Patent ID: 7645531

Claim:
A fuel cell power plant ( 19 ) comprising: a plurality of fuel cells ( 70 , 70 a , 70 c ) arranged in a stack ( 20 ), each fuel cell including a unitized electrode assembly ( 72 ) having a proton exchange, polymer electrolyte membrane disposed between catalysts of an anode and a cathode which each have a gas diffusion layer, a porous, at least partly hydrophilic anode water transport plate ( 75 ) with fuel reactant gas flow channels ( 74 ) adjacent the anode gas diffusion layer, and a porous, at least partly hydrophilic cathode water transport plate ( 81 ) with oxidant reactant gas flow channels ( 82 ) adjacent the cathode gas diffusion layer; a plurality of water channels disposed between said anode water transport plate and said cathode water transport plate of adjacent fuel cells; means providing water to said water channels when said fuel cell power plant is operating, said water transferring between said water channels and said water transfer plates; characterized by: means configured so that water is retained in said water channels and said water transport plates when said fuel cell power plant is inoperative.