Analysis of Seasonal Aspects of Nebulosity on the Project of Fixed Photovoltaic Installations at the City of Belém, Brazil

Abstract

By using INMET meteorological data, the Radiasol 2 program and calculations performed to estimate the solar zenith angle, this work aims to estimate the effect of the orientation of fixed photovoltaic panels, taking into account the seasonal aspects of the cloudiness at Belém city, Brazil. At first, the periods of the year of smaller and greater cloudiness are identified. Then, the average angles of solar zenith are estimated for the cloudiest season, for the clearest sky season and for the whole year. Thereafter, the Radiasol 2 program is used to estimate the incident solar energy density on the fixed panels inclined at these estimated zenith angles and during one year. This work intends to estimate and to analyze the impact of the solar panels orientation, considering periods of cloudiness, on the generation of electric energy. The results of solar radiation received at inclined planes show that if the photovoltaic panels are inclined considering the average angle of solar incidence for the least cloudy period of the year, a slight increase is observed in the solar radiation received annually at the panels plane, when compared with the radiation received for the calculated mean zenith angle regarding the cloudiest period.