IEA Wind Task 32: Wind LiDAR Systems für Wind Energy Deployment (Working period 2019-2021)

LiDAR (‚Light detecting and ranging') systems have been used for wind energy applications for more than a decade and have contributed significantly to a cost reduction in the last few years. Although the degree of maturity of technology has risen to a high level, wind-LiDAR-devices are still not fully accepted in the wind energy industry.

To minimize the existing obstacles, the Task 32 of the IEA Wind has been launched in 2013 (since 2022: Task 52). Since then, Task 32 has been dealing with the possibilities and challenges of the application of LiDAR-systems in Wind energy.

Due to the complex topography of many wind turbine sites, the topics of LiDAR in complex terrain and LiDAR availability at mountainous locations are particularly relevant for Austria. Accordingly, these two topics formed the focus of the Task 32 participation of Energiewerkstatt.

For a wind-LiDAR measurement, data from measuring beams in different directions must be combined to obtain the wind vector. For this so-called reconstruction of the wind speed, a constant and homogeneous flow is assumed. In complex terrain, this assumption is often not met, resulting in measurement uncertainty. In order to quantify this uncertainty and evaluate possible correction methods, a comparative study has been carried out from 2019 to 2022 by a working group led by Energiewerkstatt in the framework of Task 32. Measurement data recorded at Austrian alpine locations served as the basis for this study, the results of which were then published in 2022 in the report "Comparative Exercise on Ground Based Lidar in Complex Terrain".

Another national focus in this term of Task 32 participation by Energiewerkstatt, was a comparative study of LiDAR availability at alpine locations. LiDAR measurements are based on the scattering of laser light at aerosols suspended in the air. In very clean air with little aerosols, the availability of the measurement is therefore often severely limited. To quantify this problem, the availability of wind measurements at alpine and lowland locations over the course of the year has been evaluated.

The results confirmed a large difference in availability, especially in winter time, dropped to about 50% on average at mountainous locations. Since outside of Austria mountain locations at high altitudes are seldom used for wind energy, this issue was not apparent in this from in previous international experience with LiDAR wind measurements.

These results of this analysis have also been published in a report. Another dissemination activity that deserves special mention in this term of Task 32 was a meeting organized together with IG Windkraft, where the results from Task 32 and from the other IEA Wind Tasks with Austrian participation (Tasks 41, 51, and 54), could be presented to the assembled Austrian wind industry.

Publications are available on the German part of the website.

Austria, Canada, China, Denmark, France, Germany, Great Britain, Japan, The Netherlands, Norway, South Korea, United States

Project leader:

Alexander Stökl
Energiewerkstatt
Heiligenstatt 24
A-5211 Friedburg