NOVELTY - A fuel cell power plant (19) comprises a coolant reservoir containing a coolant mixture of water with a miscible, freeze depressing substance, where each of the fuel cell coolant channels is in fluid communication with the coolant reservoir. The coolant mixture migrates from coolant channels into the water transport plate of each fuel cell. At least some water within the coolant mixture along with some process water evaporates into the reactant gas flow field channels cool the fuel cells.    USE - Used as power plant.    ADVANTAGE - The fuel cell power plant has reduced volume, eliminates or reduces freezable water, avoids having freezable liquid in contact with moving parts, and shortens startup time by reducing cell stack thermal mass.    DETAILED DESCRIPTION - A fuel cell power plant comprises:    (1) a stack (20) of fuel cells, each fuel cell including hydrophilic, porous water transport plates with coolant channels, fuel reactant gas flow field channels and oxidant reactant gas flow field channels having inlets and outlets;    (2) a source (42) of oxidant reactant gas in fluid communication with inlets of the oxidant reactant gas flow field channels;    (3) a source of fuel reactant gas in fluid communication with inlets of the fuel reactant gas flow field channels;    (4) a coolant reservoir containing a coolant mixture of water with a miscible, freeze depressing substance, where each of the fuel cell coolant channels is in fluid communication with the coolant reservoir;    (5) a pump (22) for circulating coolant from the reservoir, through the fuel cell coolant channels and back to the reservoir; and    (6) a condenser connected to the outlet of at least one of the oxidant reactant gas flow field channels of the fuel cells.    The condensate of the condenser is in fluid communication (48) with the reservoir. The coolant mixture migrates from the coolant channels into the water transport plate of each fuel cell. At least some water within the coolant mixture along with some process water evaporates into the reactant gas flow field channels cool the fuel cells. Some of the water vapor in the reactant gas flow field channels is condensed in the condenser and returned to the reservoir where it mixes with coolant in the reservoir. The fuel cell includes membrane electrode assembly having a membrane with catalyst on both surfaces.    DESCRIPTION OF DRAWING(S) - The figure is a block illustration of a fuel cell power plant.    Fuel cell power plant (19)    Stack of fuel cells (20)    Source of oxidant reactant gas (42)    Fluid communication (48)