A multi-year thermoelectric energy harvesting project for first-year engineering and technology students

Energy harvesting for continuously powering sensor networks is an emerging technology with tremendous potential. This paper is a report on progress made with involving first-year engineering and engineering technology students with thermoelectric energy harvesting research and prototype development that has occurred over several years. Each year, the student group built upon the work of the previous year's group. Expectations for each team were kept realistic such that the goals were attainable. However, each group was required to present their work at a regional undergraduate research conference. During the first year of the project, thermoelectric generator (TEG) devices were characterized and tested. The students designed and constructed test fixtures for the TEG and conducted performance tests. Mathematical models were developed and compared with actual TEG performance. During the second year, another group of first-year students designed and constructed circuitry to boost the relatively small TEG output voltage to a level more useful for powering conventional (3.3V or 5V) electronic devices. The boosted output voltage was used to power all of the circuitry thus a self-sustaining system was produced. Sensors and circuits were added to measure the TEG system temperatures and transmit them to a computer for display. The third year's group identified a hot water pipe within the engineering building that could serve as a heat source from which a TEG could be powered. A laboratory mockup of the water pipe heat source was constructed such that it could be tested prior to actual installation. The group designed and fabricated a pipe-to-TEG heat exchanger and custom TEGto- air heat sink for the cool side of the device. The performance of the system was tested using hot water input temperatures that will be experienced in the actual installation. This paper presents details of each group's work as well as observations of student motivation in performing undergraduate research.