Thermoelectric Performance Optimization of Stand-alone Roadway-embedded Sensing Module
The purpose of the research is to optimize the thermoelectric performance of a stand-alone, roadway-embedded, sensing module and determine practical energy conversion rates. Thermoelectric generators (TEG) were incorporated into a piezoelectric (e.g., PZT) energy harvesting module. A thermal conduit was designed and validated which permits module compression and PZT operation, without transferring force to the TEGs. A prototype module was embedded in asphalt and used to gather one-minute resolution temperature gradient data on sunny days in December and in July (in San Antonio, Texas). The module was moved to a laboratory setting, and a Model Predictive Controller (MPC) was designed based on the module's thermal transient response. The MPC constructed was used to reliably reproduce the recorded July and December temperature regimens. Several configurations of TEG electrical and DC-DC booster connections were compared under MPC-controlled temperature conditions. A 120 mV-threshold booster (ELC-BVB120) with four TEGs (TXL-287-03Z) in a 2-series-by-2-parallel configuration yielded the best December day energy conversion (34 J). However, the ELC-BVB120 booster with the four TEGs (TXL-287-03Z) in a 4-parallel configuration yielded the best July day energy conversion (164 J). With year-round temperature information for a given region, the TEG modules could be optimized to provide complementary and sustained energy conversion at specific locations.