OBTAINING OPTIMAL CONNECTION COMBINATIONS FOR THERMOELECTRIC COOLER (TEC) DEVICES USED FOR ELECTRICITY GENERATION FROM PHOTOVOLTAIC (PV) PANEL WASTE HEAT

Abstract

The photovoltaic (PV) system with thermoelectric generators (TEG), in which the PV system is cooled by converting part of its waste heat into electricity using the Seebeck effect, is gaining ground. Thermoelectric coolers (TECs), which are Peltier modules, can operate as generators when a temperature gradient is applied. In this research, TECs were used because of their low cost and dual functionality. A water cooling system for the TECs' cold sides was developed. A total of nine (9) TECs were used. Four (4) possible connections were made, consisting of various series-parallel combinations to measure the currents and voltages. These were observed and compared with the temperature differentials. The hot sides of the TECs were glued to the back of the PV panel. Data were collected for 4 days. The four (4) electrical connections of the nine (9) TECs glued to the back of the PV panel were tested for 1 day. The following parameters were measured for PV-TEC: load voltages (V_L), load currents (I_L), Temperatures of the TEC hot and cold sides (TH and TC), and time (t). The output power (P_o) and temperature difference (∆T=T_H-T_C) were calculated. The highest TEC output power was P_o=269.875mW at temperature difference ∆T=23.40^oC. Its connection configuration was three sets of 2TECs connected in series, then connected in parallel, and all in series with 3 other TECs. It shows that P_o is directly proportional to ∆T. It is recommended that the number of TECs and the PV panel size be increased.