DNV GL, an independent energy experts and renewables certification body, has launched a Joint Industry Project (JIP) with global partners to develop a new best practice for the validation of turbulence models.
According to DNV GL, the JIP “Validation of Turbulence Models” aims to create a better understanding of turbulence modeling to reduce uncertainty in the design of wind farms. By jointly developing guidelines in the form of a best practice document, the project will improve accuracy on site-specific load assessments, leading to a reduction in the cost of wind energy, says the company.
To design wind turbines and wind farms, the industry currently relies on wind turbulence models that were developed decades ago when wind turbines were smaller than modern turbine types. With the increased size of turbines, current turbulence models result in large fatigue load variations with differences of up to 20%. Furthermore, existing turbulence models are often insufficiently applicable to other site conditions beyond flat terrain and neutral stability.
DNV GL says the JIP will collect onshore and offshore wind measurement data from more than 30 global sites, considering onshore, offshore and coastal influences in the analysis. By validating key turbulence parameters and evaluating their load impacts, the JIP will provide guidance for optimal wind turbulence design and site assessments.
The participants include a range of wind farm developers, wind turbine manufacturers and research institutes:
- Christian Michelsen Research AS;
- DONG Energy Wind Power;
- DTU Wind Energy;
- Gamesa Innovation and Technology;
- GE Global Research;
- National Renewable Energy Laboratory;
- Siemens Wind Power AS;
- SSE Renewables Developments LTD;
- Statoil Petroleum AS;
- TechnoCentre Éolien; and
- Vattenfall AB.
Kenneth Thomsen, head of section for wind turbine loads and control at DTU Wind Energy, has high expectations for the JIP project on turbulence: “In the design of wind turbines, the critical factor is often the wind inflow modeling, and often, it is a challenge to model the wind and turbulence correctly at a specific site with only a limited amount of measured data. In this project, we aim to establish recommendations for using existing wind and turbulence models, but also for further development of these for future use.”
Jose Simon, senior engineer at DNV GL – Energy Renewables Certification, responsible for setting up this JIP, commented, “In the planning process, it became apparent that there is currently area for improvement on turbulence modeling, especially for site-specific turbulence. Talking to different wind industry stakeholders during the preparation for this project highlighted the necessity of aligning industry expectations on turbulence in a best practice. To gain a deeper understanding of turbulence modeling, the industry needs to collaborate, and this project provides a unique platform to do so.”