Study of the Nebulosity Influence in Photovoltaic System Installed in the Green Office of UTFPR

Abstract

Since 2015, the photovoltaic solar energy has had a significant increase of its installed power in Brazil, which has great potential for the generation of electrical energy with the use of photovoltaic systems due to its high irradiation index. However, a problem for the generation of electric energy by the means of photovoltaic systems is the fact that the shadow existence impacts directly the generation, as a result of the reduction of the incident irradiance in the panels. The factors which can cause shadow effect are the external solid bodies and cloudiness, which can have its effect on photovoltaic systems increased by the cloud position in relation to the sun. Thus, this article is a study about the cloudiness influence in a photovoltaic system connected to grid, denominated Green Office of the UTFPR. For that, clearness index analyses (Kt), the daily energy generation and the productivity (YIELD) have been analyzed for some different cloud conditions: clear skies, few clouds, high cloudiness, and considerable rainfall. The results showed the direct relation of the clearness index with the productivity and the electric generation of the panel, whose values were higher in the higher Kt cases.