Key Points
Key Points: Sources of Energy
- Meaning of Energy Resources: Energy is essential for all activities like heating, running machines and generating electricity.
- Types of Energy Resources: Energy resources are classified into renewable (can be used repeatedly) and non-renewable (get exhausted after continuous use).
- Conventional Sources of Energy: These are traditional sources used for a long time, such as coal, petroleum and natural gas. They are non-renewable, exhaustible and polluting. Hydel power is an exception.
- Non-Conventional Sources of Energy: These are renewable and inexhaustible sources like solar, wind, tidal, geothermal, nuclear and biogas energy.
- Importance for India: Energy resources play a crucial role in India’s economic development, and their proper and efficient use is very important.
Key Points: Conventional Sources of Energy > Coal
- Coal is the most important conventional energy source in India, formed from decomposed plant matter under heat and pressure over millions of years.
- Types of coal are Anthracite (best quality), Bituminous (most used), Lignite (brown coal) and Peat (lowest quality).
- Coal is mainly used for thermal electricity generation, iron and steel industry, industries and domestic fuel.
- Major coalfields are Jharia (largest), Raniganj (oldest), Talcher, Bokaro and Neyveli (lignite).
- Coal is cheap and reliable, but it is non-renewable, polluting and harmful to the environment and human health.
Key Points: Conventional Sources of Energy > Petroleum or Mineral Oil
- Petroleum (rock oil) is a fossil fuel made of hydrocarbons, found in sedimentary rocks. It is called “liquid gold” because every part of crude oil is useful.
- Petroleum products include petrol, diesel, kerosene, LPG, lubricating oil, paraffin wax, tar and bitumen, obtained after refining crude oil.
- It is widely used as fuel for transport, power generation, and as a raw material for petrochemical industries (plastics, synthetic fibres, rubber, paints, cosmetics).
- Major oilfields of India are Mumbai High (largest offshore field), Assam (Digboi – oldest), Gujarat (Ankleshwar, Kalol) and Krishna–Godavari basin.
- Petroleum has high calorific value and easy transport, but it is non-renewable, polluting, costly and causes oil spills and global warming.
Key Points: Oil Refineries in India
- Oil refineries are industrial plants where crude oil is processed into petrol, diesel, kerosene, LPG, lubricants, etc.
- India has many refineries located near coasts to reduce transport cost, as crude oil is largely imported from Gulf countries.
- Digboi Refinery (Assam, 1901) is the oldest oil refinery in India, while Jamnagar Refinery (Gujarat) is the largest refinery in the world.
- Important refinery states include Gujarat, Maharashtra, Assam, Tamil Nadu, Andhra Pradesh, Uttar Pradesh and Haryana.
- Most refineries are in the public sector (IOC, BPCL, HPCL), while some major ones like Jamnagar are in the private sector.
Key Points: Conventional Sources of Energy > Natural Gas
- Natural gas is a fossil fuel found along with petroleum and mainly consists of methane (about 95%).
- It is used in different forms such as LPG (cooking gas), CNG (vehicle fuel) and PNG (piped gas for homes).
- Mumbai High is the largest producer of natural gas in India; other producing areas include Assam, Gujarat, Andhra Pradesh, Rajasthan, Tripura and Tamil Nadu.
- Natural gas is a cleaner and eco-friendly fuel as it emits less carbon dioxide and leaves no solid residue.
- It is non-renewable, highly inflammable, and requires costly infrastructure for extraction, storage and transport.
Key Points: Conventional Sources of Energy > Hydel Power
- Hydel power is electricity generated from falling water, using dams, turbines and generators.
- It is a renewable and non-polluting source of energy and does not produce greenhouse gases.
- Hydel power projects are multi-purpose—they help in flood control, irrigation, navigation and water storage.
- India was an early developer of hydel power, with plants at Darjeeling (1898) and Shivanasamudra (1902).
- Although hydel power is cheap and sustainable, large dams are expensive to build and may cause displacement of people and environmental damage.
Key Points: Bhakra Nangal Dam
- Bhakra Nangal Project is a multipurpose river valley project built across the River Sutlej with two dams at Bhakra (Himachal Pradesh) and Nangal (Punjab).
- The Bhakra Dam reservoir, called Gobind Sagar, has a storage capacity of about 9.3 billion cubic metres.
- The project generates about 1,479 MW of hydroelectric power through power stations at Ganguwal, Kotla and Rupnagar.
- It provides irrigation to about 10 million acres of land in Punjab, Haryana and Rajasthan through the Bhakra canal system.
- The project helps in flood control, regulated water supply, and benefits Punjab, Haryana, Rajasthan, Himachal Pradesh, Delhi and Chandigarh.
Key Points: Hirakud Project
- Hirakud Dam is built across the River Mahanadi, about 15–21 km from Sambalpur in Odisha and is one of the first multipurpose projects after Independence.
- The Hirakud reservoir is the largest artificial lake in India, covering about 743 sq km; the dam is 61 m high and 4,801 m long.
- It provides irrigation through about 880 km of canals, irrigating nearly 10 lakh hectares in Odisha and Andhra Pradesh.
- The project generates about 270 MW of hydroelectric power from Hirakud and Chiplima power houses.
- It helps in flood control, navigation, and supports industrial development in mineral-rich regions; beneficiary states include Odisha, Chhattisgarh, Madhya Pradesh and Andhra Pradesh.
Key Points: Non-Conventional Sources > Solar Energy
- Non-conventional sources of energy are renewable, non-polluting and are considered the energy sources of the future as they help reduce global warming and dependence on fossil fuels.
- Solar energy is obtained from the Sun and converted into electricity using solar photovoltaic (PV) cells without using any moving machines.
- India has huge solar potential because of its tropical location, receiving about 300 sunny days a year; Rajasthan and Karnataka are leading solar power producers.
- Solar energy is widely used for electricity generation, water heating, cooking, lighting, irrigation pumps, crop drying and desalination of water.
- Advantages of solar energy include being renewable, pollution-free, low maintenance, easy installation, and helping conserve fossil fuels and reduce electricity costs.
Key Points: Non-Conventional Sources > Wind Energy
- Wind energy is a renewable, inexpensive and non-polluting source of energy used for generating electricity.
- Wind energy is generated using windmills; the force of wind rotates the blades, which turn a turbine connected to a generator to produce electricity.
- Windmills are installed in groups called wind farms, mainly in coastal areas, open plains and hilly regions where wind speed is high.
- India has great potential for wind energy and ranks among the top wind power producers in the world; Tamil Nadu (Nagercoil–Madurai belt) is the leading producer.
- Advantages of wind energy include no pollution, reduced dependence on fossil fuels, renewable nature, and additional income for landowners using wind turbines.
Key Points: Non-Conventional Sources > Tidal Energy
- Tidal energy is obtained from the regular rise and fall of ocean water caused by the gravitational pull of the moon and the sun.
- Electricity is generated using tidal barrages or floodgate dams; water enters during high tide and flows out during low tide, rotating turbines connected to generators.
- Tidal energy is renewable and predictable, as tides occur regularly in all seasons, even at night.
- It is a clean and non-polluting source of energy, producing no greenhouse gases or harmful residues.
- Major potential sites in India include the Gulf of Khambhat, Gulf of Kutch, Sundarbans, and the estuaries near Andaman–Nicobar and Lakshadweep Islands.
Key Points: Non-Conventional Sources > Geothermal Energy
- Geothermal energy is the heat energy obtained from hot rocks, steam and hot water present deep inside the Earth’s crust.
- Electricity is generated by drilling deep wells to bring hot water or steam to the surface, which rotates turbines connected to generators.
- It is a renewable, clean and environment-friendly source of energy, with very low emission of greenhouse gases.
- Geothermal energy works in all seasons and at night, as it is independent of weather and climate conditions.
- Major geothermal sites in India include Puga Valley (Ladakh), Manikaran (Himachal Pradesh), Tattapani (Chhattisgarh), Surajkund (Jharkhand) and Cambay Graben (Gujarat).
Key Points: Non-Conventional Sources > Nuclear Energy
- Nuclear power is generated from energy stored in the nuclei of atoms of radioactive elements like uranium, thorium and plutonium through a process called nuclear fission.
- During nuclear fission, heat is produced, which converts water into steam; the steam rotates turbines connected to generators to produce electricity.
- Nuclear power plants work continuously (day and night) and are highly reliable, as they require refuelling only once in 18–24 months.
- India has 21 nuclear reactors and important nuclear power stations at Tarapur, Kudankulam, Kalpakkam, Rawatbhata, Kakrapar and Narora.
- Nuclear energy produces huge amounts of electricity with low greenhouse gas emissions, reducing dependence on fossil fuels like coal and petroleum.
Key Points: Non-Conventional Sources > Biogas Energy
- Biogas is produced by anaerobic decomposition of animal and plant waste (like cattle dung) in the absence of oxygen, mainly producing methane.
- A biogas plant has an underground digester tank where dung-water mixture ferments and releases gas, which is used for cooking, lighting and pumping water.
- The leftover slurry is rich in nutrients and is used as organic manure, improving soil fertility and reducing the need for chemical fertilizers.
- Biogas is a clean, cheap and renewable source of energy, widely used in rural areas through Gobar Gas Plants.
- Compressed Biogas (CBG) is purified biogas with high methane content and is used as an eco-friendly fuel, reducing dependence on fossil fuels and natural gas imports.
Key Points: Major Producers of Minerals and Energy Resources in India
- Iron ore is mainly produced in Jharkhand, Chhattisgarh, Karnataka and Odisha, while coal is largely found in Jharkhand, Chhattisgarh, Odisha, West Bengal and Madhya Pradesh.
- Manganese is a major mineral of Karnataka, Maharashtra, Madhya Pradesh and Odisha, whereas copper is mainly found in Rajasthan, Jharkhand and Madhya Pradesh.
- Mineral oil is produced chiefly in Assam, Gujarat and offshore Maharashtra (Mumbai High); Digboi in Assam is the oldest oilfield in India.
- Mathura Refinery is the largest public sector oil refinery, while Jamnagar Refinery (Gujarat) is the largest private sector refinery in the world.
- Renewable energy leaders include solar energy (Rajasthan, Gujarat, Karnataka), wind energy (Tamil Nadu, Gujarat, Maharashtra), nuclear energy (Tamil Nadu, Karnataka) and biogas (Maharashtra, Karnataka, Uttar Pradesh).
Concepts [15]
- Sources of Energy
- Conventional Sources of Energy > Coal
- Conventional Sources of Energy > Petroleum or Mineral Oil
- Oil Refineries in India
- Conventional Sources of Energy > Natural Gas
- Conventional Sources of Energy > Hydel Power
- Bhakra Nangal Dam
- Hirakud Project
- Non-Conventional Sources > Solar Energy
- Non-Conventional Sources > Wind Energy
- Non-Conventional Sources > Tidal Energy
- Non-Conventional Sources > Geothermal Energy
- Non-Conventional Sources > Nuclear Energy
- Non-Conventional Sources > Biogas Energy
- Major Producers of Minerals and Energy Resources in India
