A Comparative Evaluation of Photovoltaic Electricity Production Assessment Software (PVGIS, PVWatts and RETScreen)

The production and installation of PV systems is now one of the world's fastest growing industries. This paper presents the primary differences in the usage and results of three major free software packages, Photovoltaic Geographical Information System (PVGIS), PVWatts and RETScreen, used for quick estimations and calculations relevant to photovoltaic (PV) electricity production. This work spots the differences between these three software packages when used to estimate the ins and outs of variously sized theoretical PV arrays. Real measurements of existing PV parks installed in Greece (i.e., a real roof integrated PV array of 9.6 kWp, a PV plant of approximately 105.6 kWp, and a 98.4 kWp installation featuring a 2-axis tracking mechanism), provided data compiled over 24 months and allowed the assessment of the theoretical calculation results of the major software.