Low temperature geothermal systems

In low temperature geothermal systems, where temperatures are below 140° C, direct production of electricity from vapour is not generally convenient. However, if temperatures are above 90° C it is possible to use warm fluids to vaporise a second fluid that has a lower boiling temperature (such as freon, isobuthane or ethyl cloride), thus obtaining vapour for indirect electricity production, even if the productivity level of this process is rather low.
Hot waters though lend themselves to a variety of uses, with a “cascade” scheme, that first uses hot fluids in applications that require higher temperatures, and then reuse them, in applications that require lower temperatures, as they get cooler.
Its primary application is for urban heating, for which water between 130° C and 50° C can be used. Hot water fields are used for domestic heating in various states around the world, especially, in order of importance, in Japan, China, Hungary, ex- URSS, Iceland, Poland, France. The first experiments of geothermal heating for domestic usage took place in Iceland in 1930: in this country, a significant part of the capital’s houses heating comes from low-energy geothermal fields. In Italy this method is applied, for example, to hotels in the thermal area around Abano Terme (Colli Euganei, Veneto) and many buildings around Larderello (Tuscany).

Special reports

From the Multimedia section

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    Diagram of a geothermal power plant

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    Installed power of geothermal plants in Italy

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    Number of geothermal power plants in Italy

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    Geyser in Yellowstone Park

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    energy

    Energy of Earth

    Look
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    Temperature and depth

    Look

    energy

    Geothermal power plant

    Look
  • energy

    Spas

    Look

    energy

    Japanese macaques

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  • energy

    Geyser in Yellowstone Park

    Look
  • energy

    Energy of Earth

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    Temperature and depth

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Facts

  • 16 May 2011

    An artificial geyser

    Electric and thermal power produced from geothermal energy depend on the existence of underground infiltrations...

    Hydrogen from biomass

    Hydrogen is an energy carrier that allows to generate energy in an environmentally sustainable way...

  • Porto Marghera Hydrogen Park

    In Porto Marghera (Venice), the Hydrogen Park was created. It is the biggest centre in the world for hydrogen production...

    Hydrogen from the sugar cane

    The Centro di Ricerca Interuniversitario per lo Sviluppo Sostenibile (CIRPS) carried out a study in Peru...

  • 14 June 2011

    Some curiosities about methane hydrates

    The melting of the ice cells, not only brings about the release of methane gas, but it also produces another…

    16 May 2011

    The “wave-swallowing” dragon

    Wave Dragon, that swallows waves and generates electricity is a plant...

  • An artificial geyser

    Electric and thermal power produced from geothermal energy depend on the existence of underground infiltrations...

  • Hydrogen from biomass

    Hydrogen is an energy carrier that allows to generate energy in an environmentally sustainable way...

  • Porto Marghera Hydrogen Park

    In Porto Marghera (Venice), the Hydrogen Park was created. It is the biggest centre in the world for hydrogen production...