Abstract
Energy efficient approach of providing refrigeration needs is of one of the challenge facing most developing countries. The objective of this work is to study the effect of ambient temperature on the performance of 12 V and 24 V photovoltaic DC refrigerator with/without loading operated at 25 degrees C and 35 degrees C. Experiments were carried out at different thermostat setting of the refrigerator. The daily compressor run time and energy consumption of the refrigerator were calculated at various operating conditions. The monthly and annual consumptions of the refrigerator were also carried out. The minimum and maximum increase in compressor run time per day for every degree increased (in average from 25 to 35 degrees C) in ambient temperature is investigated and f degrees und to be 0.216 h/degrees C and 0.912 h/degrees C for 12 V system. While for 24 V these values rises to 0.317 h/degrees C and 1.079 h/degrees C, for different thermostat settings. Also the increase in energy consumption per day for every increased in loading for 12 V and 24 V operation were recorded as 76.9 Wh/L and 91.7 Wh/L respectively. The comparison results showed that 12 V operations of DC refrigerator can be much more efficient than 24 V operations especially at higher ambient temperature with an average of energy saving of 81.28 kWh/year.