The Sun’s contribution

The subsoil does not only receive energy from the depths of the planet. The Sun’s energy warms the Earth’s surface and about 47% is directly absorbed by the soil: the temperature in the first metres of the subsoil are subjected to daily and seasonal variations according to the radiation received. These variations are more sensitive in the first decimetres or meters and weaken, until beneath about 20 m where the temperature is not affected by the external temperatures, but only by the geothermal gradient.
If there is the possibility of using even minor quantities of thermal energy, then the heat can also be obtained from this superficial layer: in this case, it is not the internal heat of the planet which is exploited but the energy provided indirectly by the Sun (so, in this case, the word “geothermics” is used incorrectly, but, as the same technology is used, usually this sector is included in the geothermal sources).

Special reports

  • 4 November 2009

    Ecological house

    At present, it is more and more difficult to assure the comfort standard...

    23 October 2013

    Carbon Footprint

    A very special footprint...

    13 May 2013

    Small steps, great footprints

    Have you ever wondered how much space is taken up by an apple or a steak?...

  • 18 May 2011

    Artificial photosynthesis

    The history of science and technology is packed with discoveries and inventions inspired by nature...

    27 September 2012

    Over 7 billion people on Earth

    Demographers have estimated that on 31 October 2011 world population...

    22 May 2016

    Green chemistry

    Chemistry accompanies man from that day long ago...

  • 18 January 2016

    Ten years of oil demand

    Eni has recently published the 14th edition of the 2015 World Oil and Gas Review...

    14 July 2021

    Italy’s renewable sources

    Renewable energy sources in Italy The Energy Services Operator (GSE) periodically publishes data and statistics on the renewable energy sources…

    10 September 2020

    A simple and ingenious invention

    There are objects so simple and ordinary that we forget their existence when we don't need them. Their presence is…

From the Multimedia section

  • energy

    Geothermal power plant

    Look

    energy

    Energy of Earth

    Look

    energy

    Geyser in Yellowstone Park

    Look
  • energy

    Spas

    Look

    energy

    Japanese macaques

    Look

    energy

    Temperature and depth

    Look
  • energy

    Installed power of geothermal plants in Italy

    Look

    energy

    Diagram of a geothermal power plant

    Look

    energy

    Geothermal energy production in Italy

    Look
  • energy

    Geothermal power plant

    Look

    energy

    Energy of Earth

    Look
  • energy

    Geyser in Yellowstone Park

    Look

    energy

    Spas

    Look
  • energy

    Japanese macaques

    Look

    energy

    Temperature and depth

    Look
  • energy

    Geothermal power plant

    Look
  • energy

    Energy of Earth

    Look
  • energy

    Geyser in Yellowstone Park

    Look

Facts

  • 16 May 2011

    An artificial geyser

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

    A hydrogen house

    In Settimo, a municipality close to Turin, the first Unité d’Abitation has been created...

  • Porto Marghera Hydrogen Park

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

    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...

    Bio-climatic architecture

    Solar energy is playing a vital role with reference to bioclimatic architecture...

  • An artificial geyser

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

  • A hydrogen house

    In Settimo, a municipality close to Turin, the first Unité d’Abitation has been created...

  • Porto Marghera Hydrogen Park

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