Conventional Energy Sources in India: Coal, Petroleum, Natural Gas

In India, coal, petroleum, natural gas, and electricity are the main sources of energy. Coal, formed from plant material over millions of years, dominates energy production, followed by petroleum and natural gas. These conventional sources play a crucial role in powering industries and meeting domestic needs.”

Conventional Energy Sources

A. Coal

• • Coal occurs in rock sequences mainly of two geological ages, namely Gondwana and tertiary deposits. About 80 per cent of the coal deposits in India is of bituminous type and is of non-coking grade.

• Coal Types and Classification

• • • Gondwana Coal (Metallurgical): Over 200 million years old; found in Damodar Valley (Jharkhand-Bengal).
    • Tertiary Coal: 55 million years old; in northeastern states and Himalayan foothills.
    • Lignite: Low-grade brown coal with high moisture; used for electricity generation; prominent in Neyveli, Tamil Nadu.

• Distribution in India

• Gondwana Coal Fields: Located in Damodar Valley (Jharkhand-Bengal coal belt). Coal fields: Raniganj, Jharia, Bokaro, Giridih, Karanpura. 

• • • Other river valleys associated with coal are Godavari, Mahanadi and Sone. 

• Important Coal Mining Centres: 

• • Singrauli in Madhya Pradesh (part of Singrauli coal field lies in Uttar Pradesh); 
  • Korba in Chhattisgarh; Talcher and Rampur in Odisha; 
  • Chanda–Wardha, Kamptee and Bander in Maharashtra and 
  • Singareni in Telangana and Pandur in Andhra Pradesh.
• Tertiary Coals: Tertiary coals occur in Assam, Arunachal Pradesh, Meghalaya and Nagaland. 
  • It is extracted from Darangiri, Cherrapunji, Mewlong and Langrin (Meghalaya); 
  • Makum, Jaipur and Nazira in upper Assam, 
  • Namchik – Namphuk (Arunachal Pradesh) and Kalakot (Jammu and Kashmir).
• Lignite (Brown Coal) Areas: Coastal regions of Tamil Nadu, Pondicherry, Gujarat, Jammu and Kashmir. 
• Coal is classified into four main types based on amounts of carbon and amount of heat energy the coal can produce: anthracite, bituminous, subbituminous, and lignite.
  • Anthracite contains 86%–97% carbon
  • Bituminous coal contains 45%–86% carbon
  • Lignite contains 25%–35% carbon
• Rat Hole Mining: Involves digging small tunnels for coal extraction; Prevalent in Meghalaya.

B. Natural Gas 

• • Composition: Primarily methane (around 95%); also includes ethane, propane, butane, and pentane.

• • Formation: Organic matter (plants and animals) decomposes under high pressure and heat over millions of years.

• Distribution in India: Krishna Godavari Basin (KG Basin), Assam Shelf, Gulf of Cambay, Barmer Basin (Rajasthan), Tripura, Tamil Nadu coast, and offshore wells in Gujarat and Maharashtra

• Types 

• • • Associated gas (wet gas): Produced along with crude oil.
    • Non-associated gas (dry gas): Found in separate reservoirs.
    • Sour gas: Contains hydrogen sulfide, requiring additional processing. 
    • Sweet gas: Hydrogen sulfide-free, like coalbed methane.
  • Environmental benefits: Lower carbon dioxide emissions than coal or oil, making it a cleaner fossil fuel.

• Uses

• • Energy source: Power generation (15% of India’s electricity (as of December 2023), industrial boilers, heating homes.
  • Chemical feedstock: Used in fertilizers, plastics, and other products.
  • Transportation fuel: Compressed Natural Gas (CNG) for vehicles.

Petroleum and Mineral Oil (Liquid Gold)

• Crude petroleum occurs in sedimentary rocks of the tertiary period.  It is formed from ancient marine organisms buried in the ocean floor.
• Distribution of Petroleum and Mineral Oil in India: Major reserves associated with anticlines and fault traps in sedimentary rocks
• Regions: Mumbai High, Bassein, Aliabet; Assam (Digboi, Naharkatiya and Moran), Gujarat (Ankaleshwar, Kalol, Mehsana, Nawagam, Kosamba and Lunej); Krishna-Godavari and Kaveri basin on the east coast
• Petroleum Refining in India: Refining started in 1901 in Digboi, Assam. Two types of refineries in India: (a) Field based (Digboi)  (b) Market based (Barauni).
• Strategic Petroleum Reserve (SPR): India’s SPR facilities at Visakhapatnam (Andhra Pradesh), Mangalore, and Padur (Karnataka)are managed by ISPRL. Additional reserves planned for Chandikhole (Odisha) and Bikaner (Rajasthan).

Conclusion

India’s energy landscape heavily relies on conventional sources like coal, petroleum, and natural gas, alongside electricity generation. While these sources have fueled growth, there’s a growing recognition of the need for sustainable alternatives to meet future energy demands and mitigate environmental impacts.”