Optimal sizing and economic analysis of self-consumed solar PV system for a fully DC residential house

The fluctuation offuel prices has become concern to the Malaysian since it will influence the electricity tariff. The objective of this paper is to design a self-consumed DC power system for a residential house from renewable energy resource which is solar PV that will be independent from the utility grid. The methodology proposed are configuring daily load demand, sizing PV array, battery bank and lastly simulation and optimization of the system through HOMER software. Based on HOMER simulation, the optimum PV array size is 3.5 kW while the 48 V battery bank needs 32 units of 12 V batteries, which is designated for 3 days of autonomy. The system could meet 100% of load demand throughout the year with 37.08 % of excess energy. The consumers can benefit of reducing utility electricity bills up to 2,434 kWh annually and to the environmental aspect, will avoid 1. 7 tons of CO2 releases into the atmosphere.