Optimal energy cost and economic analysis of a residential grid-interactive solar PV system- case of eThekwini municipality in South Africa

The impact of battery storage and grid electricity price on the profitability of the grid-interactive solar PV system is also analyzed. It is shown that the use of battery storage system will have a positive effect on the system profitability only when the FIT is not attractive. For attractive FITs, the use of battery storage will have a negative effect on the profitability of the grid-interactive solar PV system. Simulation results also show that the higher the grid electricity price the higher the profitability of the system.