Life Cycle Assessment of a ground-mounted 1778kWₚ photovoltaic plant and comparison with traditional energy production systems

Photovoltaic system is a technology for the production of electricity from renewable sources that is rapidly expanding thanks to its capability to reduce the energy consumption from traditional sources and to decrease the air pollution. During the operational phase, there are no emissions and the only input is represented by solar power. However, it should be noted that, considering the entire life cycle of a plant, photovoltaic systems, like any other means of electricity production, give rise to emissions, that focus especially in the manufacturing stage and installation of components. The present work aims at evaluating the environmental impact, and therefore the actual sustainability of this technology, examining a ground-mounted 1778.48kWₚ photovoltaic plant, realized by TerniEnergia S.p.A. and located in Marsciano (Perugia, Italy). The analysis is conducted using the methodology of Life Cycle Assessment (LCA), which allows to consider all stages of the life cycle, from the extraction of raw materials to the plant’s disposal (“from a cradle to grave perspective”). In particular, the study takes into account the soil preparation, the installation of fence and electrical substations of low and medium voltage, the mounting of support structures, also with reference to hot dip galvanizing process, the production of modules, their installation, the wiring apparatus and the network connection. The transport of all components to the installation site is considered for each stage that is examined. The end of life scenario of the plant is also evaluated. The possibility to collect many detailed information in the construction site, during the building phase, adds value to the study. The analysis is carried out according to UNI EN ISO 14040 and UNI EN ISO 14044, which regulate the LCA procedure. The LCA modelling was performed using SimaPro software application and using Eco Indicator 99 methodology. The results of the analysis allows to calculate some important parameters like EPBT (Energy Pay-Back Time), EROEI (Energy Return on Energy Invested), CO₂ emissions and GWP100 (Global Warming Potential). Finally, the environmental impact of photovoltaic plant is compared to that of some traditional energy production systems.