Performance evaluation of solar still integrated with thermoelectric heat pump system

Abstract

This research presents a method for improving a conventional solar still to produce potable water during adverse conditions where there is low or no solar radiation. Summer and winter conditions in the Western Cape province of South Africa were considered. A comparative experimental study was conducted between a conventional solar still and the developed solar still. The developed solar still incorporated a photovoltaic powered thermoelectric heat pump. The purpose of the thermoelectric (TE) heat pump was to accelerate convection inside the developed solar still assembly. The coefficient of performance (COP) of the thermoelectric heat pump installed in the developed solar still ranged from 0.4 to 1.9 at an input current of 5 A. The results indicated that the developed solar still was able to produce 2300 mL per day of drinkable water during a good day in the winter, but the conventional solar still was only able to produce 650 mL per day. The developed solar still produced 2180 mL per day, whereas the ordinary solar still produced 1050 mL per day, during a mild summer day. The developed still had an accumulated water production of 1180 mL during a night with mild temperatures. This significant improvement in yield of the developed solar still system is due to the change in temperature difference between the glazing and the water surface within the developed solar still. This is a significant contribution to the technology of solar water purification.