Solar-attribute-aware low-carbon scheduling of CSP-TES-based integrated energy systems with hydrogen and carbon-capture coupling

In integrated energy systems (IESs) based on concentrated solar power (CSP) with thermal energy storage (TES), recovered heat from hydrogen conversion and carbon dioxide (CO2) capture can improve thermal flexibility, but it also complicates the attribution of CSP generation because TES discharge may contain both solar-derived and non-solar heat. To address this gap, this study proposes a solar-attribute-aware low-carbon scheduling framework for CSP-TES-based IESs. TES is modeled as a multi-source thermal hub that receives solar heat, hydrogen-cycle recovered heat, and high-temperature heat recovered from electrolytic molten carbonate (EMC)-based electrochemical CO2 capture. A solar-thermal attribute state is embedded in the TES balance to track the solar-derived heat share during charging, storage loss, and discharge. This tracked share is used to quantify green-certificate-eligible CSP generation under coordinated carbon emission trading and green-certificate trading mechanisms. A 50 MW class renewable-rich IES in Northwest China is used for validation. Compared with the baseline, the integrated configuration reduces total operating cost and net CO2 emissions by 31.49% and 47.13%, respectively. The results indicate that the proposed framework improves CSP certificate accounting consistency while coordinating recovered heat utilization, hydrogen conversion, and EMC-based CO2 capture in low-carbon system operation.