Figure details the required PV area and the relative fraction of time in which the system operates in storage mode (i.e., when the chemical synthesis reactor is in operation). The error bars report the variability due to data incertitude (e.g., effective utilisation of the solar panels) and to the different possible vehicle technology used (car type). As already hinted by figure , the energy harvesting area to feed BEVs is much lower than for FCEVs, due to the higher efficiency of the global process (harvest-to-wheel). The surface required to feed the BEVs is in the order of 800 ⋅ 10 3 m 2 , while the same for FCEVs is around 1800 ⋅ 10 3 m 2 .