NOVELTY - Electrochemical fuel cell comprises first and second monolithic electrically conducting flow field-bipolar plate assemblies (4). The monolithic flow field-bipolar plate assemblies comprise first and second porous metal flow fields (8) directly bonded to opposite sides of an electrically conducting gas barrier (9) by metallurgical bonds.    USE - For electrical power generation.    ADVANTAGE - The invention has low weight per unit area. It is electronically conductive and inexpensive. The use of porous metal flow fields allows gas flow without mechanically cut grooves.    DETAILED DESCRIPTION - An electrochemical fuel cell comprises first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged parallel to each other so that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow field-bipolar plate assembly. The flow field-bipolar plate assemblies are electrically and mechanically connected by intervening layers. The intervening layers comprises first electrically conducting intermediate layer bonded directly to the inside surface of the first flow field-bipolar plate assembly, a second electrically conducting intermediate layer bonded to the inside surface of the second flow field-bipolar plate assembly, first and second electrode bonded directly to the inside surface of the first and second electrically conducting intermediate layer, respectively, and polymer electrolyte membrane (7) bonded directly to both of the electrodes (6). INDEPENDENT CLAIMS are also included for:    (I) an electrochemical fuel cell stack comprising two electrically conducting end-plates and electrochemical fuel cells disposed between the endplates;    (II) a method of making a fuel cell stack comprising disposing between two electrically conducting endplates, an electrochemical fuel cells;    (III) a method of generating electrical power comprising supplying hydrogen and oxygen to an electrochemical fuel stack;    (IV) an air cooled condenser for use with a fuel cell stack comprising a three-dimensionally reticulated porous metal condensing element and a three-dimensionally porous metal cooling element, where the three-dimensionally porous metal condensing element is disposed between two gas impermeable barriers by continuous metallurgical bonds and three dimensionally reticulated porous metal cooling element is disposed between and bonded directly to two other gas impermeable barriers;    (V) an evaporatively cooled internally humidified fuel cell stack comprises fuel cells and an air cooled condenser in fluid communication with the fuel cells;    (VI) a method of cooling an electrochemical fuel cell comprising placing the electrochemical fuel cell in fluid communication with an air cooled condenser;    (VII) a flow field-bipolar plate assembly for an electrochemical cell comprising first and second three dimensional reticulated porous metal flow- fields bonded to opposite sides of electrically conducting gas impermeable barrier by continuous metallurgical bonds; and    (VIII) a method of delivering a gas to a fuel cell electrode comprising delivering the gas to a porous metal flow-bipolar plate assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a fuel cell.    flow field-bipolar plate assemblies (4)    intermediate layer (5)    electrodes (6)    polymer electrolyte membrane (7)    porous metal flow field (8)    gas barrier (9)