The effect of inverter efficiency on stand-alone residential PV system sizing

Renewable energy resources have been widely adopted in the world due to environmental concerns, energy shortage, and decreasing cost of system components. Among these renewable energy sources, solar energy generation has attracted significant interest due to its easy implementation. Solar energy is especially good for residential buildings that are far from existing electrical grid. In such a solar powered stand-alone residential system, a backup source such as battery/supercapacitor is required for uninterrupted energy. The DC energy from solar panels is converted to AC energy thorough a power conditioning system. In this study, the effect of inverter efficiency on the backup size is analyzed. It is shown that for a reliable and correct sizing, the inverter efficiency that varies with loading conditions must be taken into account for stand-alone house where the demand changes within a wide range over a day.