Economic feasibility and backup capabilities of solar-battery systems for residential customers

The integration of distributed solar-battery systems presents significant opportunities for residential households to reduce electricity costs and enhance backup power during outages, particularly given the increasing criticality of electricity in modern life. However, previous studies on residential energy management have primarily focused on economic bill savings while overlooking backup capabilities. Additionally, existing research on power outages has predominantly considered scheduled blackouts, neglecting the impact of unscheduled outages. This study proposes an energy management model that optimizes energy dispatch while accounting for both economic bill savings and backup functionality during unscheduled power outages. First, statistical parameters derived from real-world Australian data are utilized to simulate power outages. Then, quantitative metrics are introduced to assess electricity bill savings, the economic feasibility of battery investment, and the backup capabilities of solar-battery systems during outages. Furthermore, the effects of outage frequency and different load supply strategies on system performance are examined. The results indicate that battery investment for residential users remains relatively high, however, when the backup value of the solar-battery system is considered, the payback time of the battery investment can be reduced by more than 31%. Photovoltaic (PV) systems can contribute more than 39% to the overall backup performance of solar-battery systems as studied across various scenarios.