Hybrid Thermoelectric Generation Characterization Platform

The growing adoption of thermoelectric generators (TEGs) and solar thermoelectric generators (STEGs) for energy harvesting has increased the demand for flexible experimental platforms capable of controlled electrothermal testing under diverse thermal excitation conditions. This paper presents the development and experimental demonstration of a hybrid thermoelectric experimental platform for controlled electrothermal investigations, integrating ceramic positive temperature coefficient (PTC) heating, controlled halogen-based optical irradiation, multistage thermoelectric cooling with active liquid heat rejection, embedded PID-based thermal regulation, and synchronized thermal and electrical data acquisition. An ESP32-WROOM-32-based supervisory system provides autonomous control, remote monitoring, and the independent regulation of the heating and cooling subsystems. Under the investigated conditions, cold-side temperatures approached −40 °C, while hot-side temperatures approached 200 °C under resistive excitation and approximately 170 °C under maximum optical excitation; sustained controlled optical operation was limited to approximately 150 °C. Four independently calibrated NTC temperature channels exhibited a maximum observed calibration deviation within ±1% over the evaluated ranges, representing calibration performance rather than the combined uncertainty of the complete measurement system. Timestamp-based alignment of thermal and electrical measurements resulted in a residual digital synchronization skew below 50 ms, characterizing the temporal alignment of the recorded data streams rather than the physical response time of the temperature sensors. In a transient TEG experiment, the platform produced a maximum externally measured temperature difference of approximately 161.74 K and a transient open-circuit voltage peak of 1.7818 V, demonstrating temporally aligned observation of thermal and electrical responses during controlled thermal conditioning and passive relaxation. These quantities characterize the transient system-level response under the imposed experimental boundary conditions rather than a direct determination of intrinsic TEG properties. Overall, the results demonstrate the coordinated operation of hybrid thermal excitation, multistage cooling, embedded control, and synchronized electrothermal acquisition within a single reconfigurable experimental infrastructure for TEG- and STEG-oriented investigations.