A fuel cell column includes first and second fuel cell stacks, a fuel manifold disposed between the first and second fuel cell stacks and configured to provide fuel to the first and second fuel cell stacks, and first and second dielectric separators located between the fuel manifold and the respective first and second fuel cell stacks, and configured to electrically isolate the respective first and second fuel cell stacks from the fuel manifold. The first and second dielectric separators each include a top layer of a ceramic material, a bottom layer of the ceramic material, a middle layer disposed between the top and bottom layers and including a material having a lower density and a higher dielectric strength than the ceramic material, and glass or glass ceramic seals which connect the middle layer to the top and bottom layers.