Some environmental and engineering problems are associated with permafrost thaw or degradation due to the releasing of CO2, the reducing of soil strength and the change of hydrologic processes. Flow to control the geothermal to approach these problems in cold regions is an important issue. Two-phase closed thermosyphons (TPCTs) are simple and efficient energy exchangers that are used in low temperature refrigeration systems. In this study, a series of experiments were carried out to explore the geotemperature control process of a TPCT in an air-TPCT-soil system by storing renewable ambient cool energy. To enhance the control efficiency of the TPCT, we considered different operating conditions, with inclination angles of 90 degrees, 70 degrees, and 50 degrees. The results indicate that the TPCT can cool the surrounding soil by selectively capturing the ambient energy due to its thermal semi-conductor effect. The inclination angle can change the efficiency of the TPCT, which should be accounted in engineering design. Under the experimental conditions, the geotemperature control efficiency of the TPCT with an inclination angle of approximately 70 degrees was the optimal. The results of this study could provide a basis for the design of TPCTs used in cool energy utilization and other energy storage applications. (C) 2018 Elsevier Ltd. All rights reserved.