Improved wind resource modeling using bimodal Weibull distribution

Despite the common norm of modeling wind regimes using two-parameter Weibull distribution (2WD), this probability density function (PDF) is not suitable for sites of calm wind regime. Furthermore, 2WD PDF lacks bimodality and exhibits a quasi-flat shape, which are phenomena seen occasionally in some sites. In this paper, the application of bimodal Weibull distribution (BWD) is proposed as a more comprehensive alternative to the conventional 2WD. A comparative analysis of BWD with 2WD, five-parameter Weibull and Weibull distribution, and three-parameter generalized extreme value distribution, across 32 sites spanning all five continents, reveals moderate to substantial improvements in root mean square error, χ2 statistic, and R2. In addition, the paper demonstrates and explores distinct attributes of BWD, such as bimodality, quasi-flat shapes, flat-start, and others.