The invention is a reversible fuel cell power plant (10). A reactant
switch-over assembly (48) is secured between a reducing fluid fuel source
(30), an oxygen containing oxidant source (24), and first and second flow
fields (20) (22) of a fuel cell (12). The switch-over assembly (48) first
directs a reducing fluid fuel stream to flow into the first flow field
(20) while it simultaneously directs the oxygen containing oxidant stream
to flow into the second flow field (22). Then, after a first half of a
useful life span of the fuel cell (12) but before a final one quarter of
the useful life span, the switch-over assembly (48) directs the reducing
fluid fuel stream to flow into the second flow field (22) while it
simultaneously directs the oxygen containing oxidant stream to flow into
the first flow field (20).
