Solid Oxide Electrolysis Cell

A solid oxide electrolyzer cell, or SOEC, is a solid oxide fuel cell run in reverse, using a solid ceramic electrolyte at high temperature, typically between 500 and 850 degrees Celsius, to electrolyze water, and in some designs carbon dioxide as well, producing hydrogen gas, and in the carbon dioxide case carbon monoxide, along with oxygen. Because it runs hot, high temperature electrolysis of this kind is considered the most promising method of producing hydrogen from water, converting energy at high efficiency with a lower energy input than thermochemical or photocatalytic hydrogen production methods need, since electrolyzing water at room temperature, 25 degrees Celsius, requires 285.83 kilojoules of energy per mole on its own. That energy demand can be partly offset by heating the process with an external heat source such as a solar thermal collector or geothermal energy rather than electricity alone, letting an SOEC produce hydrogen, seen as a clean fuel that can be stored as an alternative to batteries or methane, more efficiently than lower temperature electrolyzer designs.