The thermal manifestations in this region
appear in the form of hot springs, travertine deposits and stained ground
located along the right bank of the Indus River and expands for about 700m 13.
The temperature of the hot springs is
between 30°C and 87°C with a discharge rate of 1.5 litres/sec 13. The collective discharge of all the springs of
this region is 200 litres/min 13.
Geochemical studies shows that thermal
fluid at a temperature of 150°C exists in this region 13. Six boreholes have
been dug up here with a depth of about 20-221m. The temperature of the flowing
wells was found out to be 109°C and the collective discharge of these 4 flowing
wells is around 50 tones/hour 13. The temperature gradient is high between 0.7°-2.5°C
/m13. The water in this region has a relatively higher pH level and sulphate
level compared to the waters at Puga 13.
The geothermal energy from this region was
successfully used for greenhouse cultivation and space heating by maintaining a
constant temperature between 20°C-25°C even when the outside temperature was as
low as -35°C/-40°C in winter 13.
This region is located 50km east of Kulu
at an altitude of 1700m and consists of mainly of foliated gneiss interrupted
by younger granite 13. The hot springs in this region are found in the Manikaran
quartzite (Devonian) beneath the Main Central Thrust 13. The granite found
are possible sources of heat for the hot springs.
The thermal manifestations of this regions
appear in the forms of hot springs at a distance of 1.25 km on the right bank
of the Parvati River and these have a temperature ranging between 34°C-96°C and
at a distance of 450 m to the left bank with a temperature ranging between 28°C-37°C
The resistivity of this region is between
30-100 ?m. The pH value of the water ranges between 7.5 and 8.1 and the water
is mainly of NaHCO3Cl and NaCaHCO3Cl type 13. The
thermal water at the sub-surface has a temperature of 120°±10°C 13.
9 boreholes have been dug up with a
maximum depth of 707m 13. The maximum discharge rate from a single spring is
around 7 litres/sec and the collective discharge from 8 boreholes is around 100
tones/hour and temperatures between 45°C to 96°C 13.
A 7.5 ton capacity cold storage plant
which is based on the NH4-absorption process has been set up 13. A
5 KW pilot power plant based on the binary cycle technology which uses
ISO-butane liquid was successfully set up for testing purposes 13. This
region can be used a tourist attraction by developing these hot springs for
baths, spas etc. as these waters are free from corrosion 13.
This region is located in the Dhauli river
valley which is a major tributary to the Alaknanda River at an altitude of
1800m 13. There are a total of 5 hot springs in this regions that stretch
over 1 km along the hill slopes located on the left bank of the Dhauli river
shown in Figure 9 13.
The maximum temperature that was found is
65°C and the discharge rate from the springs ranges between 0.83-9.22
litres/sec 13. Geophysical assessments indicate that the region has a low
resistivity of about 100?m at depths of about 165m 13. The water is mainly of
Ca-Mg-HCO3 type with only one spring having gaseous secretions
having a breakdown of 78.6% CO2, 18.96% N2 and 2.4% O2
Figure 9 – Hot
spring along the hill slope
4 boreholes have been dug up in this
region with a depth between 291m and 728m and the collective discharge rate of
these boreholes was found to be 150 tones/hours with a high temperature
measuring 92°C 13.
Himalayan Region – Northeast
region consists of hot springs that are found in Sikkim 13. There are 5 hot
springs found at Yumthang, Yumesamdong, Borong, Polot and Rishi which are
scattered in the North, South and West parts of Sikkim 13. The temperature of
the springs are between 38°C-59°C with modest discharge rate 13. The water
from this region is only viable for direct uses such as bathing and drinking
and not as a non-conventional source of energy 13. The medicinal properties
of the water is due to the occurence of sulphur and boron 13.
following are the non-orogenic regions:
Cambay graben geothermal province 13
Son-Narmada-Tapi graben geothermal
West Coast geothermal province 13
Damodar valley geothermal province 13
Mahanadi valley geothermal province 13
Godavari valley geothermal province 13
North Indian Peninsular geothermal
Indian geothermal province 13
South Indian geothermal province 13
following are the important regions:
region is located about 100 km northeast of Ambikapur which is in Chhattisgar
and is said to be the most capable geothermal region in the Peninsular India 13.
thermal manifestations of this region is extremely intense in an area of 0.05
km2 consisting of mainly hot spouts, hot water pools and marshy land
as shown in Figure 10 13. The temperature of the water ranges between 50°C to
98°C and the collective discharge rate of the springs is around 60 litres/min 13.
water consists of two types: Ca-Mg-HCO3 and Na-HCO3-Cl-SO4
13. The sub-surface temperature was recorded to be around 120°C -150°C. 26
boreholes have been dug up with depths between 100m-620m 13. Blow out
conditions took place in 5 of these boreholes 13. The shut-in temperature of
the thermal fluid was found to be 112°C and the collective discharge rate from
the wells is 1600 litres/min 13.
on this discharge rate from the five holes and the temperature of the water, a
binary cycle power plant of 300 kWe is being considered and the use of this
power is for non-electrical purposes due to the remote nature of the area. Some
uses include: coccon boiling for extracting silk thread, cold storage, food
processing, spacing heating during winter, etc. 13.
West Coast Hot Spring Belt
are 60 thermal water springs located in 18 regions in this belt. The belt stretches
along the West Coast covering a distance of 350km from Koknere (north of
Mumbai) to Rajapur having an average width of about 20km (50km is the maximum
width in the north while 10-15km is the minimum width in the south) 13.
are 3 sub-regions consisting of hot springs as follows:
Northern region – 6 hot springs at
Koknere, Paduspada, Haloli, Sativli, Ganeshpuri and Akloli 13.
Central region – 4 hot springs at Sov,
Vadavli, Pali and Unahvre (Tamhane)
Southern region – 8 hot springs at Khed,
Unhavre (Khed), Aravli, Tural, Rajwadi, Sangameshwar, Math and Rajapur 13.
The waters in all the regions except for Rajapur
are of alkali chloride type while the water in Rajapur is of bicarbonate type. 12
boreholes have been dug up with a depth between 50m-500m in the west coast
regions 13. These include the 4 at Ganeshpuri-Akloli, 6 at Unhavre (Khed),
and 2 at Tural and Rajwadi 13.
uses of geothermal energy such as saunas, greenhouse cultivation for vegetable
production, cooking, poultry farming etc. and producing electricity, not only
reduces the usage of fossil fuels but also help grow the country’s economy 14.
Between the 3 types of geothermal power plant, the binary cycle power plant
works best for India because of its medium to low enthalpy regions (between
100°C – 150°C or less than 100°C) 14. Based on all these above locations of
geothermal energy, it is evident that India has great potential at building the
required facilities to harness the geothermal energy at these locations.
Ground Source Heat Pumps (GSHP)
is an enormous deficit between the demand and supply despite the increase in
capacity in power generation 10. The national average gap between demand and
supply during the peak hours is about 22% 10. This is expected to grow even
more due to the estimated economy growth of 6-8% per year, rapid urbanization
and improving living standards for Indian households 10. Increasing the
generation capacity alone will not be able to meet the high growth rate of the
demand. Demand side management (DSM) can be achieved by using Ground Source
Heat Pumps 10.
heating efficiency of this system is between 50%-70% compared to traditional
heating systems, and its cooling efficiency is between 40%-50% compared to
traditional air conditioners 14. It is also 100% water efficient since the
heat is rejected by means of conduction, convection and advection as compared
to the traditional evaporation of water in traditional A.C system resulting in
an estimated loss of 6-8 litres of water per hour for every ton of
air-conditioning used 10. The maintenance required for this system is quite
low (maintenance cost of about Rs 0.2/KWh) and these pumps can last over 40
years which compared to a combustion boiler (about 15 years). Only periodic
checks and filter changes are required 14. The heat exchanger can last over
50 years 14. The system can be used as a source of heat/cooling depending on
the season 14. There are 2 types of GSHP that are currently used around the
loop (earth-couple) system that utilizes closed pipes/tubes that are placed either
vertically or horizontally as shown in Figure 11 14. The water or a
combination of water and an antifreeze agent circulates resulting in the
transfer of heat to and from the earth 14.