As wind energy projects grow in scale and complexity, accurate and consistent site assessment remains important for reducing uncertainty and supporting investment decisions. Results from the 2025 Measnet Site Assessment Proficiency Test (PT) indicate a high degree of consistency among laboratories applying Measnet standards.
Twelve international ISO 17025-accredited laboratories from the Measnet Site Assessment Expert Group successfully passed the intercomparison.
The PT was an internal exercise restricted to Measnet members in this area of competence, but was conducted under the IECRE framework (O.D. 551-17).
Participants evaluated a complex-terrain wind farm site using the Measnet Evaluation of Site-Specific Wind Conditions, Version 3 procedure for wind resource and site suitability assessment.
A common, standardised dataset was used, comprising one year of meteorological mast measurements and 20 years of long-term reference data. Participants completed the assessment workflow from data filtering through to Annual Energy Production (AEP) estimation.
The PT focused on four technical areas: modelled wind shear across the rotor area, turbulence intensity transferred to hub height, horizontal extrapolation of long-term wind conditions to turbine locations, and AEP after wake losses.
The results showed a high degree of consistency among participants:
- ±1.7% precision for long-term wind conditions at hub height and turbine positions
- ±4.3% precision for AEP after wake losses
- ±3.8% precision for turbulence intensity transferred to hub height
- Wind shear modelling within a ±0.03 exponent tolerance
Measnet plans to expand future proficiency testing rounds to external participants, with the aim of further developing technical expertise and consistency in site assessment.
The Measnet Evaluation of Site-Specific Wind Conditions, Version 3 is available in the Documents section of the Measnet website.
