Analysis of Dual Power Supply System for Small Office by using Solar Power and Utility Grid

In this paper, analysis of dual power supply system with PV and utility grid is proposed for an office. The main aim of this research is to reduce the electricity costs financially and to reduce the carbon foot print of an office environment. The proposed system is designed for an office building which is located in Mandalay Region. Based on the average solar radiation and location, the photovoltaic system can produce power about 8.1 kW with battery backup which is supplied for this office. Based on the theoretical calculation, 27 numbers SANDISOLAR 300 W modules are required for this system. The nominal system voltage is 96 V and 8 numbers of batteries are required. The total battery capacity of the battery bank is 1370 Ah. There are three conditions included (1) while grid power is unavailable, necessary loads are supplied by PV system and (2) While PV power is unavailable, all of the loads are supplied by grid. (3) For both grid and PV available condition, loads are divided into two parts and supplied power from this two power sources. This system has two advantages for this office to reduce electricity costs financially and reduce carbon foot print.