japan, but the emergence of this service is likely to be an opportunity to reconsider how research and practice are conducted.
■DHI (Denmark)
DHI, a Danish company with offices around the world, is a consulting company specializing in oceanographic phenomena. In the past, they provided assistance with oceanographic analysis when we installed a floating lidar system at the Mutsu Ogawara offshore wind observation site.
At the exhibition booth, a DHI representative asked, "Are there any organizations in Japan that continuously observe wind conditions and provide data?" to which we replied, "The Mutsu Ogawara Offshore Wind Condition Observation Test Site is the only example." This exchange showed that Japan's observation system is attracting international attention.
To the end
The debate surrounding floating offshore wind power is shifting from "should we introduce it?" to "how can we expand its implementation?" In this context, the advancement of wind observation technology, the development of analytical models, and the refinement of evaluation based on international standards give the impression of greatly boosting the technological foundation. In the future, in Japan too, the key will be to design systems and strengthen observation structures with an eye toward the implementation stage. This was an opportunity for us at ReraTech to reexamine what role we can play as a bridge between academia and industry.
As wind condition consultants, Rera Tech Inc. will conduct optimal wind condition surveys that combine "observation" and "estimation" for wind power generation. Please feel free to contact us if you have any inquiries regarding wind conditions.