Long Term Output Deterioration of Grid-Ttied PV Systems
Abstract
This is a report on the deterioration of the output of grid-tied solar electric systems over time. Commercial and residential systems are included. The capacities of the solar arrays range from 1.25 kW dc to 455 kW dc. Initially, 25 systems were in the study, 19 systems remain. The monthly output of each system has been recorded since the systems were installed. The most recently installed system is 10 years old; the oldest is 15 years old. All systems in the study are located in the northeastern US. The recorded output includes that of the inverter and the array. String-inverters are used exclusively. Excel’s Trendline function is used to project system output from each system out to 20 years, based on recorded output. Causes for system output deterioration are given. Four different types of solar electric collector modules are included. Two studies of historical system output are referenced.
Keywords
Solar electric collectors, Grid-tied solar systems, Long term deterioration of solar electric systems, Fixed-mount solar electric systems, Sun-tracking solar electric systems, String inverters, Intermin report.]