Study of wind variability in the northern coast of the State of Rio de Janeiro for Aeolian-electric generation

Abstract

This work describes wind variability in the northern coast of the State of Rio de Janeiro. Data of the speed and direction of the wind were used from two meteorological stations: one at the Rural Federal University of Rio de Janeiro, with an anemometer at 2 meters of height and 31 years of recordings; and a second station at the Petrobrás Heliport in Farol de São Thomé, operated by Infraero with 6 years of daily recordings, from 2002 to 2007 with an anemometer at 10 meters of height. The data observed at these stations were compared to the data of the reanalysis given by the National Centers for Environmental Prediction (NCEP) and by the “National Center for Atmospheric Research “ (NCAR). The relevance of a study for the determination ofwind variability for aeolian-electric generation purposes is due to the fact that this primary source of energy presents a variable regime, unlike other conventional sources such as water or thermo gas, and because it is crucial in the total energy generated during a certain period of time. This study on wind variability was carried through statistical analysis of historical series of wind data collected at the Baixada Campista, aiming at obtaining information on the medium wind speed and direction regime along the days and months of the year, and predicting the speed occurrence probability using Weibull distribution. Based on the mentioned regime, one can predict the total energy produced by certain aero-generators with different heights and applications. This study has produced information on the aeolian potential of the area, which allows the implementation of small-scale aeolian initiatives for rural electrification in isolated communities, or large-scale ones for aeolian production parks and electric power commercialization. In the Baixada Campista area, the survey found an average of aeolian potential density (DPV) of 207 W/m2 at the height of 10m and 513 W/m2 at the height of 50m, the wind direction being predominantly northeast (NE), with a 38% of frequency rate. The medium wind speed found at the height of 10m was 5,73 m/s, and 7,73 m/s at the height of 50m. The found wind regime presented a Weibull form factor (K) of 2,11 for the period 2002-2007. The quarterly OND period presented better regularity in the wind regime, with K = 2,27.