Geothermal Systems are divided in several categories. The cases that have commercial interest are geothermal systems of low enthalpy.  Specifically, these systems could exploit in low cost the geothermal energy in every location, without to be demanded any specific conditions of pressure and temperature.

Exploitation of geothermal energy could be undertaken with several systems. The most efficient system is the open loop, where water is pumped strictly from the underground water reservoirs and then injected back through drilling wells.  The conditions that must be taken under consideration before this type be implemented is the quality and the quantity of the underground water’s reservoir.

The best compilation of Coefficient of Performance and reliability is the geothermal systems of vertical closed loop. More specific, wells are constructed with the smallest diameter that possible could have, so the minimum territorial disorder to be achieved. Additionally, after the 100 m drilling, pipes with very high durability are installed. The final stage is the filling of the borehole with specific mixture of high thermal conductivity or even better with the same soil that was extracted during drilling if that is possible.