
Global warming represents one of the defining challenges of our century, placing the long-term stability of human civilization at risk and making carbon neutrality a prerequisite for sustainable development. In this context, green hydrogen from renewable energy is a key energy carrier for deep decarbonization of industry, transport, and large-scale energy storage.
Green hydrogen from solar energy is central to future carbon-neutral energy systems. Today, most solar-driven hydrogen production relies on photovoltaic (PV) electricity to power water electrolysis. However, PV devices utilize only part of the solar spectrum efficiently: photons below the bandgap are not converted, and excess photon energy is dissipated as heat. Consequently, a substantial fraction of incident solar exergy remains underutilized, limiting overall solar-to-hydrogen (STH) efficiency.Spectral splitting provides a rational pathway to maximize solar utilization by directing high-energy photons to a PV cell and lower-energy photons to a thermal absorber. When optimized from a hydrogen-system perspective rather than PV efficiency alone, such co-designed architectures can significantly enhance overall exergy efficiency and hydrogen yield.The tasks for the student HiWi job are:(1) System-level optimization for solar hydrogen. Design a high-efficiency spectral-splitting photovoltaic-thermal architecture for green hydrogen production. The system will be optimized from a solar-to-hydrogen and exergy perspective, defining the optimal spectral cut-off, PV operating conditions, thermal temperature range, and coupling strategy to the electrolyzer.(2) Integrated co-design and performance assessment. Couple optical, electrical, thermal, and electrochemical models to evaluate overall system efficiency and hydrogen yield per unit area. The metasurface and the PV-thermal subsystem will be co-optimized to maximize annual hydrogen production rather than individual component performance.The candidate should have the background on mechanical engineering and/or electrical engineering. This is a collaboration project between IMT and INT in the north campus of KIT.Application documents: CV