Geothermal energy represents one of the most feasible resources in green transition, while CLGS are a solution for the use of this type of energy, according to the Oil and Gas Employers’ Federation (FPPG). They explained, at a meeting with the press, that CLGS already used in Canada, Germany and USA, presents significant key advantages to conventional systems, among which the absence of fracture, the possibility of exploiting geothermal energy regardless of the availability of warm water sources in the vicinity of the cogeneration plant, the lack of risks of induced seismicity, the absence of any elements undergoing corosion, erosion, deposits and the direct connection between towns where there is demand and warm water resources. The closed circuit system supposes in depth drilling and introduction of pipes made of a special material in the soils in the vicinity of the magma rock layer, where there are temperatures of 300 degrees. Pipes are filled with water which will receive rock warmth. Water returns to the surface and reaches the cogeneration plant, where electric and thermal energies are produced. Romania is among the first five European countries with geothermal energy potential. 24 sites are being explored now and there are many underground sources of geothermal waters. FPPG experts pointed out that more locations in the west part of Romania, close to the border with Hungary, present adequate geological conditions for the development of geothermal projects and the application of heat systems in closed circuit. Several towns in Romania are already interested in the exploration and use of geothermal energy to heat residential areas: Arad, Timisoara and Oradea. The low number of very big drilling instalations needed for such works is a problem in the implementation of such projects, about 15 such installations being found in Europe. The initial cost of such installations is very high, at least million euros per loop, but later operational costs are very low. A series of legislative amendments are needed to use these geothermal resources, such as the amendment of the Mine Law recommended by FPPG representatives.