Geopressured resources
Geopressured geothermal
resources consist of hot brine saturated with methane, found
in large, deep aquifers under high pressure. The water and
methane is trapped in sedimentary formations at a depth
of about 3km-6km. The temperature of the water is in the
range of 90 °C - 200 °C. Three forms of energy can be obtained
from geopressured resources: thermal energy, hydraulic energy
from the high pressure and chemical energy from burning
the dissolved methane gas. The major region of geopressured
reservoirs discovered is in the northern Gulf of Mexico.
Hot Dry Rock
Hot dry rock (HDR) is a
heated geological formation shaped in the same way as hydrothermal
resources, but containing no water as the aquifers or fractures
required to conduct water to the surface are not present.
This resource is virtually limitless and is more accessible
than hydrothermal resources.
Magma
Magma, the largest geothermal
resource, is molten rock found at depths of 3km-10km and
deeper, and therefore not easily accessible. It has a temperature
which ranges between 700 - 1,200 ° C. The resource has not
yet been well explored.
Geothermal energy
utilization
Geothermal reservoirs are
generally classified as being either low temperature (under
150°C) or high temperature (over 150°C). It is the high
temperature reservoirs that are suitable for the commercial
production of electricity; while lower temperature fluids
provide hot water for space-heating purposes, heat for greenhouses
and the industrial sector, or they supply resort spas with
thermal water.
Geothermal
power plants for electricity generation are most often
constructed where hydrothermal energy appears in the form
of steam. More and more sites suitable for steam production
have been discovered, which has increased the number of
geothermal power plants, mainly in Iceland, Japan, USA,
New Zealand and Italy. Though there are not many sites
suitable for steam production in the world, plenty of
hot springs can be found at a temperature between 35-100
°C.
Geothermal Energy and Other Distinctive Energy
Sources
