ICT2014 Abstracts

Solar thermoelectric generators (STEG) have drawn interest as an alternative solution to PV cells for sustainable power generation at the residential scale, with reported theoretical efficiencies up to 30%.  Most previous studies assume that the cold side of the modules is fixed at ambient temperature and maximum power occurs when load resistance is matched with internal impedance.  Fixed cold side temperatures require powerful active cooling that may consume more power than the amount of power generation from a module, which questioned practicality of the STEG approaches.  Moreover, source temperature changes with amount of power extraction with a module, which prevents the usage of traditional load matching conditions and resulted in discrepancy between theoretical and experimental STEG efficiencies.  If forced cooling is necessary for effective thermoelectric energy conversion, the STEG approach is better suited for a combined heat and power (CHP) system; utilize thermoelectric module as a topping cycle for solar thermal application.  This work explores a solar thermal powered absorption refrigeration and thermoelectric system.  Optimum working conditions (concentration ratio, module geometry, and heat sink dissipation ability) are determined to maximize combined efficiency of heat and power produced by the system.  A prototype was built to validate modeling results and generated 3W of electricity and 120W of heat from a .6 m² area dish.  Experimental results fall within 2.1% of the modeling.