Combined AC and DC Energy Harvesting Methods

Much of the work on ambient energy harvesting currently focuses on maximizing the efficiency of the power extraction method or increasing the power output. However, an important goal is still out of reach: to produce sufficient and sustained power for wireless sensor nodes and their associated components. Achieving this goal will significantly impact the fields of structural health monitoring, secure location surveillance and a multitude of other pertinent applications. While many energy harvesters can power these electronics with a constant energy source, most ambient sources for desired wireless sensor networks only provide intermittent energy. One method for increasing the robustness and versatility of energy harvesting systems would utilize multiple energy sources simultaneously. In order to achieve this, the problem of effectively combining multiple energy harvesting sources, specifically an AC and a DC source, is thoroughly explored with the experimental analysis of proposed circuit configurations. Also, a multi-source energy harvesting circuit configuration is proposed.