Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Geothermal heating
Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low (around 20%) since the heat is mostly needed in the winter.
Geothermal energy originates from the heat retained within the Earth since the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. Most high temperature geothermal heat is harvested in regions close to tectonic plate boundaries where volcanic activity rises close to the surface of the Earth. In these areas, ground and groundwater can be found with temperatures higher than the target temperature of the application. However, even cold ground contains heat. Below 6 metres (20 ft), the undisturbed ground temperature is consistently at the mean annual air temperature, and this heat can be extracted with a ground source heat pump.
There are a wide variety of applications for cheap geothermal heat including heating of houses, greenhouses, bathing and swimming or industrial uses. Most applications use geothermal in the form of hot fluids between 50 °C (122 °F) and 150 °C (302 °F). The suitable temperature varies for the different applications. For direct use of geothermal heat, the temperature range for the agricultural sector lies between 25 °C (77 °F) and 90 °C (194 °F), for space heating lies between 50 °C (122 °F) to 100 °C (212 °F). Heat pipes extend the temperature range down to 5 °C (41 °F) as they extract and "amplify" the heat. Geothermal heat exceeding 150 °C (302 °F) is typically used for geothermal power generation.
In 2004 more than half of direct geothermal heat was used for space heating, and a third was used for spas. The remainder was used for a variety of industrial processes, desalination, domestic hot water, and agricultural applications. The cities of Reykjavík and Akureyri pipe hot water from geothermal plants under roads and pavements to melt snow. Geothermal desalination has been demonstrated.
Geothermal systems tend to benefit from economies of scale, so space heating power is often distributed to multiple buildings, sometimes whole communities. This technique, long practiced throughout the world in locations such as Reykjavík, Iceland; Boise, Idaho; and Klamath Falls, Oregon; is known as district heating.
In Europe alone 280 geothermal district heating plants were in operation in 2016 according to the European Geothermal Energy Council (EGEC) with a total capacity of approximately 4.9 GWth.
Some parts of the world, including substantial portions of the western USA, are underlain by relatively shallow geothermal resources. Similar conditions exist in Iceland, parts of Japan, and other geothermal hot spots around the world. In these areas, water or steam may be captured from natural hot springs and piped directly into radiators or heat exchangers. Alternatively, the heat may come from waste heat supplied by co-generation from a geothermal electrical plant or from deep wells into hot aquifers. Direct geothermal heating is far more efficient than geothermal electricity generation and has less demanding temperature requirements, so it is viable over a large geographical range. If the shallow ground is hot but dry, air or water may be circulated through earth tubes or downhole heat exchangers which act as heat exchangers with the ground.
Steam under pressure from deep geothermal resources is also used to generate electricity from geothermal power. The Iceland Deep Drilling Project struck a pocket of magma at 2,100m. A cemented steelcase was constructed in the hole with a perforation at the bottom close to the magma. The high temperatures and pressure of the magma steam were used to generate 36MW of electricity, making IDDP-1 the world's first magma-enhanced geothermal system.
Hub AI
Geothermal heating AI simulator
(@Geothermal heating_simulator)
Geothermal heating
Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low (around 20%) since the heat is mostly needed in the winter.
Geothermal energy originates from the heat retained within the Earth since the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. Most high temperature geothermal heat is harvested in regions close to tectonic plate boundaries where volcanic activity rises close to the surface of the Earth. In these areas, ground and groundwater can be found with temperatures higher than the target temperature of the application. However, even cold ground contains heat. Below 6 metres (20 ft), the undisturbed ground temperature is consistently at the mean annual air temperature, and this heat can be extracted with a ground source heat pump.
There are a wide variety of applications for cheap geothermal heat including heating of houses, greenhouses, bathing and swimming or industrial uses. Most applications use geothermal in the form of hot fluids between 50 °C (122 °F) and 150 °C (302 °F). The suitable temperature varies for the different applications. For direct use of geothermal heat, the temperature range for the agricultural sector lies between 25 °C (77 °F) and 90 °C (194 °F), for space heating lies between 50 °C (122 °F) to 100 °C (212 °F). Heat pipes extend the temperature range down to 5 °C (41 °F) as they extract and "amplify" the heat. Geothermal heat exceeding 150 °C (302 °F) is typically used for geothermal power generation.
In 2004 more than half of direct geothermal heat was used for space heating, and a third was used for spas. The remainder was used for a variety of industrial processes, desalination, domestic hot water, and agricultural applications. The cities of Reykjavík and Akureyri pipe hot water from geothermal plants under roads and pavements to melt snow. Geothermal desalination has been demonstrated.
Geothermal systems tend to benefit from economies of scale, so space heating power is often distributed to multiple buildings, sometimes whole communities. This technique, long practiced throughout the world in locations such as Reykjavík, Iceland; Boise, Idaho; and Klamath Falls, Oregon; is known as district heating.
In Europe alone 280 geothermal district heating plants were in operation in 2016 according to the European Geothermal Energy Council (EGEC) with a total capacity of approximately 4.9 GWth.
Some parts of the world, including substantial portions of the western USA, are underlain by relatively shallow geothermal resources. Similar conditions exist in Iceland, parts of Japan, and other geothermal hot spots around the world. In these areas, water or steam may be captured from natural hot springs and piped directly into radiators or heat exchangers. Alternatively, the heat may come from waste heat supplied by co-generation from a geothermal electrical plant or from deep wells into hot aquifers. Direct geothermal heating is far more efficient than geothermal electricity generation and has less demanding temperature requirements, so it is viable over a large geographical range. If the shallow ground is hot but dry, air or water may be circulated through earth tubes or downhole heat exchangers which act as heat exchangers with the ground.
Steam under pressure from deep geothermal resources is also used to generate electricity from geothermal power. The Iceland Deep Drilling Project struck a pocket of magma at 2,100m. A cemented steelcase was constructed in the hole with a perforation at the bottom close to the magma. The high temperatures and pressure of the magma steam were used to generate 36MW of electricity, making IDDP-1 the world's first magma-enhanced geothermal system.