Optimization of Heating Systems for Small Towns in Coal-Resource-Based Cities under Low-Carbon Transition

Coal-resource-based cities serve as crucial energy supply bases in China. However, their small towns persistently face challenges of high-carbon and inefficient heating systems due to low heat load density, insufficient pipeline coverage, and poor long-distance heat transmission efficiency. This study takes a typical coal-resource-based city in Northwest China as a case study to conduct a comparative analysis of four heating solutions: coal-fired boiler heating, long-distance combined heat and power (CHP) transmission, photovoltaic (PV)-driven air-source heat pump systems, and wind-PV hybrid power generation integrated with seasonal thermal energy storage. The results demonstrate that traditional coal-fired boiler heating has the lowest cost (21.70 RMB/GJ) but generates substantial annual carbon emissions (212,400 tons). The CHP solution shows significantly higher costs (78.49 RMB/GJ) due to expensive pipeline investments (accounting for 59.5% of total costs). Among the two renewable energy solutions, the wind-PV hybrid system with thermal storage demonstrates optimal comprehensive performance, achieving zero carbon emissions with competitive unit heating costs (25.81 RMB/GJ) and initial investments (889 million RMB). This study concludes that wind-PV hybrid systems with thermal storage represent the optimal pathway for low-carbon heating transition in small towns of coal-resource-based cities, requiring supportive policies to facilitate large-scale implementation.