An effective multi-source energy harvester for low power applications

Small autonomous embedded systems powered by means of energy harvesting techniques, have gained momentum in industry and research. This paper presents a simple, yet effective and complete energy harvesting solution which permits the exploitation of an arbitrary number of ambient energy sources. The proposed modular architecture collects energy from each of the connected harvesting subsystems in a concurrent and independent way. The possibility of connecting a lithium-ion or nickel-metal hydride rechargeable battery protects the system against long periods of ambient energy shortage and improves its overall dependability. The simple, fully analogue design of the power management and battery monitoring circuits minimizes the component count and the parasitic consumption of the harvester. The numerical simulation of the system behavior allows an in-depth analysis of its operation under different environmental conditions and validates the effectiveness of the design.