The up-to-date heat pump–combined heat and power solution for the complete utilization of the low enthalpy geothermal water potential

The paper focuses on the thermal potential utilization of the geothermal resources from the Olt Valley (Romania, Calimanesti, Caciulata area). The three existing drills ensure low enthalpy geothermal water (92–95 °C) having, at the exit of the wells, a high content of combustible gases. The equivalent hot water thermal potential—without the use of the combustible gases—is used for heating several spa hotels and for the heat supply system of the urban area. At present, the gases from the geothermal water, having a rich content of methane (88 %), are released into the atmosphere. The paper proposes a solution concerning a complete valorisation of the energy potential of this geothermal water, using heat pumps and a high-performance micro gas turbine cogeneration unit. We highlight that it is possible to extend the exploitation of the geothermal energy by a viable solution, via which the investment can be recovered in a short time. This work provides a solution in total accordance with the frame of the European Directives regarding the increase in energy efficiency, the use of the renewable resources and the environment protection.