A HEALTH CHECK OF THE ITALIAN SOLAR PHOTOVOLTAIC PARK USING SATELLITE-BASED SOLAR RESOURCE DATA

摘要

At country level, the average Performance Ratio PR for Italy is presently low (68.6% in 2016). At regional level we observe a strong dispersions in the results and the presence of some outliers. Regions with the lowest PR are Lombardia, Liguria, and Campania. Puglia, the region with largest average size of solar plants exhibits the highest PR. We then refine our analysis to province level calculating PR_(2016) values for the 108 Italian provinces using 2016 data, a year for which irradiation data are well aligned to long-term averages. With some outliers, the vast majority of PR_(2016) for the different provinces lies between 60-70%. We then look for some correlations that can describe the strong scatter in the data presented: (1) it is difficult to observe a clear correlation between average system size in the province and PR for average sizes below 45 kW. On the other hand, above this threshold, system size is generally a good indicator of good performance; (2) the residential (and building) density in the province (which can be correlated to some extent to increased shading losses, particularly for small/medium-size rooftop installations) has a strong impact on PR and can be described by a hyperbolic relation; (3) the effect of province elevation on PR is not clear, nevertheless, not necessarily provinces located at higher altitudes (and potentially increasingly affected by far shading) have lower PRs. These correlations are sometimes weak, but we believe that this analysis could be improved considerably by increasing the spatial granularity of the data and focusing on smaller geographical units, such as communes or even at the scale of the single PV plant.