The ambitious targets set by the European Union within the framework of the Energy and Climate Plan (PNIEC) concerning the decarbonization of the electric system are favoring the progressive increase in photovoltaic capacity installation. This sector is experiencing a greater market diffusion of high-efficiency monocrystalline silicon modules, among which the Passivated Emitter Rear Cell (PERC) technology is now firmly established, while more recently introduced are the bifacial Heterojunction (HJT) and Interdigitated Back Contact (IBC) modules. In this context, the present study aims to analyze the potential environmental impacts generated by three photovoltaic technologies, PERC, bifacial HJT, and IBC, installed both in an 84.73 MW utility-scale ground-mounted plant and in a 3 kW residential rooftop installation.

In order to provide the broadest spectrum of possible details, the study considers various hypothetical scenarios, namely: (i) different cell technologies, (ii) two PV systems, an 84.73 MW utility-scale plant (ground-mounted) and a 3kW residential-scale plant (rooftop), (iii) two different support structures for the utility-scale plant (solar tracker and fixed structure), (iv) different module exposures for roof-mounted systems, in addition to the optimal one with the modules facing south, also east and west exposures, (v) installation in the two hypothetical sites of Catania and Piacenza . The potential impacts were evaluated following the Life Cycle Assessment approach, in accordance with ISO 14040 and ISO 14044 standards, considering the entire life cycle from the initial processing of raw materials to module disposal.

The analysis confirms the correlation between energy yield (the ratio between total annual energy produced and the solar installed capacity) and environmental impacts resulting from the generation of 1 kWh, highlighted by both the greater benefits achievable from the Catania site compared to Piacenza site and the advantages attainable from south-facing module orientation compared to other orientations. Comparing the two types of installations, rooftop and ground-mounted, the lesser contribution of the ground-mounted plant emerges, driven by the higher energy yield achievable due to better module exposure and inclination also thanks to the use of trackers. For all three technologies analyzed, it emerged that the greatest contribution in the generation of environmental impacts in the production of electricity from photovoltaic is associated to the module manufacturing, whose main criticality lies in the silicon wafer production processes.

The Report is available on the Italian site