Geothermal Condition Investigation and Resource Potential Evaluation of Shallow Geothermal Energy in the Yinchuan Area, Ningxia, China

Abstract

Shallow geothermal energy (SGE) is a promising green and sustainable energy source, gaining prominence in light of the dual-carbon target. This study investigated the SGE resources in the Yinchuan area. Suitability zones and the potential of SGE resources were determined based on the comprehensive analysis about thermophysical parameters, hydrogeological conditions, and geological environment. Our findings revealed that the effective thermal conductivity in the Yinchuan area surpasses those of other cities, indicating significant potential for SGE. The thermostat layer depth ranges from 40 to 60 m, with a geothermal gradient between 0.81 and 6.19 °C/100 m. Regions with poor adaptability for a borehole heat exchanger (BHE) are mainly distributed in the western and southern parts of the Yinchuan area, whereas moderately and highly adaptable areas are primarily located in the central and eastern areas, respectively. The total geothermal resource of the BHE in the Yinchuan area amounts to 1.07 × 108 GJ/a, generating significant economic benefits of 1.07 × 109 CNY/a and saving 1.09 × 106 t/a of standard coal annually. This initiative leads to significant reductions in CO2, SO2, and NOx emissions by 2.61 × 106 t/a, 1.86 × 104 t/a, and 6.57 × 103 t/a, respectively. Additionally, it results in potential savings of 0.309 × 109 CNY/a in environmental treatment costs. The methods and models used in this study have potential for similar geothermal surveys in arid and cold regions. The results also contribute essential insights for policy formulation and sustainable development strategies related to shallow geothermal resources in the Yinchuan area.