Field reliability analysis methods for photovoltaic inverters

Given the increasing importance of solar power and the efforts to optimize large power plants, the effect of subsystems on levelized cost of energy (LCOE) is being examined in increasing detail. For the photovoltaic (PV) inverter, which is one of the most complicated elements in a PV system, reliability has been an important issue. There are many ways to measure and report reliability of electrical equipment. This paper reviews some of these metrics and discusses their application to PV inverters. An example calculation of inverter downtime and availability is also presented for a sample population of 30kW commercial-class inverters.