Geothermal energy is the recovery of energy from the ground. The ground contains a significant quantity of energy which is permanently replenished, the majority of which comes from the sun's rays. The ground constitutes an inexhaustible reserve of heat which comes from its depths.
From the beginning of time, this energy has essentially been used in the form of hot water taken directly from underground springs.
In France, geothermal energy is not yet widely used but it is becoming more and more popular. Today it represents one of the primary sources of renewable energy in terms of energy produced.
This energy which is stored in the upper layers of the ground comes from underground water and is easily recoverable by water-to-water or glycoled water-to-water heat pumps.
Three techniques are available