Abstract: A ceramic fuel cell(s) is supported in a heat conductive interconnect plate, and a plurality of plates form a conductive heater named a stack. Connecting a plurality of stacks forms a stick of fuel cells. By connecting a plurality of sticks end to end, a string of fuel cells is formed. The length of the string can be one thousand feet or more, sized to penetrate an underground resource layer, for example of oil. A pre-heater brings the string to an operating temperature exceeding 700° C., and then the fuel cells maintain that temperature via a plurality of conduits feeding the fuel cells fuel and an oxidant, and transferring exhaust gases to a planetary surface. A manifold can be used between the string and the planetary surface to continue the plurality of conduits and act as a heat exchanger between exhaust gases and oxidants/fuel.