Systems, methods and tools for estimating pv module and array power loss attributable to partial shading or soiling of a pv module and array

Abstract

Arrays of photovoltaic modules produce power as a result of incident solar radiation. The amount of radiation reaching a solar cell can be decreased due to light-blocking matter adhering to the module surface. The light-blocking or soiling matter can be snow, dirt, or other particulates such as pollen or excrement, and can be detected on the module surface using visible light photography. We have developed an automated image processing routine to estimate the power loss on a photovoltaic array due to partial surface shading, soiling or coverage from time-series visible light photographs. This tool can inform the design of PV systems optimized for particular operating environments, resulting in more efficient PV systems, can be used to inform the development of new technologies, such as anti-soiling coatings, and can help validate the accuracy of PV performance models in locations that see high rates of soiling.