Update on geothermal: Geothermal comes out of the darkness; Surface geothermal: how much does it cost? How much does it yield? Geothermal, to do what? In the residential, aero-thermal or geothermal? Renovation: the all-purpose drilling; Heating of swimming pools by the underground; Geothermal piles in college, history of a counter-example; Geothermal to heat greenhouses; Wine tempered by the ground; Geothermal for not a penny; Geothermal cold and cold networks; Geothermal cold in Ehpad; Tempered water loop, to reinvent tepid water; Tempered water in the countryside; Drillings and ground deformations, some human errors; Geothermal heat networks, an under-exploited potential; Deep geothermal for the industry

A set of article addresses various aspects of the different types of geothermal energy which still represents a very small share of the French energy mix: ambitions expressed in a recent action plan presented by the ministry for energy transition, cost and yield of surface geothermal energy (investments, supports and delay of return on investment for individuals, collective installations, and tertiary installations), geothermal installations for the residential sector and for public buildings (collector types) and for heat networks (with heat pumps, on probe field, for industrial or agricultural use, loop of geothermal tempered water), geothermal installations on waters (on surface water with opened or closed circuit, on waste waters, on sea water), deep geothermal installations (for electric power production, for electricity and heat production), choice between aero-thermal and geothermal for housing, possibility of drilling in any situation in the case of renovation, geothermal solutions for swimming pool heating, the failure of an example of geothermal piles in a college building, the use of geothermal energy to heat greenhouses, the use of geothermal energy to cool or to warm wine tanks, the use of third-party investment to pay only a rent for renewable energy, the benefits of geothermal hot and cold networks for buildings, the use of geothermal cold in long-term care homes, the use of a tempered water loop to supply low temperature networks, the use of tempered water in the countryside, human errors resulting in ground deformations when performing drillings, the under-exploited potential of geothermal heat networks, the use of deep geothermal energy by the industry. For many of these issues, some key data are provided