“…Geothermal energy is a sustainable, clean, and renewable source of energy that has been studied extensively in recent years and showed great potential to be used as a direct-use energy supply [81][82][83][84]. Although a low-temperature resource, geothermal heat extraction and utilization have been widely investigated in HAP due to its low-cost and availability in many countries all over the world [85][86][87][88][89]. Geothermal energy can provide the required heat for large-scale SMS by means of ground source heat pumps either exclusively or in combination with other heat sources such as electric heaters or fuel boilers [90,91].…”