A disclosed apparatus for generating electrical power has, according to one embodiment of the invention, a plurality of tubular solid oxide fuel cells contained in a reaction chamber. The fuel cells are secured at one end thereof in a manifold block, the other ends thereof passing freely through apertures in a baffle plate to reside in a combustion chamber. Reaction gases are supplied to the insides of the tubular fuel cells from a plenum chamber below the manifold block and to the reaction chamber surrounding the outsides of the fuel cells through an annular inlet path, which may include a reformation catalyst. The gases inlet path to the plenum chamber, and the annular inlet path surround the reaction chamber, are both in heat conductive relation with the reaction chamber and the combustion chamber, and raise the gases to formation and reaction temperatures as appropriate.