A solar energy harvesting system for a portable compact LED lamp

This paper presents a solar energy harvesting (EH) system to power a portable compact LED lamp, which can be charged during daytime and used to light during night time. The solar lamp consists of three PV panels, an EH and power management circuit, three NiMH rechargeable batteries, and an LED. A commercial off-the-shelf chip TI BQ25504 is used to prototype the EH and power management circuit for the proposed system. Experimental results show that the proposed PV system can harvest solar energy both in indoor and outdoor environments. The peak net power harvested by the proposed system is about 380 mW on a sunny day, 250 mW on a partly cloudy day, and 30 mW on a cloudy day.