Revisiting the model parameters of an existing system using the Photovoltaic System Analysis Toolbox (PVSAT)

Model parameters that represent a photovoltaic (PV) system as built may not align with the original pro forma pa-rameters estimated and possibly guaranteed a priori in the pro-curement phase of a project. In this paper, the pro forma parame-ters of an existing system are revisited via on-site survey, indoor characterization, analytical modeling, and ex-post performance analysis. Moreover, the Photovoltaic System Analysis Toolbox (PVSAT) is introduced, validated, and used to execute a modern performance guarantee to investigate the impact of varying de-grees of model true-up on production forecasts. Improvements to the original parameter values are achieved, demonstrating how calibration efforts performed even over a brief data collection in-terval can provide valuable insights and mitigate risk.