Bulgarian Geothermal Association
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Geothermal energy in Bulgaria
Bulgarian
territory is rich in thermal water of temperature in the range of 20oC-100oC.
About 43% of the total flow rates are waters of temperature between 40oC-
60oC. The total dynamic flow rate of sub-thermal and thermal waters
runs up to 4600 l/s, (Petrov et.al.,1998). Ministry of Environment and
Waters is managing only state-owned thermal waters and their total discovered
resource estimated in March, 2009 was 1914,3 l/s. During the last five years
the exploitable part of it hasn’t significantly changed varying between 25 and
28%.
Direct
thermal water use nowadays is for balneology (prevention, treatment and
rehabilitation, bathing and swimming pools), space heating and
air-conditioning, greenhouses, geothermal ground source heat pumps (GSHP),
direct thermal water supply, bottling of potable water and soft drinks and for
some other processes. The cultivation of microalgae and production of iodine
paste and methane extraction have been terminated. Several applications -
balneology and geothermal ground source heat pumps show more stable development
at the present stage 2005-2010. At present, the update information concerns
mainly state-owned hydrothermal fields and is based on the existing permit and
concession regime.
Electricity
generation from geothermal water is not currently available in the country.
The highest
flow rate currently belongs to balneology (56%), followed by direct water
supply (19%) and space and greenhouse heating – totally 17%. In our analysis we
integrate all applications like prevention, treatment, rehabilitation, swimming
pools, sanitary needs, relaxation, drinking water out of taps only in one
category – balneology. Drinking water out of taps allows massive use for
disease prevention. Utilized water for relaxation and
sanitary needs has the highest share in balneology due to the existing
intensive hotels construction currently going on in the mountain and sea
resorts. The sites that are not registered according to the Law on Medical
Institutions and utilize thermal water for swimming pools, sanitary needs and
prevention get permits for relaxation. Direct supply with mineral water is
taking place in regions where no other alternative is available. This
application is typical for several resorts on the northern
.
Geothermal
activity is mainly concentrated in the southern part of the country due to the
higher water temperature there and low water salinity (TDS), mostly below 1g/l.
According
to the available information, geothermal energy for individual space heating
and air-conditioning is presently used in 11 state-owned reservoirs. It has decreased drastically during the period
2005-2010 and the total installed capacity was reduced to about 16 MWth. Heating installations are assisted by plate
heat exchangers. In addition they prepare domestic hot water and are in
operation for about 200 days/year. Some direct scheme systems still exist in
several sites, but they are of small capacity, in bad technical conditions and
are excluded from the estimation of total installed capacity, which amounts to
about 77,67 MWth (excl.GSHP). The produced energy is 1083.89 TJ/yr (towards
2009). .
The
approximate total area covered by geothermal greenhouses is about 6,5 ha (towards 2009) and the total installed
capacity reaches 6 MWt. Greenhouses are in operation in 7 sites and
produce mainly vegetables and flowers. This application has no current
development for the lack of investments, lost foreign markets and some land
ownership problems.
About 24
bottling plants using state-owned waters and 11, using municipality-owned
waters, are currently in operation. Their production meets mainly the demand of
the local market.
The use of
low-grade geothermal energy for seasonal heating and cooling has been
intensively developing. Application of geothermal ground source heat pumps
(GSHP) is carried out by private companies and very often is only one sector of
their activity. Open and closed loop systems
with vertical or horizontal collectors have been implemented. The inside
installations include under floor radiant heating or fan coils. Ground source
heat pumps are assembled in family houses, blocks of flats, hotels and
restaurants, office buildings, sport complex, auto-service and industrial
buildings in different regions of
Geothermal resource and potential
