Efficient Indoor Solar Panel Energy Harvesting Exploiting the Crest Factor

This paper presents novel insights and a new method for improving indoor light energy harvesting for Internet of Things (IoT) applications using a photovoltaic (PV) panel. The concept is based on enhancing the rectifying performance of the intrinsic diode of the PV panel using a high peak-to-average power ratio (PAPR) light waveform. Improving techniques for rectifying systems are well established in the radiofrequency (RF) community but are applied to a light-based system in this paper. A system model is presented to justify the used method. We prove that only a pulse-width modulation (PWM) signal can enhance the energy harvesting at the PV panel. We designed a light-emitting diode (LED) driver and measured the received power to evaluate our concept. For a constant power of the light source, the PWM waveform achieved a 28.8% improvement of the received power compared to a continuous direct current (DC) light source.