PRELIMINARY ANALYSIS OF THE DISTRIBUTION OF GLOBAL HORIZONTAL SOLAR RADIATION IN THE CITY OF PORTO ALEGRE - RS

Abstract

Solar energy has shown rapid and sustainable growth in Brazil over the last few years. The drop in costs of solar systems, regulation and government incentives has contributed to the increase of all types of solar energy applications, whether for energy, lighting, heating and other uses. In the same way, there is an increase in the demand for more detailed and qualified data regarding the behavior of solar radiation on the Earth's surface to improve the performance of projects that use this energy as their main source. Only information about the average annual or monthly values of solar energy available on the surface is insufficient for the correct modeling of large-scale systems or systems that use energy storage. This work aims to analyze the behavior of the distribution of horizontal daily global solar radiation in the city of Porto Alegre, Rio Grande do Sul (Latitude -30.05 and Longitude -51.16), through data collected between 2001 and 2014 by the automatic weather station (EMA) of the National Institute of Meteorology (INMET). From the treated, qualified, and analyzed horizontal global solar radiation data, information was obtained on the daily, monthly, seasonal and annual frequency distribution of the horizontal daily global radiation. The annual average value for the daily horizontal global solar radiation was 1533 kWh/m² with a standard deviation of 65.26 kWh/m² and a coefficient of variation equal to 4.25%. The monthly averages integrated from the daily values show maximum values in January (6.23 kWh/m²) and minimum values in June (2.16 kWh/m²).