Monthly Solar Irradiance Variability in Brazilian Climate Zones
Abstract
One of the main barriers to increase the solar energy share is its intermittency. In this work, we propose a methodology to evaluate the monthly variability of the incoming surface global solar irradiance using the effective cloud cover coefficient estimated from satellite imagery data. The Pearson correlation between the monthly variability from the satellite cloud cover and the ground based irradiance data for all sites was up 0.94. The smallest discrepancies happen when analyzing the same timescale (30-minutes). The methodology uses only the visible geostationary imagery, and it was able to well represent the monthly variability with only low discrepancies that may be a topic for future work. The results denoted that the proposed methodology is an interesting alternative to evaluate the solar irradiance variability over large areas with satisfactory accuracy, where no ground data is available.