Impact of Power Converters and Battery Lifetime on Return of Investment of Photovoltaic Systems

The installations of photovoltaic (PV) systems with integrated battery energy storage are strongly dependent on their economic profitability. The return of investment (ROI), which is a metric commonly used to evaluate the cost-effectiveness of PV-battery systems, can be strongly influenced by the replacement cost. Thus, the lifetime of the reliability-critical components, such as power converters and battery, plays an important role and needs to be considered during the full economic evaluation. In this paper, an impact of power converters and battery lifetime on the economic profitability of the PV-battery system is analyzed. A case study considering different PV panel and battery sizes reveals that the ROI can be deviated up to 20%, if the power converters and battery need to be replaced several times during the entire lifetime operation of the PV-battery system. Hence, the lifetime analysis should be included in the economic assessment and reflected with a more realistic component replacement cost during the planning stage of the PV-battery projects.