The 2024th Wind Energy Utilization Symposium held on November 11th and 28th, 29 (hosted byJapan Wind Energy Society) was attended by members of Rera Tech Inc. This symposium is an important forum where the latest academic trends in wind power generation in Japan are gathered. In this article, we will introduce the topics that Rera Tech Inc. members Konagaya, Misaki, Nakazato, and Shintaku focused on.Technical NoteWe will introduce it in the following. Please take a look.
participant
Konagaya: CEO of Rera Tech Inc. As an academic researcher at Kobe University, he also conducts research on offshore wind condition surveys.
He also serves as director of the Mutsu Ogawara Marine Meteorological Observation Center (Inc.).
Misaki: In charge of wind simulation and analysis. Also serves as an academic researcher at Kobe University.
Nakazato: Responsible for a wide range of wind observations, analysis and simulations.
New House: Responsible for wind condition simulation and analysis.
Uncertainty assessment of practical dual scanning lidar observations
Nakazato:While the number of research projects in the field of wind conditions is increasing year by year in the symposium sessions, this year one session was set up on "lidar," which gave a real sense of the development of research on lidar in Japan.
In particular"B1-3: Accuracy verification of line-of-sight wind velocity using dual scanning lidar and estimation of site-specific measurement uncertainty"The session was impressive. It was very interesting to see that overseas test sites and overseas models were used to evaluate the uncertainty in dual scanning lidar observations.
It is noteworthy that the paper lists two methods for evaluating the uncertainty of dual scanning observations: White Box testing and Black Box testing. It is useful to see that the paper quantitatively evaluates the advantages and disadvantages of each method.
There are few examples of such evaluations in Japan. In the future, we will refer to the procedures presented in this study andMutsu Ogawara Offshore Wind Observation Test SiteHowever, I wanted to tackle the uncertainty assessment of dual scanning lidar observations.
Misaki:In this announcement,DNV/Vaisala GuidelinesBased on this, he explained the methods and results using specific observation data. The content was very practical for practitioners, as it is directly applicable to the field.
Konagaya:Research and development into the measurement of dual scanning lidar itself is a maturing field. This time, they went a step further and also presented error evaluation and correction methods for measuring turbulence intensity on the ocean.
Furthermore, Misaki's research presentation from the previous yearFollowing this, there was progress in research on the trade-off between observation accuracy and data acquisition rate, which gave a sense of the development of observation methods.
"Wake" becomes a hot topic
Konagaya:Another distinctive feature was thatNEDO ProjectWith the start of the new academic year, there have been many presentations on research into wakes. I will be keeping a close eye on the results and trends of these research projects, as they are an important topic that affects wind conditions.
Misaki: "B2-4: Verification of the exclusion of wind turbine wake effects from wind observation data using actual power generation data"In the presentation, a specific correction method was proposed using vertical lidar data and airflow analysis results for cases where wind mast observation data is affected by the wake of nearby wind turbines. It was a topic that is expected to be applied to practical applications.
Data corrections are necessary not only for the wind speeds presented in this presentation, but also for wind direction and wind speed standard deviation, and we look forward to further research and development in the future.
Latest information on wind observations and simulations
Konagaya:In offshore wind simulation, a wide range of topics were covered in research using the weather simulation system WRF, including that conducted by Kobe University.
Specifically, a combined method with satellite observation data (B3-4 Study on Estimation Technology of Hub-Height Wind Conditions in the Open Ocean (Part 2) - Effect of Satellite Observation Frequency on Estimation Accuracy -), Accuracy verification of the Japan Sea coastal area (B3-5 Consideration of topographical effects based on multiple offshore wind observations and accuracy verification of WRF), discussion of the representative radius of the observation point (B3-6 Study on coastal wind estimation using WRF and hourly vector correction: Initial study on expanding the method considering representativeness of observed values) Japan's first offshore wind condition map that consolidates all the information needed to plan offshore wind power projects.NeoWinsThese include improving the accuracy of estimates in preparation for the revision of the standard (※1).
Nakazato:What impressed me most about the onshore wind observations was"B4-6: Comparison of atmospheric stability using data from a 200m-tall meteorological observation tower - Comparison of typical wind observation altitudes in Japan and rotor surface altitudes -"This was the announcement.
"We have rarely seen verification cases using high-altitude masts, so the results of analyzing long-term observation data are extremely valuable. The quantitative evaluation of atmospheric stability conducted in this study is extremely important for the development of offshore wind power generation and the increasing size of wind turbines, and we have reaffirmed the importance of introducing it domestically."
Konagaya:As a joint research project involving Rera Tech Inc. in this field, a presentation was made on snow and ice accretion on anemometers (B4-3: Evaluation of anemometer stoppage and deceleration conditions due to ice and snow accretion and verification by wind tunnel experimentsRegarding issues related to the accuracy of winter wind speed observations, the content that pointed out the risk of underestimation is extremely important, and we believe that this is an issue that we will need to continue to address next year and beyond.
*1 About NeoWins revision: https://www.nedo.go.jp/koubo/FF3_100397.html
50 years since the Sunshine Project: Learning about wind conditions, past and present, from our predecessors
Konagaya:This year marks the 2th anniversary of the launch of the Sunshine Project (※50), and the invited lecture introduced pioneering research and development and efforts toward the introduction of wind power generation in Japan.
The wind maps and wind observation methods that we take for granted today were also established through the efforts of our predecessors. During the lecture, I felt the need to re-learn the history of accident responses due to typhoons and turbulence intensity that are unique to Japan, and the establishment of safety standards.
New house:A lecture by Professor Shibata, who has been involved in wind turbine development at Mitsubishi Heavy Industries for many years and is currently teaching at Osaka University."Large-scale wind power generation technology development"is particularly memorable.
In recent years, wind turbines have become significantly larger, but during the presentation it was estimated that for wind turbines of 20 MW or more, the LCoE (※3) will not decrease significantly as the size increases, and it was suggested that the size of wind turbines may level off at this point.
*2 Sunshine Project: A new energy technology research and development plan formulated in 1974 in response to the first oil crisis in order to reduce Japan's excessive dependence on oil and resolve the serious environmental problems.
*3 LCoE: Levelized Cost of Electricity. All costs incurred from planning to decommissioning of a power plant are evaluated on a present value basis and divided by the amount of electricity generated on a present value basis.
Throughout the symposium
Konagaya:Through this symposium, we felt the progress of research and development in the fields of offshore wind observation and numerical simulation. In particular, the turbulence intensity measurement by Kobe University using LIDAR is an important technology for offshore wind condition surveys. ReraTech would like to collaborate with Kobe University in research and development aimed at practical application.
There were also many new proposals for verifying the accuracy of LIDAR and for correction methods, and we felt that we would like to use the Mutsu Ogawara offshore wind observation test site to quickly advance technical demonstrations.
Misaki:Regarding wind surveys, there were many presentations on dual scanning lidar system observations, but very few presentations on floating lidar system observations.
Considering the further spread of floating offshore wind turbines, the importance of floating lidar system observation technology is expected to increase, and we hope to see an increase in related presentations in the future.
ReraTech has also reaffirmed the need to contribute to technological advances in the industry not only by utilizing the knowledge it has gained through past projects, but also by actively participating in floating lidar system observations from an R&D perspective.
Nakazato:In particular, vertical lidar and dual scanning lidar are being put to full-scale commercial use, and various approaches to operational challenges and improvements were proposed.
On the other hand, in Japan, floating lidar systems and nacelle-mounted lidar are still in the research and development stage, and there are still few examples due to the many technical challenges and operational constraints.
In the future, Rera Tech Inc. would like to participate in research and development projects using these technologies, not only to evaluate the technology but also to consider identifying issues and formulating a roadmap for operation.
New house:Among the research presentations, the wake-related presentation from Kyushu University was impressive. Also, in commemoration of the 50th anniversary of the Sunshine Project, the lectures by the great professors who built the early days of the wind power industry in Japan left a deep impression on me.
In particular, in the case of Fuji Heavy Industries, which took on the challenge of entering the wind turbine manufacturing industry, where it is difficult for new entrants, an episode was introduced in which a group of young employees shaped their independent learning and turned it into a product, and I realized that the importance of enthusiasm and industry-academia collaboration remains unchanged to this day. In my current work, I would like to steadily overcome each challenge one by one.
As wind condition consultants, Rera Tech Inc. will carry out optimal wind condition surveys that combine "observation" and "estimation" for wind power generation.
reference
Takeyuki Misaki, Teruo Osawa, Mizuki Konagaya, Susumu Shimada, Sensitivity experiment on observation settings of scanning lidar, Proceedings of the 45th Wind Energy Utilization Symposium, 2023, pp.17-20.
https://www.jstage.jst.go.jp/article/jweasympo/45/0/45_17/_pdf/-char/ja
Mutsu Ogawara Offshore Wind Observation Test Site
https://mo-testsite.com
DNV, Vaisala, Guidelines on dual scanning lidar measurements for wind resource assessments Rev. 0, 5th March 2024
https://www.vaisala.com/sites/default/files/documents/WEA-ERG-Whitepaper-Guidelines-dual-scanning-lidar-measurements-WRA.pdf
NEDO, Sunshine Project 50th Anniversary Special Website, Last updated: October 2024, 10
https://www.nedo.go.jp/activities/sunshine50th.html