Weibull Parameters Estimation Methods for Analysis of Hydro - Wind Complementarity in Northeast Brazil

Abstract

This paper presents a study of the prediction of wind energy production by using the bi-parametric Weibull distribution. Five different methods were studied to obtain the distribution parameters for the State of Pernambuco. Analyzes were performed for five historical series of wind speed located in municipalities of the State of Pernambuco, from 2005 to 2015, measured at 10 meters high. For performance analysis, correlation coefficient, root mean square error, confidence interval and significance level of 5% were used, which relate the data from the historical wind series to the values ​​resulting from each method. Considering the values ​​of k (form factor) and c (annual scaling factor), it is estimated that the average probability of occurrence of values ​​greater than 3.5 m/s is greater than 90% for the five municipalities, considering wind speed at 120 m. Analyzes of hydro-wind complementarity were carried out, and it was verified that wind energy production in the region should represent a saving of about 9.55% in the average Sobradinho inflow, which is used as a source in hydroelectric generation. Energy Pattern (PE) method presents significant results compared to the metrics of the other four methods, and it has been shown that it can be used as a reference for the generation of wind energy.