The Effect of Inverter Failures on the Return on Investment of Solar Photovoltaic Systems

Return on investment (ROI) analyses of solar photovoltaic (PV) systems used for residential usage have typically shown that at least 10 to 12 years is needed to break even, with this amount varying based on tax credits and reliability. This paper discusses the challenges with the reliability of current solar photovoltaic systems and the key reliability bottlenecks, with a focus on the ROI. The problem stems primarily from reliability issues of currently available power electronics hardware. This paper's analysis of failure data shows that the short warranties and reliability concerns associated with solar PV inverters reduce the long-term ROI of residential solar PV systems by up to 10%. This paper, therefore, provides key insights for accurate ROI calculations for solar PV investments. Furthermore, methods to improve the reliability of PV inverters, such as selection of capacitors, inverter topology, and incorporating wide-bandgap semiconductor devices, are presented.