Performance analysis of operational strategies for monolithic receiver-reactor arrays in solar thermochemical hydrogen production plants

Solar thermochemical water splitting was successfully demonstrated with monolithic receiver-reactors in field at 50 kW scale. Since monolithic receiver-reactors are limited in size, several of the reactors will have to be combined in receiver-reactor arrays for large-scale plants. In this study, the yearly performance of solar thermochemical plants for hydrogen production implementing receiver-reactor arrays is investigated. Thereto, a transient receiver-reactor model is used in combination with realistic hourly flux profiles from dedicated MW high temperature solar concentrator systems. The batched operation of receiver-reactors leads to particular requirements of the array. Therefore, an array efficiency is introduced and different control strategies for the solar field are analyzed for performance optimization. Advanced strategies have the potential to substantially (~46%) improve the overall performance compared to the base case. Further design and operational optimization approaches are discussed, which allow approaching the theoretical array performance limit.