The two-parameter Weibull distribution has garnered much attention in the assessment of wind
energy potential. The estimation of the shape and scale parameters of the distribution has brought
forth a successful tool for the wind energy industry. However, it may be inappropriate to use the
two-parameter Weibull distribution to assess energy at every location, especially at sites where
low wind speeds are frequent, such as the Equatorial region. In this work, a robust technique in
wind resource assessment using a Bayesian approach for estimating Weibull parameters is first
proposed. Secondly, the wind resource assessment techniques using a two-parameter Weibull
distribution and a three-parameter Weibull distribution which is a generalized form of twoparameter
Weibull distribution are compared. Simulation studies confirm that the Bayesian
approach seems a more robust technique for accurate estimation of Weibull parameters. The
research is conducted using data from seven sites in Equatorial region from 1o N of Equator to 19o
South of Equator. Results reveal that a three-parameter Weibull distribution with non-zero shift
parameter is a better fit for wind data having a higher percentage of low wind speeds (0-1 m/s) and
low skewness. However, wind data with a smaller percentage of low wind speeds and high
skewness showed better results with a two-parameter distribution that is a special case of threeparameter
Weibull distribution with zero shift parameter. The results also demonstrate that the
proposed Bayesian approach and application of a three-parameter Weibull distribution are
extremely useful in accurate estimate of wind power and annual energy production.