Abstract: A solid oxide cell assembly includes a housing that further includes a base plate, a cover and one or more side walls. one or more solid oxide cell stacks are positioned on the base plate. at least one radiant heater element is positioned inside the housing and is configured to emit radiant heat onto the one or more solid oxide cell stacks. the at least one radiant heater element is formed as one of a heating tube and a heating plate and comprises a plurality of separately controllable segments each comprising separate power connections. The solid oxide cell assembly is further formed as a high temperature electrolysis cell assembly.