India is a country with vast diversity in terms of geographical landforms and features. Our country is endowed with mineral wealth as also with hot and cold water springs.
Hot Water Springs In India
Thermal springs or hot water springs are formed due to geothermally heated water emerging onto the earth’s surface through cracks. This heat comes from deep inside the earth’s surface. In north India, Jammu and Kashmir, Uttarakhand, Himachal Pradesh and Haryana and western states such as Gujarat and Rajasthan contain multiple hot water springs. In eastern India, West Bengal, Sikkim, Arunachal Pradesh, Assam and Meghalaya are the states that house thermal springs. Southern states like Maharashtra, Odisha, Karnataka, Tamil Nadu, Andhra Pradesh and Kerala and central states like Bihar, Jharkhand and Madhya Pradesh also have geothermal springs. Andaman and Nicobar Islands also have multiple hot water springs. More than 340 hot spring locations have been identified by the Geological Survey of India (GSI) and these are mentioned in the Geothermal Atlas of India. This atlas is being updated on a regular basis.
These hot water springs may contain different kinds of minerals. The most common mineral that is present in the thermal springs of India is sulphur. India used to be a hotbed of active volcanoes millions of years ago. The remnants of those volcanoes today can be seen in the form of hot water springs that contain sulphur. The hot water springs of Rajasthan, Odisha, Karnataka, Arunachal Pradesh, Sikkim, Himachal Pradesh, Jammu and Kashmir and most of the other states also are rich insulphur. Other minerals may also be present in these springs in variable quantities. These include Helium, Nitrogen, Argon, Carbon Dioxide, Methane, Germanium, Boron, Copper, Chromium, Zinc, Oxygen, Lithium, Calcium, Alum, Hydrogen and even radioactive elements like Radium. Springs containing radioactive elements are present in Bihar, Gujarat, Mumbai and Himachal Pradesh. Chalybeate and sulphurous springs are most common in Himalayas. Hot water springs can also be saline, alkaline or rich in magnesium. For example, West Bengal houses only one hot water spring which contains Helium. The Manikaran springs contain high doses of Uranium and other radioactive elements. If the link between the geothermal heat and the water which has reached the surface is cut-off, the hot water spring becomes a normal or cold water spring. Many such coldwater or normal springs, which are now seen in the form of ponds or lakes, are found in India. One such sulphurous cold spring is located in Uttar Pradesh.
Many mythological beliefs and stories circulate around all the geothermal springs in India. That is why many places of worship have been built around them. These legends attract tourists as well as pilgrims to these areas. Apart from pious reasons, these hot water springs also have medicinal properties depending on the type of mineral they contain. The sulphur in these springs help in the treatment of skin infections like rashes, eczema, dermatitis, warts and dry scalp. It also helps to treat arthritic pain and menopausal symptoms. The heat of the water improves blood circulation, in turn reducing hypertension, nervous imbalances and arthrosclerosis.
Harnessing geothermal energy
Estimations from geological, geochemical, shallow geophysical and shallow drilling data have shown that India has a geothermal power potential of 10,000 MW or 10 GW. GSI began the exploration of geothermal springs in 1970. Chief geothermal provinces in India include Himalayas, Naga-Lushai province, Sohana, West coast, Andaman-Nicobar Islands, Cambay, Son-Narmada-Tapi (SONATA), Godavari and Mahanadi valleys. Of all the locations, Puga valley in Ladakh is the most promising. Ministry of New and Renewable Energy (MNRE) wants to achieve an installed capacity of 1000 MW till 2022 and 10 GW till 2030. This is part of the India’s plan to increase the share of power production to 350 GW by 2030 through renewable sources of energy India is planning to achieve this ambitious target in partnership with USA, Philippines, Mexico and New Zealand. These countries are top producers of geothermal power generation in the world.
The basic data of geothermal fields in India are summarized below indicating possible areas for development in India:
|S. No.||Geothermal Province||Locality||Temp. gradient (°C)||Heat flow (mW/m2)|
|1||Himalayan||i. Puga Chumthang, Ladakh||30 to 84||41 to 160|
|ii. Manikaran||34 to 96|
|iii. Tapoban||30 to 65|
|2||Son- Narmada-Tapi (SONATA)||i. Tatapani||52 to 97||70 to 300|
|ii. Anhoni-Samoni||32 to 45|
|3||West Coast||Maharashtra||62 to 72||130+|
|4||Mahanadi valley||Bakreshwar||40 to 70||200+|
|5||Godavari valley||Manuguru||36 to 44||80 t0 100|
|6||Naga-Lushai||i. Assam||46 to 52||Data unavailable|
|7||Andaman and Nicobar Islands||i. Barren Islands||Data unavailable||Data unavailable|
|ii. Narcondum Islands|
|8||Aravalli||i. Rajasthan||41+||100 to 125|
|10||South India||Isolated springs||Variable||Variable|
Geothermal energy is harnessed by drilling deep wells into underground reservoirs to tap steam and very hot water that drive turbines which in turn will drive electricity generators. Four types of power plants are operating today:
- Flashed steam plant
- Dry steam plant
- Binary power plant
- Hybrid power plant
Indian organisations that are trying to harness and use geothermal energy are Central Electricity Authority, Geological Survey of India, Indian Institute of Technology (Mumbai), Regional Research Laboratory of Jammu, National Geophysical Research Institute (Hyderabad) and Oil and Natural Gas Corporation (Dehradun). There are currently two ongoing projects in India, one at Tattapani geothermal area in central India and the other at Puga geothermal area in Ladakh region, Jammu & Kashmir. The exploration of other geothermal provinces is being planned and has begun at a few other locations. Only small-scale power generation through geothermal energy is being explored in India as of yet. In north India, this energy can also be used for domestic heating and growing crops through greenhouses while in south India, this energy can be used for non-electrical purposes as well.
In collaboration with Norway and Iceland, the Wadia Institute of Himalayan Geology is engaged in a project to use the hot water springs in Uttarakhand to generate electricity to provide heat to homes. Chumathang hot water spring in Ladakh region of Jammu and Kashmir had been chosen as the location to implement the pilot project. The water can be drawn into spas to promote geo-tourism and balneotherapy by diverting the water from such springs to a restaurant. It has also been used for central heating and greenhouse purposes. This project successfully improved the living conditions and livelihood of the local population.
The geothermal energy in India can be used for:
- Power generation
- Space heating
- Use in greenhouse cultivation
- Crop drying
The advantages of geothermal energy are:
- Reliable and stable source of energy
- Clean and environment friendly
- Abundantly available all over the country