The final goal of this study is to determine the average yearly final cost of the car fuel (electricity or H2). This involves considering both the direct production of the fuel when renewable electricity is available and the recovery of electricity or H2 from the stored intermediate molecules when renewable electricity is not sufficient to cover the demand. To contextualise the relevance of the study, the findings are then applied to a case study relative to the city of Zurich, where several biogas plants are available and could be used as a platform for fuel production via power-to-X. The fuels can be transported to a centralised fuelling station, where they are used to produce electricity or H2 at the times when renewable energy is not available in sufficient amount. The centralised electrification or reforming reduces the cost of carbon capture. The case study allows performing a thoroughly economic calculation referring to real costs recorded at the location, validating the assumptions of this work versus existing geographical and operation data.