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Media center : Glossary

  • geosynchronous

    a geosynchronous orbit is 35,800 kilometers from earth on the equatorial plane. Orbiting at that level, a space device is considered to be stationary in relation to any point on earth from which it is visible. Satellites for telecommunications and global positioning systems (GPS) are in geosynchronous orbit. The sun shines on the solar collector continuously at that altitude, giving it the capacity for uninterrupted power generation.

  • geothermal couple

    assembly composed of a "rising" main well (through which ground water is pumped up) and a "descending" well at a distance from the main well through which water is reinjected. These couples are necessary when the geothermal hot water is not pure, to transfer heat from geothermal water to water in a secondary heating circuit without any mixing between the two circuits. Another advantage of the couple technique is that it maintains the pressure in the deposit, thus avoiding settlement of geological layers.

  • geothermal gradient

    recorded temperature increase for an increase in depth of 1 km. The average value of this gradient is about 33 °C, which is about 1 °C increase in temperature every 30 m. This temperature increase can easily be observed when going down into mines. In volcanic areas, the gradient can exceed 100 °C/km.

  • Glauber salts

    common name for hydrated sodium sulfate. Used for heat storage due to its low melting temperature.

  • Greenhouse Gases GHG

    greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluoro compounds (HFC), perfluoro compounds (PFC) and sulfur hexafluorides (SF6).

  • GT-MHR (Gas Turbine – Modular Helium Reactor)

    high temperature reactor using helium as a coolant.

  • GTL

    Gas-To-Liquids converted into a normal liquid hydrocarbon, GTL does not require a gas pipeline, and its ease of transport means that it can make a very real contribution to the economic development of remote regions. Compatible with today's engines, cars can use it directly as a fuel or a diesel additive. Seen as a market of the future, this new technology therefore presents an attractive alternative to liquefied gas in terms of cost.

  • Gtoe

    1 Gtoe equals 1,000,000,000 toe. One ton of oil equivalent (toe) corresponds to the quantity of energy obtained by burning one ton of oil.

  • Gy: GRAY

    the quantity of radiation absorbed by a body or an object exposed to radiation is measured in grays.

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True/False

Electric power plants using biomass do not release greenhouse gases