Energy harvesting photovoltaic system to charge a cell phone in indoor environments

Research advances in materials science improved gradually photovoltaic systems efficiency. However, such systems are limited to work in the presence of sun light, and they also depend on the geographic localization and on the period of the year, usually limited to 6 to 8 hours a day. In order to take maximum advantage of solar panels, it is crucial to use them also in cloudy weather or even at night. Therefore, in this paper, we propose to recycle light energy from artificial light sources to enable the use photovoltaic systems along 24 hours a day. We validate our proposal by means of measurements performed using artificial light in indoor environments. As a practical result, we show that 7 hours recharging in an indoor environments implies in 94.08 % of the overall cell phone battery capacity. Furthermore, we also propose a circuit for charging of a battery of a cell phone.