Concentrated Solar Energy with Thermal Energy Storage for Hydrogen Production by Three-Step Thermochemical Water-Splitting Cycles

The high-temperature thermochemical water splitting (TWS) cycles utilizing concentrated solar energy (CSE) and water are the most promising alternatives to produce renewable hydrogen. Here we couple CSE with thermal energy storage (TES) and TWS cycles to best levelize the cost of hydrogen by 2030, due to the synergies with concentrated solar power (CSP), the high technology-readiness-level (TRL) for the upstream thermal energy production and storage, and the medium TRL for the downstream TWS cycles. A similar design of the solar field and tower and TES for CSP advanced ultrasupercritical (AUSC) or supercritical CO 2 (sCO 2 ) power cycles for 100 MW of continuous production of electricity, permit the continuous production of hydrogen at ∼2,750 kg/h a day. The predicted cost is 1.058 to 1.197 $/kg H 2 by 2030.