IEA-Wind Task 31 WAKEBENCH 2 (2015-2018)

Verification, Validation and Uncertainty Quantification (VV&UQ) of wind farm flow models. The purpose of the project is to improve wind farm modeling techniques and provide a forum for industrial, governmental and academic partners to develop, evaluate and improve wind farm models. While Task 31 Phase 1 was limited to the wind farm (microscale) scale, Phase 2 will extend the scope to mesoscale and near-wake modeling in order to cover all the relevant atmospheric scales related to wind power meteorology. This will allow a more comprehensive approach to the wind farm integrated design process, facilitating the exchange of knowledge among various research communities: meteorologists, resource/site wind engineers and wind farm/rotor aerodynamicists. The focus will still be placed on wind resource assessment, site suitability and wind farm design but allowing for a larger variety of modeling approaches. Some benchmarks will also be explored in finer detail to better quantify the uncertainty of a range of models for different phenomena.       

Following Task 31 working procedures, the work will be organized around model intercomparison benchmarks, established around well-defined test cases from research and industrial measurement campaigns. The model verification and validation framework established in Task 31 will be adopted and extended to account for new modeling approaches. Furthermore, uncertainty quantification on wind assessment will be also considered as the final outcome of the model evaluation process. As a result, a framework for model verification, validation and uncertainty quantification (VV&UQ) will be defined as a new edition of the Model Evaluation Protocol (MEP) delivered in Task 31 and integrated in the web portal. 

The new Task is timely not only to keep continuity on the activities of Task 31 but also to coincide with large research projects taking place over the next few years in Europe (ERA-Net Plus on the New European Wind Atlas, NEWA) and the USA (Atmosphere to Electrons, A2e) with focus on multi-scale model-chain development through high-fidelity experiments. It is expected that these projects will complement each other and will make use of this IEA forum to exchange knowledge and disseminate results to the international community.

From an industry perspective it is worth mentioning that this Task will contribute to the pre-normative activities carried out in the context of the IEC-61400-15 working group dealing with “Assessment of site specific wind conditions for wind power stations”, that was initiated in 2014.

It is also a good opportunity to enhance cross-Task collaboration with neighboring groups like Task 29, dealing with rotor aerodynamics, Task 30 dealing with offshore design codes and Task 32 dealing with Lidar measurements.

If you want to participate in Task 31 please contact your national IEA-Wind member and any of the Task Operating Agents: Javier Sanz Rodrigo (CENER), Iván Moya Mallafré (CENER), Patrick Moriarty (NREL) and Pierre-Elouan Réthoré (DTU Wind).

Recent News

Phase 3 approved, to kick off in Milano on June 19, 2018


The third phase of Task 31 was officially approved by the IEA-Wind Executive Committee during the last meeting in Belgium on the 15th of May. This three-year extension will have a kick-off meeting on the 19th of June in Milano, right before the Torque Conference hosted by Politecnico di Milano. The next phase will continue working on the development of an international framework for verification and validation of wind farm flow models. There will be more focus on aligning this framework to industry by working more closely with IEC working groups developing standards for wind resource…


Final Meeting of Phase 2 in Tokyo, April 17-19, 2018


The final meeting of the second phase of Wakebench will be hosted by the Wind Energy Institute of Tokyo next April 17-19, 2018. The evnet will start with an open-day symposium where Task 31 participants will exchange with the Japanese community on wind farm flow modeling. The following two days will be devoted to discussing a proposal for a Task extension to three more years. The work plan will exploit recent experiments from the NEWA and A2e research initiatives to establish a unified validation strategy for external wind conditions and wind farm wake models. This strategy will be aligned…

Pawel Gancarski

The Fifth Symposium on OpenFOAM in Wind Energy (SOWE 2017)


The Fifth Symposium on OpenFOAM® in Wind Energy (SOWE 2017) is hosted by the Department of Wind Energy at CENER (National Renewable Energy Centre of Spain). As in the previous editions, the symposium offers a space to share the latest developments based on OpenFOAM® for Wind Energy applications. The symposium brings together experts, beginners, developers and final end users to discuss the research results and techniques to solve the new demands of the Wind Energy sector.

Details on the conference can be found here…


Last 30th of October we had a joint workshop with Task 32 to gather experimentalists and model developers to discuss how lidar-based experiments are used to analyze wind turbine and wind farm wakes and how this data can be used for wake model validation.

Further collaboration with Task 32 will be pursued by organizing a benchmark around a lidar experiment conducted by ForWind in the Alpha Ventus offshore wind farm in 2014 that was also reproduced with a LES model. A turbine model defined by Task 30, using…


Next Meeting: 2nd Annual Meeting, Visby, 29 May 2017


Our next annual meeting will be hosted by Uppsala University campus Gotland in Visby, Sweden, on the 29th of May 2017. The meeting is right before the Wake Conference 2017. Please consider submitting your work to the conference track to be included in a special session on Wakebench (abstract submission by December 2, 2016).  

Carbon Trust has granted CENER, DTU and NREL access to the Offshore Wind Accelerator experiment at the Rødsand 2 windfarm in Denmark. Cornell University and NREL will aslo participate in the project as subcontractors.

The experiment consists on two long-range scanning lidars and two pairs of nacelle-mounted short-range lidars besides a boundary-layer met mast. The campaign is one year long.

Initial analysis of the data will look into the characterization of…

Pawel Gancarski

11-June-2015: Wakebench Phase 2 kick-off


The second phase of Wakebench had its kick-off meeting at the Gotland Campus of Uppsala University, right after the Wake Conference 2015. The meeting reviewed the highlights of the first phase of Task 31 and discussed the challenges for the new phase. A topical expert meeting organized within IEA Task 11 was also held to launch a new work package in Task 31 about uncertainty quantification of wind farm flow models.



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