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The purpose of this article is to realize a review of studies dealing with life cycle assessment of electric grids or their components, in order to put in evidence methodological aspects to be considered with particular attention or requiring further deepening in future researches. After a preliminary bibliographic screening, the review analyses 16 scientific articles. The review considers 16 studies which are all based on a life cycle perspective and pays particular attention on some methodological issues such as: functional unit definition, selection of the impact categories, energy mix taken into consideration in order to quantify the environmental impact associated with grid losses, and end of life of grid components. The review considers, also, the analysed studies’ compliance to ISO 14040 recommendations. All the 16 studies have a good degree of compliance with ISO 14040. Concerning impact categories selection, the review showed a wide set of impacts taken into consideration: some categories are frequently utilized while others are present only in few studies. The analysis puts in evidence that recycling is a crucial aspect, determining a sensible reduction of impacts, which in some cases can compensate for the total impact of the end-of-life stage. Energy losses have a great influence on the overall impact. Neglecting losses in the valuation of networks or resistive components may be too simplifying, if not even misleading. Selecting a suitable functional unit is not an easy task. Beyond the specific outcomes, the analysis puts in evidence two general research needs. First, the definition of functional unit: some authors use a very specific functional unit which allows a correct description of the service provided by an electricity network while others use a functional unit allowing easier comparison with other studies. Second, considering the loss relevance and the infrastructure lifespan, an appropriate evaluation of the electricity mix is crucial.

PURPOSE: The purpose of the study is to compare the performances of two passenger cars: an electric vehicle (EV) and an internal combustion engine vehicle (ICEV) paying particular attention to the production of electricity that will charge the EV. Even if many similar comparative life cycle assessments (LCAs) exist (Nordelof et al. J Life Cycle Assess 19(11):1866–18990, 2014), only few have focused their attention on evaluating which is the kind of electricity that will recharge EV batteries (Hawkins et al. Int J Life Cycle Assess 17(8):997–1014, 2012). METHODS: Despite its relevance, many EV LCA studies have used a ready-to-use dataset to evaluate the power mix that supplies electricity to EV. The present paper tries to better define the power mix that recharges EV batteries in Italy according to the national power system and the national electric market rules. A 2013 and a 2030 scenario have been developed in order to understand effects in short and middle term. Life cycle inventory of electricity for EV has been estimated modifying available datasets according to official Italian data on power plants’ efficiency and emission rates. Finally, also for the ICEV use phase, existing dataset have been modified for fuel consumption and regulated emission according to the National Inventory Report results (ISPRA 2014) RESULTS AND DISCUSSION: In both 2013 and 2030 scenarios, the power mix that in Italy supplies energy to EV is dominated by fossil fuel power plants. Nevertheless, due to the fact that more than the 60 % of this energy is produced in efficient combined cycle gas turbine power plants, EV performs better than ICEV in almost all the impact categories considered except for human toxicity and eutrophication, the only two impact categories in which the EV car, mainly due to battery manufactory, presents more relevant potential impacts. ICEV impacts are always dominated by well to wheel phases (use phase and fuel production). EV car and battery manufacturing have higher impacts for all categories than ICEV car manufacturing. CONCLUSIONS: The study demonstrates that electricity supplied in Italy to EV today is, and will probably be in 2030, mainly produced by fossil fuel power plants. Nevertheless, the EV proves to be able to reduce, with respect to ICEV, those impacts it is supposed to reduce: air acidification, photochemical oxidant formation, and also greenhouse gases. Trade-offs are, as foreseeable, eutrophication and human toxicity due to EV car and battery manufacturing.