The combination of Geothermal System and Photovoltaic they can turn a building into an NZEB i.e. a building with almost zero energy consumption. It is worth noting that both systems are part of the RES (Renewable Energy Sources) family. But in a building these are used for a different purpose: The Photovoltaic installation has the role of the electricity producer (Producer) The Geothermal System has the role of the Heating/Cooling system (Consumer)  At this point you raise the reasonable question “Since the Geothermal system consumes energy why does it belong to the RES family?” The following tables give the answer to this question Geothermal systems can be applied in any climate for heating or cooling systems, whereas other options have restrictions as to the optimal climatic conditions (Tables 1 & 2). What is more, Geothermal Systems can perform much more efficiently than all other systems and the equipment has