Road energy harvester designed as a macro-power source using the piezoelectric effect

While energy harvesting is commonly used for micro-power sources, it could be applied in macro-power sources using a large-scale harvester in a spacious area. We designed and optimized an energy harvester for a busy roadway using piezoelectric cantilever beams. Using the road vibrational frequency under vehicle speeds of 60-80 km/h, we tuned the natural frequency of the beams by attaching a tip mass. Considering the typical vehicle wheel width and the depth of pavement, the designed energy harvester with a volume of 30 x 30 x 10 cm(3) contained 48 piezoelectric beams. To optimize the harvester circuit, we rectified the output current from each piezoelectric beam and connected the beams in parallel to avoid phase difference interruptions. Finally, we conducted impedance matching to maximize the output power. As a result, we realized an output power of 736 mu W with a power density of 8.19 mW/m(2). (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.This work was supported by the Energy Efficiency & Resources Core Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20142020103970)