Geothermal energy: energy from the depths of the earth

A local and sustainable resource, geothermal energy produces heat, cold and electricity. Here are five things to deepen your knowledge of geothermal energy, a valuable resource from deep within the earth.

1. Production of heat, refrigeration and electricity: geothermal energy does it all!

Indeed, geothermal energy is not limited to the heating of buildings! It harnesses the energy in the ground to provide heat… and cold too. In summer, underground cool can help lower building temperatures more virtuously than traditional air conditioning systems, which tend to be energy-hungry. The heat from the ground can also be transformed into electricity, as is the case in Iceland, Italy, and the overseas departments and regions. The goal? High temperature water is collected from great depths and turned into steam as it rises to the surface. The steam is then used to turn a turbine to power an alternator which produces alternating current. Geologically, 100% of French territory lends itself to at least one type of geothermal technology that could be used for multiple purposes.

>> Learn more about the uses and benefits of geothermal energy

2. Geothermal energy is super ecological!

By nature, geothermal resources are available 24/7, regardless of weather and seasonal conditions. They are capable of supplying freshness or renewable heat directly, without releasing heat into the atmosphere, and can even provide thermal energy storage throughout the year. Local, transport and carbon-free, inexhaustible energy! For example, it is used on the ENGIE campus, the Group’s future head office.

3. Geothermal energy, local energy

This energy is particularly interesting when it is used locally: the establishment of plants near natural water reservoirs makes it possible to avoid transport over long distances and, in doing so, to better conserve and use its heat. Geothermal energy is available everywhere in different forms, drilling from several meters to two kilometers deep. Likewise, if the depth and the multitude of geothermal drilling have an impact on the initial investment, this renewable energy has the lowest long-term cost, since the installations have low maintenance costs.

>> Discover a city powered by geothermal energy

4. Innovation at the service of geothermal energy

Geothermal energy is a constantly evolving energy. More and more innovations are being explored, such as multi-drains geothermal drilling technology which is being developed for the first time in Europe by ENGIE. It makes it possible to penetrate a geothermal reservoir several times and gives plants the greatest capacity for energy production. Dubbed Solar Impulse, the innovation received the Ruggero Bertani European Geothermal Innovation Award 2021, awarded by the European Geothermal Energy Council (EGEC).

5. Geothermal energy is also found in our oceans

Hot surface water and cold seabed water are channeled to an onshore plant to produce heat or cool. This is the case of the Thassalia project, developed in Marseille. This innovative plant is the first in France and Europe to use the thermal energy of the seas to heat and air-condition buildings. In the future, 500,000 m² will be connected to it!

>> Find out more about geothermal energy