Abstract: A high temperature fuel cell (10) having first and second temperature zones (14, 16) for directly converting carbon fuel (12) to electrical energy comprises a first heat source (22), a second heat source (26), and a housing (18) that includes a non-porous section (15) and a solid electrolyte (30) having first and second electrolyte surfaces (32, 34) to which first and second electrodes (36, 38) are electrically connected. The first heat source (26) establishes first temperature zone (14) in the vicinity of the solid electrolyte (30) for adjusting the conductivity of the solid electrolyte (30) and electrodes (36, 38). The second heat source (26) is positioned in the vicinity of non-porous section (15) of housing (18) a distance from first heat source (22) to establish second temperature zone (16).