What is it?
Solid oxide electrolysis uses thermal energy from heat in combination with electrical energy from an electric current to synthesise hydrogen, using a ceramic solid oxide electrolyte membrane.
Why is it important?
Solid oxide electrolysis makes use of heat to significantly reduce the required electrical energy input for hydrogen production.
- Inputs: Water, heat, electricity, carbon dioxide (optional)
- By-products: Oxygen, carbon monoxide (if carbon dioxide input)
- Operating temperature: 700°–800°C
- Energy efficiency: (up to 82% system level efficiency claimed to date)
- Higher electrical efficiencies compared to AE/PEM can already be achieved and up to 10 kw systems have been demonstrated by R&D labs as well as commercial start-up companies
- High energy efficiency
- Non-noble materials
- Low (projected) capital cost for MW scale system
- Reversible operation as fuel cell is feasible
- Can be used for the electrolysis of CO2 to CO, or the co-electrolysis of CO2 and H2O to syngas (H2 and CO)
- Reduced electrical input requirement due to use of thermal energy, which could be sourced from waste heat
- High temperature operation – heat supplied must be of an appropriate quality (sufficiently high temperature)
- Poor lifetime due to mechanically unstable electrodes (cracking), brittle ceramics and sealing issues
- Limited flexibility: constant load recommended to achieve better efficiencies and avoid cell breakdown
- Ceramic materials have low relatively durability however SOFC system using same materials are now commercial and have been demonstrated to have sufficient stability for commercialisation and deployment
- Improve electrode performance
- Demonstrate integration with green energy sources at scale
- Increase lifetime of ceramic materials for ongoing high temperature operation
- Understand fundamental reaction mechanism and degradation behaviour
Known active organisations
- Deakin University