Document Type



Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence

Publication Details

linked to SDAR article, " Journal of Sustainable Engineering Design: Vol. 1: Iss. 3, Article 4. Available at:



Generic Wind Energy Estimation Model incorporating Turbulence Intensity.


Manufacturer specific wind turbine characteristic

Mean wind speed at a specific height

Site conditions in terms of TI and Surface Roughness


This model has been designed as an estimation tool for estimating the wind power yield of a custom turbine for an idealised set of site conditions for a given year.

While the assumptions that are made in this estimation tool are mathematically plausible they should not in any way be interpreted as an alternative to a real world site assessment.

A list of assumptions to which the model is based are listed below for clarity.


It is assumed that the following holds true in the mathematical model (however this may not be the case in a real world scenario).

  1. That the overall annual wind speed Probability Distribution Function based on 10 minute sampling bins is in keeping with that of a Rayleigh distribution of similar mean wind speed.
  2. That the site has an associated Turbulence Intensity that is indicative of all wind speeds.
  3. That all wind speeds are considered as being longitudinal in nature (i.e. always flowing directly into the hub). For more information see IEC 61400)
  4. That the turbine has an exceptionally high response rate (i.e. A zero inertia model with no time content)
  5. That within a 10 minute sampling period a Gaussian (Bell Curve) Probability Distribution Function of similar mean and Standard Deviation represents the spread of wind speeds.
  6. That the wind turbine hub is always positioned within or above the canopy layer z*
  7. That the turbine is in stalled in a neutral climate.
  8. That the turbine power characteristic provided by the user is indicative of a 0% turbulent environment.