In wind energy projects, accurate wind measurement is the foundation for estimating future energy production.
One of the factors that most strongly influences measurement uncertainty is the height of the meteorological tower used during the campaign.
The importance of measuring at hub height
Modern wind turbines reach increasingly higher hub heights — 120, 140, or even over 160 meters.
Measuring wind at significantly lower heights increases uncertainty, as it requires extrapolating data using models that may introduce errors.
The closer the measurement is to the actual rotor height, the lower the uncertainty in resource assessment.
Factors that increase uncertainty
- Terrain complexity: in mountainous areas or locations with variable surface roughness, differences between low and high measurements are more pronounced.
- Vertical wind gradient: wind speed profiles change with height, especially in the lower layers of the atmosphere.
- Atmospheric conditions: phenomena such as thermal stratification or turbulence can make extrapolation from lower heights unrepresentative.
Common solutions in measurement campaigns
- Taller towers: installing guyed or self-supporting towers that reach as close as possible to the turbine’s hub height.
- Combined use of LiDAR: this technology complements tower measurements and captures vertical wind profiles up to several hundred meters.
- Scheduled maintenance: ensuring sensors and equipment operate optimally throughout the campaign to avoid adding additional uncertainty.
Impact on resource assessment
Uncertainty in wind measurement has a direct impact on project financing:
Higher uncertainty → higher risk → higher financing costs.
Reduced uncertainty → greater confidence in the resource → more profitable and competitive projects.
In summary, selecting the right measurement tower and reaching the greatest possible height is key to obtaining reliable data, reducing uncertainty, and improving the bankability of wind energy projects.