I. Introduction
The U.S. Department of Energy estimates the photovoltaic (PV) penetration in the U.S. power market to be upward of 18% by 2050, with a $1/watt price point. As the price of PV modules decreases, the price of inverters becomes more important. Inverters now constitute 8%-12% of the total PV lifetime cost [1]. One key price driver of the inverter components is inverter reliability. PV modules are offered up to 30-year warranties. In contrast, typical warranties on inverters last only 5–10 years. Even with the most optimistic view of inverter lifetime, it will be essential to replace or repair an inverter multiple times during the lifetime of a PV module [2]. Further, field data from PV power plant operators demonstrate that power electronics converters contribute the most to operation-and-maintenance events, which are responsible for between 43% and 70% of the service calls [3]. This leads to increased maintenance costs, lost energy production, and, finally, higher levelized cost of energy. Consequently, it is critical to have a generic tool from a third party for PV inverter reliability assessment.