Optimizing for clean-heating improvements in a district energy system with high penetration of wind power

Strong interdependence of heat and power generation makes most existing power grids in northern China unfriendly to wind energy. However, wind energy has increased significantly in the past 15 years. Furthermore, most areas in northern China suffer from severe air pollution in winter, which is caused by the substandard emissions from coal-fired heat generators. Therefore, introducing power-to-heat devices and thermal energy storage (TES) system to the existing district energy system (DES) is an effective way to improve wind power integration, reduce operating costs, and bring considerable economic benefits. In order to determine the optimal configurations of additional power-to-heat devices and TES system, a novel two-layer economic optimization model has been proposed. In the outer layer of such model, the annual net profit (ANP) of each clean-heating project is calculated by introducing a traditional economic dispatch model. Regarding the outer layer, the solution space of varied clean-heating schemes is searched globally by the Genetic Algorithms. Results show that both introducing power-to-heat devices and TES equipment possess the highest economic potential. From the economical aspect, it is not necessary to integrate all available wind energy; thus, wind curtailments still exist after conducting the optimal clean-heating improvements.