Geothermal energy in India

WHY IN NEWS:

• State-owned Oil and Natural Gas Corporation (ONGC) to implement India's maiden geothermal field development project in Ladakh

WHAT IS GEOTHERMAL ENERGY?

• Geothermal energy is the heat that comes from the sub-surface of the earth.
• It is contained in the rocks and fluids beneath the earth’s crust and can be found as far down to the earth’s hot molten rock, magma.
• To produce power from geothermal energy, wells are dug a mile deep into underground reservoirs to access the steam and hot water there, which can then be used to drive turbines connected to electricity generators

USE OF GEOTHERMAL ENERGY ACROSS THE WORLD:

• First used in Italy in 1904, geothermal has been a consistent – and expanding – source of energy in recent years.
• According to the International Renewable Energy Agency (IRENA), geothermal energy has grown steadily from around 10GW worldwide in 2010 to 13.3GW in 2018.
• Geothermal energy is used in over 20 countries.
• The United States is the largest producer of geothermal energy in the world, and hosts the largest geothermal field.
• Forty per cent of the world’s geothermal energy resources are located in Indonesia >> because with 130 active volcanoes, Indonesia is a hotbed of tectonic plate activity

GEOTHERMAL ENERGY IN INDIA

• India has seven geothermal provinces and more than 340 numbers of geothermal springs.
• Geothermal resources in India have been mapped by GSI and broad estimate suggests that there could be 10 gigawatt (GW) geothermal power potential, as per the Ministry of New and Renewable Energy (MNRE).
• Occurrence of the geothermal resources in India is mostly controlled by tectonic features.
• The main zone of geothermal resources is located in the Himalayas stretching from Puga in Jammu and Kashmir, Manikaran in Uttar Pradesh to Takshing in Arunachal Pradesh
• The development of geothermal resources in India was lagging behind due to non- availability of roper machinery and lack of incentive

GEOTHERMAL PROVINCES OF INDIA

MERITS OF GEOTHERMAL ENERGY

• Cleaner fuel:
  • Geothermal energy only produces one-sixth of the CO2 produced by a natural gas plant
• Renewable in nature:
  • The constant flow of heat from the Earth makes it inexhaustible and limitless.
• Uninterrupted supply
  • It is the only renewable energy available 24x7 to mankind not requiring storage and unaffected by day-night or seasonality variance.
• Alternative source of energy
  • Considering the need to reduce the coal based power by alternate sources of energy, it is pertinent to develop new energy sources like geothermal energy.
  • The geothermal energy can be used as main power source as well as substitute to electricity as a source of heat, depending on geothermal parameters and local geographical conditions
• Fulfill the need of remote locations:
  • It is a site-specific renewable source of energy, specifically suitable for catering to the energy needs of remote/interior localities.
• High efficiency:
  • Geothermal heat pump systems use 25% to 50% less electricity than conventional systems for heating or cooling, and require less space for hardware as opposed to conventional systems.
• By-products can be used
  • Mineral by-products from hot springs like silica, borax, cesium etc. may be exploited.

DEMERITS:

• Not so clean:
  • Despite low CO2 production geothermal has been associated with other emissions like sulphur dioxide and hydrogen sulphide.
• Affects the landscape
  • Similar to fracking, geothermal power plants have been the cause of mini tremors in the area they operate in
• Higher cost:
  • It has a high initial cost to build
• Location specific:
  • It is also described as “the most location-specific energy source known to man” due to its activity being along the tectonic plates of the earth’s crust.

SCOPE FOR DEVELOPMENT

• Power plant and direct heat uses:
  • The hot water upto 180°C can be used for electricity generation by binary cycle method.
  • The resources in remote areas and hilly terrain can be used for electricity generation to cater need of local population.
  • In India, the geothermal resources at Puga (Jammu and Kashmir), Tatapani Geothermal field (Chhattisgarh), Bakreshwar (West Bengal) is useful for binary cycle power generation.
• Refrigeration for preservation of fruits and vegetables
  • The effluent water from power plant can be utilized for refrigeration by evaporation in refrigeration plant of ammonia absorption type.
• Greenhouse:
  • Green house cultivation can be done by using hot water in cold weather conditions for growing vegetable and flowers in all seasons under controlled temperature and humidity.
  • Green house cultivation is possible in Manikaran, Tapoban, Parbati valley etc
• Snow melting:
  • The hot water can be used for snow melting and soil warming by circulation of water through subsurface pipes in places of extreme cold weather conditions like Puga-Chhumthang, Tapoban, Parbati valley, Manikaran
• Space heating:
  • The hot water can be used for maintaining warmth in houses during extreme cold weather in Himalayan belt
• Tourism, Spa, Swimming pool:
  • This is most popular use of geothermal water of low enthalpy almost in all geothermal localities.
• Coal washing:
  • Low temperature water is used for cleaning coal and separation of shale from mine
• Industrial uses:
  • Low to medium enthalpy hot water can be used for small scale industry
• Extraction of rare metals and extraction of helium
  • Extraction of dissolved heavy metals, rare gases and native elements like sulphur are noticed in geothermal areas.
  • It is profusely found in Puga, Tatapani etc.
  • Extraction of valuable minerals or metals from the geothermal processes help in bringing down the cost of geothermal power and makes it more attractive

STEPS TAKEN TO PROMOTE GEOTHERMAL ENERGY

• Draft National Policy on Geo-Thermal Energy
  • The vision of the scheme is to establish India as a global leader in Geo-thermal power by deployment of Geo-thermal energy capacity of 1000 MWth in the initial phase till 2022.
  • The scheme is to focus on assess the potential of geothermal resources in the country and promoting RDD&D projects of Power production and Geo-exchange Pumps
• Indian geo-thermal energy development framework
  • India proposes to harness 1,000 MW of geothermal energy till 2022 and 10,000 MW by 2030.
  • It envisages to make a substantial contribution to India’s long-term energy supply and reduce our national greenhouse gas emissions by developing a sustainable, safe, secure, socially and environmentally responsible geothermal energy industry
  • It aims to encourage the International Collaboration with the world leaders in Geothermal Energy like USA, Philippines, Indonesia, Mexico and New Zealand for support to accelerate deployment of geothermal energy by international investment promotion (100% FDI in RE Sector), Customized capacity building and technical assistance

WAY FORWARD:

• Financial incentive:
  • Geothermal exploration is a capital intensive activity, hence, financial incentives may be announced to promote exploration for geothermal resources.
  • Funding at exploration stage will motivate exploration agencies to take up geothermal energy projects for power generation and direct heat uses.
• Attract private parties for development of geothermal energy
  • Foreign funding and technology transfer may be encouraged along with suitable financial incentives to attract private parties for development of geothermal energy in India
• Need of more data:
  • The investigation carried out so far in India is mostly at shallow level creating a gap of data for planning power project.
  • It is significant to decipher characters of deep reservoir which will be useful to assess feasibility of the resources for power production

PRACTICE QUESTION:

Q. Analyze the prospects and challenges of geothermal energy projects in India