In this study, two high voltage gain active Z-source dc/dc converters are proposed, which are suitable for renewable energy applications. The complete analyses of the proposed structures are presented and the suitable control method is proposed. The voltage and current stresses of all elements are calculated. Moreover, in order to recognise the advantages and disadvantages of the proposed converters, a comprehensive comparison between the proposed dc/dc Z-source converters with conventional converters are made. The efficiency of both proposed converters and the conventional ones are also compared. In addition, the application of the proposed topologies in fuel cell vehicle is proposed. Finally, in order to verify the theoretical analyses, simulation results in PSCAD/EMTDS software and experimental results of the prototype are presented.