A systems engineering review on the integration of solar concentrators with photoelectrochemical processes

Photoelectrochemical (PEC) processes offer several pathways to decarbonisation, but few studies have demonstrated technology readiness levels (TRLs) beyond 4 and 5. Scaling challenges and the high levelised cost of energy of current PEC processes can be addressed by integrating concentrating solar optics. However, PEC research is primarily focused on materials development and reactor engineering, with limited consideration of constraints imposed by solar concentrators. Similarly, no clear design criteria exist for developing solar concentrators for commercial PEC processes. In this work, a systems engineering approach is used to establish a framework for integrating PEC processes with solar concentrators. Uncertainty regarding the PEC device configuration and its robustness to dynamic real-world conditions makes it challenging to quantify specifications at subsystem interfaces. On the other hand, existing commercial solar concentrator technology offers mature solutions but requires shifting design objectives to suit PEC processes. By systematically addressing the requirements at each subsystem interface, the field can progress beyond laboratory demonstrations toward commercial-scale solar fuel production facilities needed for a sustainable energy future.