## 4 Results and Discussion  
### First Scenario Outcomes  
In this section, the results obtained considering only the addition of batteries to the already installed RES power generation system are discussed. As already pointed out, this solution needs to be explored because the addition of batteries can better exploit the installed RES plants. The \"functional unit\" of the LCA is 1 MWh of stored energy. This means that it is 1 MWh of electricity produced using renewable energy, when available, stored in the batteries, which is then released when required by the users. In the calculation, battery efficiency is considered. In the reference case, the diesel engine produces this electricity when required by the users. Figure 2 summarizes the damage assessment computed with the ReCiPe 2016 method-Endpoint (H) [43] for Pantelleria. This method summarizes the impact of a process in three areas of protection: human health, ecosystem quality, and resource scarcity. The results clearly show that the use of the batteries gives a significant reduction of the impacts in overall categories with respect to the reference scenario (actual energy mix as listed in Table 3). In all the categories, the impacts are lower than 6% of the impacts due to production by the diesel engine. Figure 3 shows in greater detail the impact characterization since the mechanisms affecting the three areas of protection are indicated separately. In this case, it is clear that the use of LFP has the highest impact on stratospheric ozone depletion, ionizing radiation, water consumption and eutrophication, land use, and mineral resource scarcity. The impact \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Annual Production**} & \multicolumn{3}{c}{**New Installed Power**} & **Installed Batteries** \\ \hline \multirow{2}{*}{**Island**} & **PV** & **Wind** & **Diesel** & **PV** & **Wind** & **(kWh)** \\  & **(MWh)** & **(MWh)** & **(MWh)** & **(kW)** & **(kW)** & **(kW)** \\ \hline Ventotene & 268 & 79 & 2363 & 840 & 60 & 4000 \\ Pantelleria & 8880 & 1600 & 34,070 & 6000 & 825 & 30,000 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Energy mix of the islands in the advanced energy scenario (also named “second scenario”). is even higher than the use of diesel. Among the batteries, the VRFB presents the highest values for particulate emissions and terrestrial acidification. The NIB presents the lowest value for the mineral resource consumption, about 3 times lower than LFP, confirming the advantage of not using lithium, which has scarce reserves. Starting with this final observation, it is interesting to analyze in detail the phases of LFP because it has the worst results among batteries. Figure 4 shows the characterization of the lone assembly phase and highlights that the main impact is attributable to the positive electrode because it uses lithium and tetrafluoro  
Figure 3: Impact characterization for the different batteries and of the reference case (ReCiPe 2016 method-Endpoint (H)). Figure 2: Comparison of the impacts for the different batteries and of the reference case (ReCiPe 2016 method-Endpoint (H)). roethylene. In particular, its impact is around 20% of the global impact on human health, ecosystem, and use of resources. BMS greatly affected human health (about 21%) due to the use of electronic components and the liquid crystal display. A great impact is also linked to the use of electricity during the assembly phase. Transport accounts for about 14% in the use of resources. Figure 5 shows the impact of the end-of-life phase for the LFP battery. It can be noted that the reuse of metals and plastic has a positive effect on overall impact, which for some categories exceeds the impact of the waste treatment. The highest impact on health and environment is caused by the disposal of electronic waste, while for resource use the main impact is due to the pyrometallurgical and hydrometallurgical processes needed to recover lithium, cobalt, and nickel.