Total Energy and Total Power for the SOEC: Critical Role of Area Specific Resistance in Hydrogen Production Rate

This paper develops the governing Total Energy (TE) (kilowatt-hours per kilogram hydrogen) and Total Power (TP) equations for Solid Oxide ElectrolyzerCells (SOECs) and Solid Oxide Fuel Cells (SOFCs). The TE equation includes heat input, exergetic flows, enthalpy of vaporization, pressurization, heat loss, area specific resistance (ASR), etc. The TE equation developed, as it would happen, correlates well with the Idaho National Laboratory (INL) proven SOEC performance of 45 kilowatt-hours per kilogram hydrogen at 20 bars and 725 K. TE is the key performance equation necessary for designing, predicting, and planning for SOEC and SOFC performance and cost. The ASR has a critical role in SOEC TE and TP. The ASR and the targets for ASR necessary to meet important DOE performance targets are discussed.