Solid oxide fuel cell stack

A fuel cell stack comprising:

• a plurality of modules, each module comprises an elongate hollow member, each module has at least one passage extending longitudinally through the hollow member for the flow of a reactant, each hollow member has a first flat surface and a second flat surface arranged substantially parallel to the first flat surface, a first one of the modules includes a plurality of fuel cells, the fuel cells are arranged on at least one of the first and second flat surfaces of the first one of the modules, a first end of the first one of the modules has a first integral spacer formed integrally with said module to provide space from a second one of the modules, the first integral spacer comprises a third flat surface arranged such that it is non coplanar with the first flat surface of the first one of the modules, a second end of the second one of the modules has a second integral spacer formed integrally with the second one of the modules to provide a spacer with the first one of the modules, the second integral spacer comprises a fourth flat surface arranged such that it is non coplanar with the second flat surface of the second one of the modules, the third flat surface of the first one of the modules is arranged to abut the fourth flat surface of the second one of the modules, the third flat surface has at least one aperture for the flow of reactant, the fourth flat surface has at least one aperture for the flow of reactant and the at least one aperture in the third flat surface is aligned with the at least one aperture in the fourth flat surface to provide a fluid connection between the first and second ones of the modules without additional separate spacers between the first and second ones of the modules.