Power Factors 2022 PV System Efficiency Benchmarks

This report presents benchmark analysis of inverter DC to AC conversion efficiency and AC side collection system efficiency characterized from field measurements in Power Factors database. It represents an update and extension to our 2021 study [10] with similar objectives which aimed to benchmark inverter efficiency across multiple dimensions (time, age, manufacturer, model), validate manufacturer specifications and inform energy modelers tasked with predicting inverter performance from manufacturer specifications. Major updates include incorporating additional field measurements from more devices over a longer period of time (including 2021 data), summarizing results of AC side collection system efficiency, updating methodology to use the Sandia inverter model [8] to characterize inverter efficiency and some additional data validation quantifying the impact of measurement bias. It was found that the majority of the most common inverter models perform within 1.0% of specifications, with a mean across all inverters of 97.5%. Additional analysis of AC side collection efficiency indicates that these losses are negligible with a mean of 99.5%.