Shading position effects on photovoltaic panel output power

Abstract

The application of photovoltaic systems in urban environments is affected by partial shading, which causes decreasing converted power. The relationship between the position and the number of shaded modules versus the energy captured by a photovoltaic panel under degraded conditions has not been explored. This paper shows a novel approach that identifies and establishes the relationship and relevant conditions to the partial shading of photovoltaic module connections. The methodology consists of the analytical examination of the electrical parameters of a photovoltaic cell and connections of these cells under shaded conditions. In this work, a computational analysis of the photovoltaic cell, module, and panel under shading conditions using electric modeling for the solar cells is proposed. There are experimental results confirming the analytical and computational methodology carried out with identification of the relationship between the shading position over the photovoltaic panel and its generated power. It was verified that the magnitude of the negative effects caused by shading, that is, loss in output power, is directly and mainly related to the position of shaded modules in the shaded panel. The number of shaded modules causes, on a minority basis, a decrease on the output power.