A hybrid geothermal heat pump system has some advantages over a full ground-coupled heat pump system. Hybrid systems can reduce the first cost of a geothermal installation since the closed-loop fluid cooler capacity is less expensive than the same heat rejection capacity in a closed-loop ground-coupled grid. Additionally, a hybrid system typically is designed to meet a building’s peak heating load with the ground-coupled loop heat extraction peak requirements. This eliminates a supplemental heat-source boiler from the system. The advantage of a low pumping energy, closed-loop system also is attainable with the hybrid system using a fluid cooler.