Solid Oxide Electrolyser Cell - Considerations

Considerations

Advantages of solid oxide-based regenerative fuel cells include high efficiencies, as they are not limited by Carnot efficiency. Additional advantages include long-term stability, fuel flexibility, low emissions, and low operating costs. However, the greatest disadvantage is the high operating temperature, which results in long start-up times and break-in times. The high operating temperature also leads to mechanical compatibility issues such as thermal expansion mismatch and chemical stability issues such as diffusion between layers of material in the cell

In principle, the process of any fuel cell could be reversed, due to the inherent reversibility of chemical reactions. However, a given fuel cell is usually optimized for operating in one mode and may not be built in such a way that it can be operated in reverse. Fuel cells operated backwards may not make very efficient systems unless they are constructed to do so such as in the case of solid oxide electrolyzer cells, high pressure electrolyzers, unitized regenerative fuel cells and regenerative fuel cells. However, current research is being conducted to investigate systems in which a solid oxide cell may be run in either direction efficiently.