MS#01.7 New methods for turbulence measurements and models in offshore wind

J. GOTTSCHALL¹, F. ROUHOLAHNEJAD¹, M. THIÉBAUT²
¹ Fraunhofer IWES|² France Energies Marines

Wind resource, metocean and extreme conditions

This mini-symposium is organized by the partners of the project “NEMO” -- a bi-national joint project led by Fraunhofer IWES and France Energies Marines, started in September 2023 and with a project duration of three years. In this mini-symposium, we want to introduce the project and its objectives, present preliminary results and invite further contributions on the covered topics from speakers outside of the consortium. Submissions on the project topics -- methods for turbulence measurements (incl. fixed profiling, floating and scanning lidar systems) and models (incl. WRF and LES modelling) in offshore wind -- from any organization are very welcome.

Please see the following project summary for more information on NEMO or https://www.iwes.fraunhofer.de/de/forschungsprojekte/aktuelle-projekte/nemo.html:

To limit the impact of climate change, it is an obligation for all societies to properly and fully exploit the renewable energy resources at their disposal. In this context, offshore wind energy has great potential to mitigate climate change and – in view of our current geo-political situation now with even higher urgency – can provide wider benefits such as a secure energy supply, a contribution to social and economic development and reducing negative impacts on the environment and health. Meeting these targets while still satisfying the global demand for energy services necessitates further investigation and poses a significant challenge to the scientific community.

In contrast with conventional energies based on fossil fuels, the exploitation of wind energy is strongly affected by the short-term variability of its “fuel”, i.e., the wind. The knowledge of the mean wind resource at a site is decisive for a wind project to be economically feasible over the lifetime of the project. Whilst the mean wind characteristics (e.g., wind speed and direction distributions) are relatively simple to measure, a lack of confidence in the characterization of wind fluctuations, i.e., turbulence, has subsequently resulted in high levels of conservativeness being employed by wind turbine designers.

In short, the assessment of turbulence characteristics as well as its extremes is highly important for an optimal planning and design of wind energy projects. In particular, for the application in offshore wind, essential knowledge gaps exist which are to be approached and closed through the project “NEMO”. The Fraunhofer Institute for Wind Energy Systems (IWES) and France Energies Marines (FEM) collaborate to develop experimental and numerical methods addressing this major challenge for the offshore wind industry. Developers and operators of offshore wind farms as well as wind turbine manufacturers will benefit from the results of the collaboration through the provision of methods for an improved site assessment which will improve the survivability, reliability and performance of wind farms, eventually enabling considerably more profitable wind projects and lower investment costs due to optimized designs.