Estimating Weibull Parameters for Wind Energy Applications using Seven Numerical Methods: Case studies of three costal sites in West Africa

Agbassou Guenoukpati,Kossi Napo,Adekunlé Akim Salami,Mawugno Koffi Kodjo

doi:10.14710/ijred.9.2.217-226

Agbassou Guenoukpati, Kossi Napo + Show 2 more

Open Access

https://doi.org/10.14710/ijred.9.2.217-226

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Abstract

In this study, the effectiveness of seven numerical methods is evaluated to determine the shape (K) and scale (C) parameters of Weibull distribution function for the purpose of calculating the wind speed characteristics and wind power density. The selected methods are graphical method (GPM), empirical method of Justus (EMJ), empirical method of Lysen (EML), energy pattern factor method (EPFM), maximum likelihood method (MLM) moment method (MOM) and the proposed. Hybrid method (HM) derived from EPFM and EMJ. The purpose is to identify the most appropriate method for computing the mean wind speed, wind speed standard deviation and wind power density for different costal locations in West Africa. Three costal sites (Lomé, Accra and Cotonou) are selected. The input data was collected, from January 2004 to December 2015 for Lomé site, from January 2009 to December 2015 for Accra site and from January 2009 to December 2012 for Cotonou. The results indicate that the precision of the computed mean wind speed, wind speed standard deviation and wind power density values change when different parameters estimation methods are used. Five of them which are EMJ, EML, EPF, MOM, ML, and HM method present very good accuracy while GPM shows weak ability for all three sites.

Highlights

Nowadays, West Africa faces the challenge of generating more electricity to meet existing and future demand in a sustainable way (Brew-Hammond and Kemausuor 2009; Deichmann et al 2011)
It is observed that six methods (MLM, EPF, empirical method of Justus (EMJ), empirical method of Lysen (EML) moment method (MOM) and Hybrid method (HM)), expected graphical method (GPM) present a better curve fit with the histogram of the wind speed on the three sites
The purpose of this article is to determine a suitable method for estimating Weibull parameters for wind energy applications on three costal sites in West Africa

Summary

Introduction

West Africa faces the challenge of generating more electricity to meet existing and future demand in a sustainable way (Brew-Hammond and Kemausuor 2009; Deichmann et al 2011). J. M., & Smulders 1979) suggested the MLM (maximum likelihood method) for the estimation of the parameters of Weibull wind speed distribution. Seguro and Lambert (Seguro and Lambert 2000) compared the commonly-used (MLM), (GPM) and the proposed MMLM (modified maximum likelihood method). As a result, they concluded that MLM performs better than GPM. Dorvlo (Dorvlo 2002) estimated the Weibull parameters used to model wind speeds in Oman using three methods, the Chi-square method, moment method (MOM) and GPM. (2020) Estimating Weibull Parameters for Wind Energy Applications Using Seven Numerical Methods: Case studies of Three Coastal Sites in West Africa.

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