Relevance:

• GS 3 II Economy II Infrastructure II Power and Energy

Why in the news?

The Oil and Natural Gas Corporation, announced that it will establish India’s first geothermal field development project in Ladakh. It will use the heat generated by the Earth’s core to generate clean energy.

Present context:

• India’s first geothermal field development project in Ladakh.
• The company informed that a Memorandum of Understanding was inked between ONGC Energy Centre and the Union Territory of Ladakh and Ladakh Autonomous Hill Development Council

Origin of geothermal energy:

• Geothermal energy is generated in the earth‘s core, almost 4,000 miles beneath the earth‘s surface.
• The double-layered core is made up of very hot magma (melted rock) surrounding a solid iron center. Very high temperatures are continuously produced inside the earth by the slow decay of radioactive particles.
• This process is natural in all rocks. Surrounding the  outer  core  is  the  mantle, which  is  about  1,800  miles  thick  and  made  of  magma  and rock.
• The outermost layer of the earth, the land that forms the continents and ocean floors, is called the crust. The crust is 3–5 miles thick under the oceans and 15–35 miles thick on the continents.

Indian Geothermal Resources:

• Physiographically, India is divisible into three distinct geographical units viz. the Extra- Peninsular Region, Indo-Gangetic Plain and the Peninsular Region.
• A variety of rocks ranging in age from Archaean to Holocene are exposed in these geographical units. The thermal springs have been classified on the basis of their occurrence in specific geotectonic setups and have been grouped under different Geothermal Provinces.
• The geological and structural criteria that have been used in the identification of the prospective Geothermal Provinces are:
  • Occurrence in an orogenic belt, which has undergone Cenozoic folding and upliftment
  • Occurrence in structural depressions/grabens, associated with late Tertiary and Quaternary upliftment in non- orogenic belts
  • Related to deep fault zones associated with recent seismicity
  • Occurrence in the areas of Tertiary or Quaternary volcanic activity

Global Scenario:

• Geothermal energy supplies more than 10,715 MW to 24 countries worldwide which is expected to generate 67,246 GWh of electricity
• An additional 28 gigawatts of direct geothermal heating capacity is installed for district heating, space heating, industrial processes, desalination and agricultural applications. This renewable energy source also has the potential to provide significant opportunities to do businesses both small and large.
• It is considered possible to produce up to 8.3% of the total world electricity with geothermal resources, serving 17% of the world population.
• According to market studies, investment in geothermal energy is growing globally at 24% a year. This exceptional investing growth rate is expected to continue – and increase even faster – for the foreseeable future.
• The largest group of geothermal power plants in the world is located at The Geysers, a geothermal field in California.
• The Philippines is the second highest producer, with1,904 MW of capacity online. Geothermal power makes up approximately 18% of the country’s electricity generation. Also in Indonesia 5% of overall electricity generation is from geothermal energy.
• Geothermal electric plants were traditionally built exclusively on the edges of tectonic plates where high temperature geothermal resources are available near the surface. The development of binary cycle power plants and improvements in drilling and extraction technology enable enhanced geothermal systems over a much greater geographical range.

Indian Scenario:

• India has reasonably good potential for geothermal; the potential geothermal provinces can produce 10,600 MW of power.
• Though India has been one of the earliest countries to begin geothermal projects way back in the 1970s, but at present there are no operational geothermal plants in India. There is also no installed geothermal electricity generating capacity as of now and only direct uses (eg.Drying) have been detailed.
• Thermax, a capital goods manufacturer based in Pune, has entered an agreement with Icelandic firm Reykjavík Geothermal. Thermax is planning to set up a 3 MW pilot project in Puga Valley, Ladakh (Jammu & Kashmir). Reykjavík Geothermal will assist Thermax in exploration and drilling of the site.
• India’s Gujarat state is drafting a policy to promote geothermal energy
• An experimental geothermal power plant of 5 kW capacity has been set up at Manikaran in HP. A cold storage plant has also been constructed there to utilise the geothermal energy at 900C for preserving vegetables and fruits grown in that area.
• Some of the prominent places where a power plant can be established based on geothermal energy are Puga Valley and Chhumathang in Jammu and Kashmir, Manikaran in HP, Jalgaon in Maharashtra, Tapovan in Uttarakhand, Bakreshwar in WB, Tuwa in Gujarat and Tattapani in Chhatisgarh. MNRE is giving thrust on exploration and harnessing of India’s geothermal energy resources.

Advantages of geothermal energy:

• No pollution: The first  advantage  of  using  geothermal  heat  to  power  a  power  station  is  that,  unlike  most  power stations, a  geothermal  system does  not create any pollution.  It may once in a while release some gases from deep down inside the earth, that may be slightly harmful, but these can be contained quite easily. Geothermal power plants have sulphur-emissions rates that average only a few percent of those from fossil -fuel alternatives.
• Less expensive lands used: The cost of the  land  to build a geothermal power plant on,  is  usually  less expensive  than  if  you were planning  to  construct  an;  oil,  gas,  coal,  or  nuclear  power  The main reason for this is land space, as geothermal plants take up very little room, so you don’t need to purchase a larger area of land.
• No environmental bills or quotas: Another factor that comes  into  this is  that  because  geothermal  energy  is  very  clean,  you  may  receive  tax  cuts,  and/or  no environmental bills or quotas to comply with the countries carbon emission scheme (if they have one).
• No fuel is used to generate: the power, which in return, means the running costs for the plants are very low as there are no costs for purchasing, transporting, or cleaning up of fuels you may consider purchasing to generate the power.
• No financial over burden: The overall financial aspect of these plants is outstanding, you only need to provide power to the water pumps, which can be generated by the power plant itself anyway. Because they are modular, then can be transported conveniently to any site. Both baseline and peaking power can be generated.
• Construction time can be as little as 6 months for plants in the range 0.5 to 10 MW and as little as 2 years for clusters of plants totalling 250 MW or more.

Disadvantages of geothermal energy:

• High levels of acids and volatile chemicals: Fluids drawn from the deep earth carry a mixture of gases, notably carbon dioxide (CO2), hydrogen sulfide (H2S), methane (CH4) and ammonia (NH3). These pollutants contribute to global warming, acid rain, and noxious smells if released. Plants that experience high levels of acids and volatile chemicals are usually equipped with emission-control systems to reduce the exhaust.
• Environmental damage: In addition to dissolved gases, hot water from geothermal sources may hold in solution trace amounts of toxic chemicals such as mercury, arsenic, boron, and antimony. These chemicals precipitate as the water cools, and can cause environmental damage if released.
• Adversely affect land stability: Plant construction can adversely affect land stability. Subsidence has occurred in the Wairakei field in New Zealand and in Staufen in Breisgau, Germany. Enhanced geothermal systems can trigger earthquakes as part of hydraulic fracturing. The project in Basel, Switzerland was suspended because more than 10,000 seismic events measuring up to 3.4 on the Richter scale occurred over the first 6 days of water injection.

What are the opportunities to develop geothermal energy resources?

• Independent Power Projects involved in non-conventional energy sources, are showing keen interest in geothermal energy resources, thanks to the awareness brought by those organizations working in this field such as the IITs (Chandrasekharam, 1995) and the GSI.
• One-time investment and low maintenance cost, low area requirement, and incentives given by the govt. for non-conventional energy sector is attracting many IPPs in India.
• Even IPPs who are involved in solar Photovoltaic and solar thermal power business are frantically exploring partners to finance geothermal projects. For example, M/s Avin Energy Systems, who are involved in solar Photovoltaic and solar thermal prewar projects, are keen to develop geothermal projects in Gujarat and expand their activities to other states as well.
• Since all the thermal provinces are located in rural areas with excellent communication system, power projects as well geothermal based industries are going to reduce congestion in Urban areas and improve socio-economic status of the rural public.

Conclusion:

With escalating environmental problems with coal based project, non-participation of IPPs in hydro power projects, logistic and technical problems clouding other non-conventional energy projects, in future, India has to depend on clean, rural based, cheap energy sources and cannot ignore its 10,600 MW geothermal potential. With available advance technology, all the medium enthalpy resources can be developed to support binary power projects. Alternatively, foreign IPPs can participate in power projects under “Build-Own-Operate-Maintain” (BOOM) scheme. Commissioning of at least one geothermal based power project is going to change the entire future power scenario of India. What is need at present is a project to drill deep holes and initiate studies on reservoir modeling. Data on thermal gases is lacking till now.

Mains oriented question:

What the reason for power projects towards geo thermal power projects, what are its pros and cons? (200 words)