There is provided a fuel cell element including a substrate and one or more fuel cells thereon, the one or more fuel cells not entirely covering the substrate. The one or more fuel cells each include a solid state, non-polymeric first electrode layer, a solid state, non-polymeric second electrode layer, and a solid state, non-polymeric electrolyte layer between the first and second electrode layers. The substrate includes one or more porous regions, or being entirely porous, the one or more fuel cells each being supported by one or more porous regions of the substrate. At least one, or part of one, of the porous regions of the substrate are not sealed by electrolyte. Arrays of fuel cell elements of the invention are also provided, as are stacks of fuel cell elements or arrays of the invention.