Since the beginning of 2008 HELION sells containerized autonomous fuel cell backup power systems ranging from 100 kVA to 200 kVA. These backup systems, in the MISTRAL line, have been conceived on the basis of design studies and the architecture of the first functional containerized autonomous prototype produced by HELION, the MISTRAL V1. This was of around thirty kVA, and coupled to the HELION installations in order to backup the High Temperature Electrolysis benches actually in operation. Backup systems of the MISTRAL line, offered by HELION benefit from the feedback from this prototype. They can be fitted with an UPS (uninterruptible power supply) and comprise integrated gas storage giving them an autonomy of 4 hours. This can be increased as desired by connecting external gas racks or by connecting to a low pressure gas network.