Such areas in Greece are the volcanic islands of the Aegean (Milos, Nisyros, Santorini, Lesvos, Samothraki, etc.), many areas in Macedonia and Thrace (Nigrita, Siderokastro, Neo Erasmio, Nea Kessani, Tychero Evrou, etc.) as well as the environs of all of the 56 hot springs in Greece.
The applications of geothermal energy vary according to their temperature and include:
Power generation(θ>90 °C)
Space heating (with radiators, θ>60 °C, fan-coils, θ>40 °C, floor heating systems, θ>25 °C)
Refrigeration and air conditioning (using absorption heat pumps, θ>60 °C, or with water cooled heat pumps, θ<30 °C)
Heating greenhouses and soil because plants grow more quickly and become bigger with heat (θ>25 °C), and also for protection from frost.
Aquaculture (θ>15 °C) because fish require a specific temperature togrow.
Industrial applications such as desalination of seawater (θ>60 °C), drying agricultural products, etc.
Thermal spas (θ = 25-40 °C)
Besides geothermal fields, with today’s technology, heat from rock at a shallow depth, as well as low temperature underground or surface water can be used for heating and air conditioning. This technology involves the use of a very long pipe with a small diameter buried in the ground, or in wells, where it acts as an underground heat exchanger, coupled with a water cooled heat pump which provides heating or cooling to a building. Geothermal heat pumps consume one quarter of the electricity consumed by an electrical resistor and 1/2 that of an air conditioner. If the cost of energy is calculated over the life cycle of the system, geothermal heat pumps cost less than a system which consumes oil or natural gas.
In the future, geothermal energy will be exploited using hot dry rock, which is found everywhere at depths between 3 and 5 kilometers, by artificial water circulation through it at a temperature of up to 150 °C.