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...
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...
-
18 January 2016
Ten years of oil demand
Eni has recently published the 14th edition of the 2015 World Oil and Gas Review...
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…
17 March 2020
Energy and renewable sources: what is the current status?
The unstoppable growth of renewable sources continues…
-
4 November 2009
Ecological house
At present, it is more and more difficult to assure the comfort standard...
-
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...
-
4 November 2009
Ecological house
At present, it is more and more difficult to assure the comfort standard...
-
13 May 2013
Small steps, great footprints
Have you ever wondered how much space is taken up by an apple or a steak?...
From the Multimedia section
Facts
-
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...
-
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…
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...
-
The photovoltaic train
In Italy the PVTRAIN project by Trenitalia (co-financed by the European Union) plans...
The plant of Almeria
In the Tabernas desert, 30 km north-east of the Andalusia town of Almeria (Spain)...
New photocatalytic compounds
The term "photocatalysis" refers to a phenomenon by which a substance alters the speed of a chemical reaction
-
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...