Inexpensive Indoor Spot-cell and Spot-light Methods for Angle of Incidence Measurements of PV Modules

Various testing methods have been explored in the past to study the effect of the angle of incidence (AOI) on the short-circuit current (Isc), and hence the power, of a photovoltaic module. In this paper, we are presenting two simple methods for determining the effect of AOI on the short-circuit current, namely the spot-cell method applied on the 1-cell module and the spot-light method applied on the full-size commercial module. The purpose of this work is to design and establish an inexpensive but accurate indoor test setup that can be used by the industry to obtain AOI curves for a cell or a module. This paper provides details on the construction and operation of the test setup. The AOI curves obtained in this work have been compared and validated using the AOI curves obtained as per IEC 61853-2 standard. This paper presents AOI results obtained on crystalline silicon cells and modules with glass superstrates, with and without anti-soiling coatings, and with and without artificially deposited soil layers.