Design and investigation of photovoltaic and thermoelectric hybrid power source for wireless sensor networks

Sustainable operation of sensor nodes powered by limited lifetime batteries is a key challenge. Environmental energy harvesting is an attractive technique to forestall this energy crisis of wireless sensor networks. We have developed a kind of self-renewing photovoltaic and thermoelectric hybrid power source for sensor nodes. This kind of hybrid power source is composed of solar cells, thermoelectric generators (TEG) and heat sinks. The solar cells are the main power source for the load as well as the heat source for the TEG. The heat sinks dissipate heat for the cold-side of the TEG. The temperature difference between the hot-side and the cold-side makes the TEG become the additional power source for the load. This paper presents design considerations and results analysis of the hybrid power source. Experimental results demonstrate that the photovoltaic and thermoelectric hybrid power source can replenish energy itself and enables near perpetual operation of the sensor node.