When looking at the global efficiency of the system (i.e., total electricity to customers/total electricity from PV), the efficiency value strongly favours the utilisation of methane as an electricity storage molecule. The efficiency values are calculated with a weighted average between the direct utilisation of renewable energy to feed mobility when available (ca 60-70 % of the year) and the used of stored molecule when renewable energy is insufficient. The resulting efficiency value for methane is 69.74%, while the value for methanol is 53.67%. This difference is originated by both the higher efficiency of electricity production from methane and by the larger amount of storage needed for the case of methanol. Note that the higher efficiency for the methane use in electricity production is mainly originated by the larger combustion enthalpy, which causes an increase in the Carnot efficiency of the thermodynamic transformation. In the best case, the energy penalty caused by using fuel storage to provide a constant autarchic renewable energy supply is thus ca. 30%. This value depends on the input profile used and would be decreased when the input is less subject to seasonality or vice versa. When looking at the global efficiency in H2 delivery to the customers (i.e., total H2 to customers/total electricity from PV), one can note that the differences are less pronounced, as methanol is a more efficient H2 storage molecule than methane, decreasing the negative effect caused by the larger amount of storage molecules needed. Nevertheless, methane remains the most efficient storage fuel, with 62.67% efficiency vs. 56.28% of methanol. Note that the maximum efficiency is mainly limited by the electrolyser, whose efficiency value is ca. 70%. To summarise the main findings of this study, table shows a rating of the four options studied with respect to the main performance indicators of the system. The solutions involving H2 as final product are more favourable concerning the storage efficiency, fuel handling at the gas station (as H2 is easier to store temporarily than electricity) and possibility of carbon capture (as this can be employed as pre-combustion carbon capture). Electricity is instead the preferred final product for the PV surface required (as the global efficiency for mobility is higher), for the quantity of storage molecule to produce, for CO2 feed required and for the efficiency in the final use (more km driven with the same amount of fuel). As highlighted previously, when the storage molecule plays a role in defining a property (i.e., for storage efficiency, PV surface, storage and CO2 amount) methanol is generally a better vector than methane to store H2, while the opposite holds for electricity.