Wind modelling based on wind input data conditions using Weibull distribution

Abstract

Weibull distribution can be used to model the wind speed distribution at a particular site and hence, it can help in wind resource assessment (WRA) of a site. By calculating the shape (k) and scale (c) parameters for Weibull distribution, the wind speed frequency curve for a site can be made. Once this wind speed distribution for site is determined, it can be convolved with the power curve for a wind turbine and the annual energy output from the site can be determined. This paper presents how the Weibull distribution is used to determine the wind speed distribution for Vadravadra site in Gau Island of Fiji and how closely the annual energy output from the modelled wind speed distribution matches with the annual energy output using the actual wind speed distribution. It also presents how k is related to the turbulence intensity for a site; how the c is related to the annual mean wind speed and how a formula for estimating c is derived at a new height.