Statistical Study of Brazilian Solarimetric Measurements and Comparison with Satellite Models for Eventual Use in Feasibility Studies of Photovoltaic Solar Generation

In Brazilian Energy Sector, solar photovoltaic energy is increasing its importance. It presents itself as a promising alternative for supplying national electric demand. In order to develop a photovoltaic system, it is very important to know how solar resource behaves in a given place and its variability during the year. The objective of this study was to obtain data from a given number of solarimetric stations and to compare it with satellite data from the same places, analyzing the differences observed in order to assess its influence in the risks of the decision to construct a photovoltaic generation system. It was concluded that irradiation models presented high correlation coefficients with the typical meteorological year, higher than 0.90 for the less accurate and higher than 0.98 for the more accurate. Student's t test presented probability higher than 97% of the results to correspond to reality. Another conclusion indicates that models with higher correlation coefficient can be used in feasibility studies for decision making, with uncertainties smaller than measurement errors.