Experimental Water and Air Cooling Performance of a Solar Powered Thermoelectric Module Across a Battery Discharge Cycle
Year: 2026
Type: article
Abstract: This paper reports the design, fabrication and experimental evaluation of a stand alone solar powered thermoelectric cooling unit that chills both water and air, and characterises it through a complete battery discharge cycle, the module being supplied directly from the battery without voltage regulation on the load side. The unit uses a single TEC1 12706 bismuth telluride module supplied from a 12 V, 8 Ah sealed lead acid battery that is charged by a 20 W polycrystalline photovoltaic panel through a 12 V, 5 A charge controller. Waste heat at the hot junction is rejected by an aluminium finned heat sink and a direct current fan, while the cold junction is coupled either to an insulated vessel of water or to a finned radiator placed inside a rectangular duct of cross section 22 cm by 5 cm by 2.5 cm. In the water cooling mode the load was brought from 23.5 degree Celsius to 2.1 degree Celsius in 139 minutes, a reduction of 21.4 kelvin, while the hot face settled near 39 degree Celsius. In the air cooling mode seven runs at different states of battery charge produced outlet air temperature reductions between 3.4 and 12.3 kelvin, with a mean reduction of 7.3 kelvin, accompanied by a mean loss of about 51 percent in air velocity caused by the flow resistance of the finned radiator, a trade off the duct was built to quantify. For a 250 millilitre load the mean cooling capacity was 2.69 watts over the whole run and 6.70 watts over the initial linear regime, giving a peak coefficient of performance of about 0.11. The results show that the cooling rate is governed mainly by the supply voltage and by the effectiveness of hot side heat rejection, and that the cold face temperature falls asymptotically as the temperature difference across the module approaches its limiting value. The system needs no refrigerant, has no moving part other than the fans, and responds within seconds of switching, which suits it to small capacity point of use cooling and heating, to laboratory and research duty requiring a controlled surface temperature, and to service in locations where grid electricity is unreliable.
Authors: T. Haritha, M. T. Naik
Institution: Jawaharlal Nehru Technological University, Hyderabad
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7208750267