Solar Energy Harvesting for Wireless Sensor Networks

The commercially available sensor nodes are battery-driven devices. A number of nodes together constitute a network. As days proceed, the batteries used in the nodes lose their charge and subsequently get isolated from the network. Many energy harvesting schemes have been proposed to alleviate this problem. In this paper, a solar energy based energy harvesting scheme is proposed. This scheme works on the principle of photo-voltaic effect. A recharging circuitry is also designed, that recharges the batteries of the nodes when the charge drops below a threshold level. This leads to strengthening the lifetime of the nodes as well as the network. Compatibility and low power design are the two major salient features of the designed circuitry. The performance of the circuit is also tested with the MICAz hardware.