**1. Introduction**

European Commission energy policy at the 2030 horizon aims to strengthen the 20-20-20 objectives and, at the same time, is a precondition for 2050 goals of the long-term strategy to reduce greenhouse gas emissions [1]. In this framework, the Italian Integrated National Energy and Climate Plan (INECP) [2], intends to accelerate the transition from traditional fuels to renewable sources.

Due care must be paid to ensure that the energy and climate objectives are compatible with the objectives relating to the landscape protection, the quality of air and water bodies, the safeguarding of biodiversity and soil protection. As a matter of fact, the necessary measures to increase decarbonisation of the system, involve power plants and infrastructure deployment that have environmental impacts [2].

The present study is aimed at evaluating, from an environmental point of view, the Italian electricity generation scenarios at 2030 (devised in the INECP) and at comparing them with the current electricity generation mix.

At this purpose, Life Cycle Assessment (LCA) methodology according to ISO 14040 [3] has been adopted. According to ISO 14040 [3] LCA is a methodology that "*addresses the environmental aspects and potential environmental impacts throughout a product's life cycle from raw material acquisition through production, use, end-of-life treatment, recycling and final disposal (i.e., cradle-to-grave)*". LCA can be a powerful tool for supporting energy planning for several reasons:



For these reasons, LCA have been widely used in literature to assess present and future national electricity mix scenarios sustainability [6–9]. Some works put also in evidence issues and explore new methodological solutions. For example, the study [10] on the life-cycle assessment of the large-scale implementation of climate-mitigation technologies, addresses the impacts on the electricity and uses assumptions of technical improvements also in material production technologies. Reference [11] combines different approaches in a "technology hybridized environmental-economic model with integrated scenarios", to predict the environmental impacts of energy policy scenarios. Recent studies evaluate, with a life cycle approach, energy scenarios at a national (Spain [6] and Germany [7]) or regional (Sicilia region in Italy [9]) scale. According to [6], that provides an investigation into the sustainability of the electrical system in Spain, for future scenarios (2030 and 2050), the most ambitious projections in terms of renewable penetration perform best in terms of environmental performance and the scenario considering higher fossil fuel contributions performs worst in all sustainability indicators. As demonstrated in [12] the 2030 New York scenario, based on 70% of renewable energies, dramatically reduces both carbon dioxide emissions and cumulative energy demand. Finally, the life cycle assessment of UK electricity scenarios to 2070 was studied by [8]. According to the LCA results, the decarbonisation of the UK electricity mix introduces many questions regarding sustainability and shows that the level of decarbonisation achieved and the method taken can lead to significantly diverging outcomes, each involving trade-offs and compromises.

In this framework, the present study evaluates the Italian energy strategy, starting from a detailed and fully representative LCA of the Italian electricity system. In order to represent the variability of energy sources, fuels and transformation technologies, the study takes into consideration a great number of different electricity power plant types for current and future electricity mixes. For operation phase of fossil thermoelectric sector, updated primary data for the main air emissions have been used. In fact, also considering the increasing role of electricity as an energy carrier, data quality and representativeness, is a crucial issue in life cycle inventory of electricity supply [13].

Two scenarios at 2030 have been used in this work, in order to evaluate the effect of the electricity system evolution on the environmental indicators. These scenarios are described and utilized as the basis of the Italian Integrated National Energy and Climate Plan [2]. For Italian current electricity system, two years are taken into consideration: 2016 and 2017. Year 2016 is the base year used for INECP scenarios elaboration, while year 2017 is the most recent year for which statistical data were available (when performing the study) and it is considered in order to present an updated LCA of present Italian electricity system.

Goal and scope of the LCA, inventory and impact assessment results are described in the following paragraphs.
