Implementation of Bimodal Probability Density Function to Estimate the Wind Energy Potential in the Region of the Isthmus of Tehuantepec

In this paper is implemented the bi-modal probability density function to improve the fit of wind speed distributions in the site of La Venta in the region of the Isthmus of Tehuantepec, Oaxaca, Mexico. The site of La Venta is very known by its high wind potential and also because the wind speed distribution looks more like a bimodal probability distribution. Thus, it is very common that classic methods based on unimodal probability functions fails to fit the wind distribution of this site and thus, this leads to uncertainties in the estimation of the annual energy production (AEP). However, the problem with classic methods is that they are considered universally valid by the wind industry. On the other hand, the computation of uncertainties is mandatory to request financing for developing new wind farm projects. To demonstrate the performance of the proposed methodology, the fit of the wind speed distribution with bi-modal probability Weibull function is compared against empirical methods of Justus, moments (MOM) and energy pattern (EPFM); and the iterative methods of least squares (LSM), probability of maximum energy (MLE). Five error criteria are used to determine the method which leads in most accurate fit. The annual energy production (AEP) of the site is estimated for a 5000-kW IEA/15 type wind turbine. Finally, the uncertainties of AEP for the proposed methods are estimated.