In the context of the development of zero emissions personal vehicles, compressed air cars have been proposed, as alternative solutions to electric solutions, with a small energy content leading to a limited range, but with interesting properties regarding aging phenomena, costs, and possibility to be recharged rapidly. This paper discusses the questions of energy – and power-density of alternative vehicles like electric and compressed air solutions. It proposes and describes a concept of a fast filling station recently developed. The system uses a local reservoir that is precharged by an isothermal compression machine. The fast transfer itself uses a low dissipation nozzle limiting the transfer flow rate. Then, in order to recover the heat produced during the fast pressure rise in the vehicle’s reservoir, a dedicated recirculation system is activated in order to reach finally the higher air mass-density in it, corresponding to the best energy content on board. Simulation results are presented, and an experimental setup is described.