Direct methanol fuel cell systems for backup power – Influence of the standby procedure on the lifetime

This paper compares different backup power systems for uninterruptible emergency power supply (UPS) in the kW-power range. The cost structure of direct methanol fuel cell systems (DMFCs) is deduced from a DMFC system developed for the replacement of batteries in small fork-lift trucks. The setup for new DMFC backup power systems will be further simplified and those systems will be operated without expensive sensors necessary for laboratory testing. A detailed cost structure of such systems is shown, and in a cost comparison the competitiveness to other existing UPS technologies is indicated. te of reduced sensor systems the efficient and secure operation of the system must be guaranteed. The demanded durability in case of UPS is ten years in discontinuous operation. To achieve the long term stability the right treatment of the stack during standby was identified by tests on single cells as well as on short stacks. A number of different standby procedures have been tested in order to identify how the MEAs must be treated in order to avoid premature degradation during standby.