Low-Area PV Cells Under Indoor Artificial Lighting: A Comparative Study

In the field of energy harvesting for autonomous sensors located indoors, this article carries out an experimental evaluation of different technologies of photovoltaic (PV) modules under different types of indoor artificial lighting. The optical energy available indoors is much lower than outdoors and, in addition, the area of the PV module for a tiny sensor node is expected to be small (i.e., around 10 cm2). At such conditions, an appropriate selection of the PV technology for a given type of indoor artificial lighting is crucial, otherwise the energetic survival of the sensor node could not be guaranteed. Accordingly, this article evaluates 12 different types of PV module under four different types of artificial lighting. Overall, 48 different combinations (or module-light pairs) are tested and compared in terms of power density, efficiency, fill factor, and linearity with the aim of determining optimal pairs for indoor applications.