Solid oxide cell consists of all-solid electrolyte and electrodes. The widely used oxide ion electrolyte materials include yttria doped zirconia (YSZ), samaria or gadolinia doped ceria (SDC or GDC) and LSGM. Depending on the type of the electrolyte, a working temperature in the range of 600~850°C is necessary to ensure an enough ionic conductivity necessary for the electrochemical reactions taking place inside the cells.

Under the fuel cell mode, hydrogen or hydrocarbon containing fuels (such as natural gas, biomethane, carbon monoxide, etc.) can be converted electrochemically to water or carbon dioxide, producing electricity and heat simultaneously. Since there is no combustion of the fuel taking place inside fuel cell, and all fuel cell components are generally working at the same temperature, the fuel cell efficiency is not limited by the Carnot efficiency.

For SOFC systems, the efficiencies for power generation and combined generation of heat and power (CHP) are above 60% and 90%, respectively. Although fuel cells with large size can be produced, the most common size of a single cell is in the range of 100cm² and 200cm². Depending on the size and working conditions, each single cell may have an electrical power of 30~100W. Therefore, multiple cells need to be connected in stacks to reach the desired power range.

The standard SOFC stack from VERMES SOC Technology has a nominal power of 1.5kW in the temperature of 700°C and 750°C.