Portugal Mainland
Azores
In Portugal geohydrological studies
have increased considerably in the last two decades.
Some of the projects have already passed the feasibility
phase.
In the Portuguese mainland, there
are about fifty natural low enthalpy geothermal
occurrences spread all over the country. Temperatures
range from 20°C to 76°C, however, most of these
occurrences have temperatures between 20°C and 40°C.
Their geographical distribution is not uniform throughout
the country. The most important geothermal occurrences
are located in the northern part of Portuguese mainland.
Most of the thermal waters flow in
the Pre-Mesozoic Hesperic Massif associated with
granitic and schistose rocks and are related to
local and regional fault systems. The thermal occurrences
issuing in the Western and Southern Sedimentary
Borders display lower temperatures but have higher
water flows and total dissolved solids than those
from the Hesperic Massif (Carvalho, 1998).
In the Azores islands a large number
of active volcanic manifestations are well known,
justifying the considerable rise in geothermal investigations.
The program on São Miguel Island has resulted in
a pilot geothermal generator plant producing 20-25%
of the island requirement (Bicudo da Ponte, 1998).
Average temperature of the reservoir is 240ºC at
1200 m and the well-head temperature is about 200ºC
(Carvalho, 1998).
http://www.geothermie.de/egec_geothernet/menu/frameset.htm
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