Solid oxide fuel cell device and system

A solid oxide fuel cell device (10) comprising an elongate substrate having an exterior surface, an interior solid support structure, and a length that is the greatest dimension whereby the elongate substrate exhibits thermal expansion along a dominant axis that is coextensive with the length, an active reaction zone along a first portion of the length configured to be heated to an operating reaction temperature, and at least one cold zone along a second portion of the length configured to remain at a low temperature below the operating reaction temperature when the active reaction zone is heated, characterized in that a porous supporting electrode material (24 or 26) forms the interior solid support structure of the elongate substrate; in that one or more first fluid passages (14 or 20) reside within the porous supporting electrode material (24 or 26) coupled to a first fluid inlet in the at least one cold zone and extending at least partially through the active reaction zone to a first fluid outlet in one of the active reaction zone or an opposing cold zone; in that an electrolyte (28) lines the one or more first fluid passages (14 or 20) and a first electrode material (24 or 26) lines the electrolyte (28) whereby the electrolyte (28) separates the first electrode material (24 or 26) in the one or more first fluid passages (14 or 20) from the surrounding porous supporting electrode material (24 or 26), and wherein the porous supporting electrode material (24 or 26) is one of an anode material (24) or a cathode material (26) and the first electrode material (24 or 26) is the other of the anode material (24) or the cathode material (26); and in that a first electrical contact surface is electrically coupled to the first electrode material (24 or 26) and resides at a first exterior surface of the at least one cold zone and a second electrical contact surface is electrically coupled to the porous supporting electrode material (24 or 26) and resides at a second exterior surface of the at least one cold zone, each for electrical connection at the low temperature below the operating reaction temperature.