Characterization of wind turbine siting parameters in complex terrain using remote sensing

Characterization of wind turbine siting parameters in complex terrain using remote sensing

This project aims to contribute with better wind turbine siting using the WindScanner technology

Motivation and Research Questions

Current wind turbines can reach more than 120 m of hub height and five acres of swept area, hence inhibiting the exclusive usage of tall met masts. Additionally, when considering complex terrains, wind resource characterization has to account for highly site-dependent distortion effects. To achieve a detailed wind resource mapping, accurate local data has to be available to calibrate current resource assessment methodologies. The present-day solution of commercial Doppler laser remote sensing technology, called Lidars, has to rely on the necessity to average the wind over a large volume, which presumes a flat terrain with a horizontally homogeneous flow.

For this reason, the current IEC standard only considers remote sensing applications in flat terrain, allowing only traditional anemometry on complex sites. The WindScanner system aims to overcome such limitations with the usage of two or more synchronized intersecting lasers aiming at the same point. Meso and microscale model validation for resource assessment using WindScanner technology is a topic to be further explored, where a measurement campaign with a high data recovery rate is expected. The present project aims to select a site with highly complex terrain and particular meteorological features to address the following research questions:

  • Which meso and microscale flow patterns are truly relevant for wind turbine siting in complex terrain?
  • How to reduce the uncertainty of wind turbine siting using multi-lidar measurements?
  • How to couple in-situ measurements with a numerical model chain (meso to microscale) for model evaluation and uncertainty quantification?
Project Description

This project aims to design and conduct a full-scale measurement campaign, using WindScanner technology, to provide a valuable dataset for numerical model evaluation. The verification and validation (V&V) process require the characterization of flow patterns and siting parameters with high temporal resolution over a large complex site. All the experience from previous experiments with multi-lidar measurements is going to be applied in the scientific planning of this experiment to acquire the most valuable dataset. Multi-lidar campaigns in complex terrain using WindScanner have already being done and demonstrated these system's capabilities.

The field measurement campaign is part of the New European Wind Atlas (NEWA) Project, where the WindScanner was deployed at several sites across Europe and serve as an input from numerical models, to be part of a new methodology for resource assessment and wind farm planning. The last scheduled field campaign is the Alaiz experiment, located in complex terrain where a wind turbine testing site in Spain.

This project aims to conduct the Alaiz experiment thoroughly, commissioning five WindScanner systems along with several 80 m met masts, commercial lidars, and surface flux stations. The complexity of the site, given by substantial elevation changes and influence of large-scale terrain features, such as the Pyrenees, is a unique feature of this experiment. Apart from the challenging aspects of the site, new data processing techniques are required for data interpretation and model evaluation.

Perspectives

The database from met masts, conically scanning lidars and WindScanners gives the possibility to characterize highly complex terrain flow patterns and develop a new approach to match in situ measurements and numerical models, aiming to reduce the uncertainties in wind resource assessment.