Hybrid Power-to-X System Offers Scalable Approach to Clean Energy Generation

Researchers from the Islamic University of Madinah have developed a novel hybrid power-to-X system that integrates solar thermochemical hydrogen production and the Graz cycle power generation. This system, which has been peer-reviewed, aims to achieve zero-emission, dispatchable power and storable hydrogen generation without relying on electricity-based electrolysis. The system utilizes solar energy through a central receiver and heliostat field, providing thermal energy for electricity generation and hydrogen production.

Key Takeaways:

• The hybrid system combines concentrated solar power, a vanadium chloride thermochemical hydrogen production cycle, and the Graz oxy-combustion power cycle to achieve zero-emission power and hydrogen generation.
• The system's flexibility and environmental performance are enhanced by incorporating a thermoelectric generator, proton exchange membrane electrolyzer, and carbon capture unit.
• A rigorous model validation and sensitivity analysis revealed a trade-off between exergy round-trip efficiency (ERTE) and CO2 emission index, necessitating a multiobjective optimization approach.
• The system was optimized using artificial neural networks and particle swarm optimization, resulting in a 17.8% enhancement in ERTE and a 14.8% decrease in emissions relative to the base design.
• The optimized system achieved an annual CO2 emission index of 23 kg/MWh, significantly lower than the regional grid average of 555 kg/MWh.
• A year-long climatic assessment of Shanghai revealed significant seasonal adaptability, with the levelized cost of energy decreasing to 35.9 USD/MWh and CO2 emissions remaining consistently below 25 kg/MWh during the summer months.
• The research concluded that the proposed system's technical, economic, and environmental feasibility as a power-to-X solution, providing a scalable approach for clean energy generation and hydrogen storage in solar-abundant urban settings.

Statistics:

• The hybrid system achieved a 35.9 USD/MWh levelized cost of energy in the optimized design.
• The system's annual CO2 emission index was 23 kg/MWh, significantly lower than the regional grid average of 555 kg/MWh.
• The optimized system resulted in a 14.8% decrease in emissions relative to the base design.
• The levelized cost of energy decreased to 35.9 USD/MWh during the summer months in the climatic assessment of Shanghai.
• The optimized system achieved a 17.8% enhancement in ERTE.

Sources:

• International Journal of Hydrogen Energy, 2025; 178.
• Pergamon-elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England.