Feasibility study of low voltage DC distribution system for residential buildings in Bangladesh and hybrid home appliance design for tropical climate

This paper describes a process to make the residential buildings more energy efficient. Three low voltage direct current (DC) distribution systems of different voltage levels are compared with the existing alternating current (AC) system in Bangladesh. Losses in the cable, internal losses of the devices, energy consumption cost, efficiency of the converters and initial cost for new wiring are the factors which have been assessed to obtain the best system. Through the analysis it is found that 48V DC system with optimized cable area is the most economical system among the others as it saves 1,36,859.2 BDT within a life time of 20 years. Besides, a hybrid appliance is prototyped consisting of air-cooler, refrigerator and electric stove altogether for higher efficiency. The wasted heat energies from the cooling devices are stored in a thermal storage by thermoelectric modules and used later for heating purposes for the better overall efficiency.