Mapeamento eólico do estado de Alagoas utilizando ferramentas computacionais e dados observados

Abstract

With the growing energy demand and the opportunity for exploitation of renewable energy (wind energy), this paper performs the mapping of wind potential in Alagoas. This study is based on the use of anemometer measurements between August/2007 to July/2008, as also computational tools: mesoscale atmospheric model (WRF); numerical model of microscale (WAsP®); data from Geographic Information Systems (GIS). The stations with anemometers were geographically distributed in three mesoregions of the State: Backwoods Sertão (Água Branca), Rural Agreste (Girau do Ponciano and Palmeira dos Índios) and Coast Litoral (Feliz Deserto, Maragogi and Roteiro). WRF simulations have validated by time series (daily average, monthly average and diurnal cycles), statistical analysis and Weibull distributions. It was also evaluated using WAsP as a tool for calculating the spatial wind speed in microscale. The input data in WAsP, in addition to the WRF model simulations and the preparation of various maps, were all treated and developed in the ArcGIS® software. The results showed greater efficiency in the WRF simulation of wind speed for sites to the interior of Alagoas, with bias less than 1 m.s-1. These estimates were more accurate during the summer season (bias less than 0.5 m.s-1) and more disparate in winter, with average error of up to 3 m.s-1. For the Coast, these values were overestimated by more than 3 m.s-1, except in Maragogi. The wind direction from WRF was calculated with accuracy in all sites, being dominant in the east coast, east to northeast in Rural, and southeast in Água Branca. The annual wind map for WRF for Alagoas showed areas with good potential energy, the magnitude of the wind varies between 7-9 m.s-1 at 50 meters high. Application of the WAsP in the microscale showed good resemblance to the maps obtained in the Wind Atlas of the State of Alagoas - AEEA. The models achieved satisfactory results, but still need to be improved in some respects.