This study shows that battery electrical vehicles (BEV) or fuel cell electrical vehicles (FCEV) can efficiently be supplied continuously with renewable electricity by coupling the direct supply of electricity or H2 with the storage of electricity in synthetic fuels produced from biogenic CO2. Methane and methanol were considered as the storage molecules. The system was designed according to the input/output profiles of the city of Zurich, using biogas as CO2 supply and photovoltaics as renewable electricity input. It was underlined that the power-to-X system would need to operate for about 70% of the time, while for the remaining time, the supply of electricity or H2 would rely on combustion/reforming of the stored molecules. Due to the different efficiencies of BEV and FCEV, direct electric mobility is advantageous from various perspectives, including the global efficiency of the system including storage. From a pure storage point of view, methane is the best option for electricity storage, while methanol is best for H2 storage.