Thermal Synergy (TS) for fifth-generation district heating and cooling (5GDHC) networks early-stage design and feasibility

The transition to sustainable urban environments necessitates innovative solutions in energy management, particularly within the building sector. Fifth-generation district heating-and-cooling (5GDHC) networks, which utilize water loops and decentralized water source heat pumps (WSHP), offer significant potential for decarbonizing the built environment and enhancing energy efficiency. These networks allow for efficient thermal exchange, renewables integration and waste heat recovery among connected buildings, thereby minimizing the reliance on external energy sources. However, the implementation of 5GDHC networks faces challenges, including significant initial investments and the lack of dedicated tools for detailed design.

This paper aims to optimize the integration of buildings within 5GDHC networks to maximize thermal energy exchange and minimize the requirement for backup energy sources. The proposed methodology assesses the compatibility of buildings based on their thermal demand profiles, with the goal of identifying configurations that enhance network thermal energy transfer.

This analysis introduces a “thermal synergy index” that quantifies the mismatch or alignment between the thermal profiles of buildings within the network. This index is used to estimate the potential energy performance of the network in urban areas, detecting promising neighborhoods suitable for 5GDHC. Thus, the thermal synergy index provides a predictive tool for assessing and optimizing energy efficiency during the design phase of these systems.

The paper presents the application of the method to the thermal demand profiles of prototypes buildings, which represent various usage categories and are recognized globally for benchmarking purposes. Sample neighborhoods with different thermal synergy indexes are then simulated with a 5GDHC numerical model to assess method’s relevance and reliability.

Preliminary findings suggest that the thermal synergy index effectively identifies optimal building pairings that enhance the 5GDHC networks performance. A percentage increase in the index values is indeed reflected in similar percentage energy savings in the balance of the entire network. The results show how a careful and planned coupling of specific users within the network can reduce the need for supplemental heating or cooling from external sources by 10 to 15%. The outcomes highlight the importance of detailed feasibility and design considerations in deploying 5GDHC systems, offering valuable insights for urban planners and energy policymakers.

This research improves the understanding and practical application of 5GDHC networks, providing essential tools for their design and optimization. Future work will focus on refining the thermal synergy index and exploring its application in diverse climatic and urban contexts, further advancing the feasibility and effectiveness of 5GDHC networks.