Volume 46: Energy Transitions toward Carbon Neutrality: Part IX

Analysis on the Long-term Performance of a Large-scale Seasonal Borehole Thermal Energy Storage System Fang Guo, Pengchao Li, Lili An, Xudong Yang

Abstract

To obtain a better understanding of the characteristics of large-scale seasonal borehole thermal energy storage (BTES), a demonstration project was developed in Chifeng, China. In the project, combined heat sources of industrial waste heat and solar energy were adopted for 500000 m3 borehole thermal energy storage. In this study, the long-term thermal and economic performance of the demonstration project was analyzed based on the operation data of the demonstration project. First, actual system energy and economic performance of the demonstration project were analyzed. After that, a system simulation model was established and calibrated with the long-term system measured data from the demonstration project. The system simulation model was integrated into the LCCA model for assessing system long-term economic performance with different system design parameters and operation strategies. Then a multi-object optimization based on Non-dominated Sorting Genetic Algorithm II (NSGA-II) was conducted for finding the optimal design configuration and system performance.
The results of this study showed that, the annualized cost of borehole thermal energy storage of the studied system around 4-6 US$/GJ, and it could be further reduced to 2.7 $/GJ in China by reducing the borehole drilling cost and returning water temperature of the district heating network. Which emphasized that borehole thermal energy storage has a good application prospect in future urban distributed energy systems.

Keywords borehole thermal energy storage, BTES, industrial waste heat, solar energy, district heating