Sunlight irradiates one or more photovoltaic components, which can generate electricity.
Technology
What is it?
Sunlight irradiates one or more photovoltaic components, which can generate electricity. One or more photovoltaic components can be integrated with catalysts to create photoelectrodes or can be electrically connected to standard catalyst-coated electrodes. Hydrogen and oxygen are produced at different (photo)electrodes, separated by a membrane.
Why is it important?
Photoelectrochemical water splitting makes use of sunlight to convert water to hydrogen, with the option of supplementing the process with some electrical energy.
Characteristics
- Inputs: Water, sunlight, electricity (optional in some designs)
- By-products: Oxygen
- Operating temperature: Ambient
- Energy efficiency: Low (however uses direct sunlight). Efficiencies of 10-30% have been demonstrated for stand-alone (no added electricity) lab-based systems. DOE have set target STH > 20% using low cost materials.
Benefits
- Integrated solar capture and hydrogen production
- Uses sunlight as primary energy source
- In some designs, additional electrical energy input can be applied
- Separation of H2 and O2
- Zero-to-low carbon emissions
- Can leverage existing solar cell and electrocatalyst technologies
Limitations
- Photoelectrodes absorb a limited range of sunlight
RD&D priorities
- Continue materials development
- Develop low-cost, stable catalyst and co-catalysts materials
- Develop low-cost, high-efficiency photoelectrode materials
- Improve long term stability of photoelectrodes
- Improve system integration and design
- Improve membrane and electrode durability
- Conduct technoeconomic analysis of PEC based solar hydrogen systems versus PV-electrolysis systems
Known active organisations
- The Australian National University
- Macquarie University
- Monash University
- Queensland University of Technology
- RMIT University
- The University of Adelaide
- The University of Melbourne
- The University of New South Wales
- The University of Newcastle
- The University of Queensland
- Western Sydney University