Assessing the effect of design parameters on optimal size of isolated PV systems for residential utilizations

This paper investigates the effect of varying different operating and design parameters on the sizing and economics of standalone PV systems for residential utilization. Each subsystem is sized using simplified mathematical expressions considering the effecting parameters as input variables. Thus, the sizing and economics of the entire system can be investigated in a generic form. The cost of each system component is analyzed based on international prices and aggregated to obtain the overall cost of energy (COE). The study is based on a 5 kWh/day residential load. A peak load power of 1300W is considered when sizing the inverter capacity. Among the design factors, the battery bank voltage, charge controller type, the solar irradiation and the depth of discharge (DOD) are investigated to examine their effect on the system economy. The analysis results show that the COE relies heavily on both the size and the selected design voltage of the battery bank, which in turn depend on the storage hours, charger size, the (DOD) value and solar irradiation.