The invention provides solid oxide fuel cell devices and systems, each including an elongate substrate having an active end region for heating to an operating reaction temperature, and a non-active end region that remains at a low temperature below the operating reaction temperature when the active end region is heated. An electrolyte is disposed between anodes and cathodes in the active end region, and the anodes and cathodes each have an electrical pathway extending to an exterior surface in the non-active end region for electrical connection at low temperature. The system further includes the devices positioned with their active end regions in a hot zone chamber and their non-active end regions extending outside the chamber. A heat source is coupled to the chamber to heat the active end regions to the operating reaction temperature, and fuel and air supplies are coupled to the substrates in the non-active end regions.