Thermal energy storage contribution in the combined heat and power-based integrated energy networks

Integrated energy networks require advanced flexibility solutions to address the variability of demand and renewable generation. Thermal energy storage (TES) is a key technology for enhancing the flexibility and reliability of combined heat and power (CHP)-based multienergy systems. This article presents a unified modeling framework for TES within CHP-based integrated energy networks, incorporating a detailed TES formulation into the coordinated optimal operation of electrical, natural gas, and district heating subnetworks. The proposed framework models its charging and discharging processes, operational coupling with CHP units and district heating temperature regulation. The results show that TES can significantly smooth fluctuations in CHP-generated electrical and heat power, maintaining a more stable supply to the subnetworks. TES units located at strategic nodes enable effective load shifting, improving the operational flexibility of CHPs and mitigating peak demands. A large-scale case study solved with the Teaching–Learning-Based Optimization algorithm demonstrates that these performance improvements are achieved with a marginal increase in total operational cost (from $121,270 to $121,700, ∼0.35%), while it provides substantial benefits in enhancing system flexibility. Beyond the case study, the proposed framework is generalizable across diverse network topologies and the findings demonstrate that TES integration in the CHP-based networks is a strategic investment for improving overall energy network performance while accommodating variable demand and generation conditions.