Energy and Power Resources
Introduction
ENERGY is ESSENTIAL for EVERYTHING — lighting homes, running factories, powering transport, and operating computers. As the world's POPULATION grows and economies DEVELOP, the DEMAND for energy INCREASES. This chapter explores DIFFERENT sources of energy and their ADVANTAGES and DISADVANTAGES.
1. Classification of Energy Sources
| Classification | Definition | Examples |
|---|---|---|
| CONVENTIONAL | TRADITIONAL sources used for many years | Coal, petroleum, natural gas, firewood |
| NON-CONVENTIONAL | NEWER, ALTERNATIVE sources | Solar, wind, nuclear, tidal, geothermal, biogas |
| RENEWABLE | Can be REPLENISHED naturally (never run out) | Solar, wind, hydel, tidal |
| NON-RENEWABLE | LIMITED in quantity — will RUN OUT one day | Coal, petroleum, natural gas |
2. Conventional Sources of Energy
A. Coal
Formation: Formed from PLANTS that were BURIED and COMPRESSED over MILLIONS of years. It is a FOSSIL FUEL.
Types of Coal:
| Type | Carbon Content | Uses |
|---|---|---|
| PEAT | 50–60% | Low-grade; used for domestic fuel |
| LIGNITE | 60–70% | Brown coal; used in thermal power plants |
| BITUMINOUS | 70–90% | Most COMMON; used in industries, railways |
| ANTHRACITE | 90+% | BEST quality; hard, burns cleanly |
Major Coal Fields in India: Jharia, Raniganj, Bokaro (Jharkhand); Korba (Chhattisgarh); Talcher (Odisha); Singrauli (MP/UP)
Disadvantages: Causes AIR POLLUTION; releases CO2; MINING is dangerous
B. Petroleum (Crude Oil)
Formation: Formed from MARINE ORGANISMS buried under SEDIMENTS over millions of years.
Products from Petroleum (Refined through DISTILLATION):
- PETROL (gasoline) — for cars
- DIESEL — for trucks, buses, generators
- KEROSENE — for cooking, heating
- LPG — for cooking
- NAPHTHA — for petrochemicals
- FURNACE OIL — for industries
- BITUMEN — for roads
Major Oil Fields in India: Mumbai High (Arabian Sea — OFFSHORE); Digboi, Assam (ONSHORE — oldest in India); Ankleshwar, Gujarat; Krishna-Godavari basin
Disadvantages: Causes POLLUTION (oil spills, emissions); NON-RENEWABLE; geopolitically SENSITIVE
C. Natural Gas
Formation: Found ALONGSIDE petroleum deposits.
Properties: CLEANER-burning than coal or oil; used for POWER generation, heating, transport (CNG), and as RAW MATERIAL for fertilisers.
Major Fields in India: Mumbai High, Krishna-Godavari basin, Assam, Gujarat
Advantages: Burns CLEANER (less CO2); EFFICIENT; can be TRANSPORTED through pipelines
D. Thermal Power
How it Works: Coal, oil, or natural gas is BURNT to heat water → STEAM → turns TURBINE → generates ELECTRICITY.
Thermal Power Plants in India: Most CITIES have thermal plants near COAL MINES or PORTS.
E. Hydel (Hydroelectric) Power
How it Works: Flowing WATER turns turbines → generates ELECTRICITY. Uses DAMS to store water.
Major Hydel Projects in India:
| Project | State | River |
|---|---|---|
| Bhakra Nangal | Punjab/Himachal | Sutlej |
| Damodar Valley | West Bengal/Jharkhand | Damodar |
| Hirakud | Odisha | Mahanadi |
| Nagarjuna Sagar | Andhra Pradesh | Krishna |
| Tehri | Uttarakhand | Bhagirathi |
Advantages: RENEWABLE; no pollution; CHEAP to operate; provides IRRIGATION too
Disadvantages: EXPENSIVE to build; DISPLACES people; affects ecosystems
3. Non-Conventional Sources of Energy
A. Solar Energy
How it Works: SUNLIGHT is converted into electricity using PHOTOVOLTAIC (PV) CELLS (solar panels).
Uses: Lighting, heating water, POWERING devices, LARGE solar farms
Advantages: RENEWABLE; ABUNDANT (especially in India); CLEAN; LOW maintenance
Disadvantages: INTERMITTENT (no sun at night); HIGH initial cost; needs LARGE areas
India's Solar Potential: India receives 300+ SUNNY days per year. The THAR DESERT has HUGE potential. The JAWAHARLAL NEHRU NATIONAL SOLAR MISSION (2010) aims to make India a LEADER in solar energy.
B. Wind Energy
How it Works: WIND turns the BLADES of wind turbines → generates electricity.
Wind Farms: GROUPS of wind turbines in WINDY locations.
Major Wind Farms in India:
| Location | State |
|---|---|
| Muppandal | Tamil Nadu |
| Jogimatti | Karnataka |
| Jamnagar | Gujarat |
| Satara | Maharashtra |
Advantages: RENEWABLE; CLEAN; GOOD for RURAL areas
Disadvantages: INTERMITTENT (wind doesn't always blow); NOISY; can HARM birds; needs WINDY locations
C. Nuclear Energy
How it Works: URANIUM atoms are SPLIT (nuclear fission) → releases HUGE heat → heats water → STEAM → turbines → electricity.
Nuclear Power Plants in India:
| Plant | State |
|---|---|
| Tarapur | Maharashtra |
| Kalpakkam | Tamil Nadu |
| Narora | Uttar Pradesh |
| Kakrapara | Gujarat |
| Rawatbhata | Rajasthan |
| Kudankulam | Tamil Nadu |
Advantages: HIGHLY EFFICIENT; no air pollution; SMALL amount of fuel → LARGE energy
Disadvantages: RADIOACTIVE WASTE is dangerous; RISK of ACCIDENTS (Chernobyl, Fukushima); HIGH cost; NON-RENEWABLE (uranium is limited)
D. Tidal and Wave Energy
How it Works: The RISE and FALL of ocean TIDES turns turbines → electricity.
Advantages: RENEWABLE; PREDICTABLE (tides are regular)
Disadvantages: EXPENSIVE; limited to COASTAL areas; may affect marine ecosystems
India's Potential: Gulf of Khambhat, Gulf of Kutch, Sunderbans
E. Biogas
How it Works: ANIMAL DUNG and organic waste DECOMPOSE in an airtight tank → produces METHANE gas → used for COOKING and LIGHTING.
Advantages: RENEWABLE; uses WASTE; produces MANURE as by-product; CHEAP; REDUCES deforestation
Disadvantages: SMALL-SCALE production; not suitable for HIGH energy needs
4. Energy Conservation
Why Conserve?
- FOSSIL FUELS are LIMITED and NON-RENEWABLE
- Energy production causes POLLUTION
- SAVING energy SAVES money
- INDIA imports MUCH of its oil — conservation REDUCES dependence
How to Conserve Energy
| Method | Example |
|---|---|
| Use EFFICIENT appliances | LED bulbs, 5-star rated ACs |
| Switch OFF unused devices | Lights, fans, electronics |
| Use PUBLIC transport | Less fuel per person |
| INSULATE buildings | Less heating/cooling needed |
| RENEWABLE energy | Install solar panels at home |
| Carpooling | Share vehicles |
ICSE Exam Focus
2-mark questions
- What is the DIFFERENCE between renewable and non-renewable energy?
- Name TWO conventional sources of energy.
- What is BIOGAS? How is it produced?
4-mark questions
- Explain the ADVANTAGES and DISADVANTAGES of SOLAR energy.
- Compare THERMAL power and HYDROELECTRIC power.
- Why is NUCLEAR energy considered both GOOD and DANGEROUS?
6-mark (essay) questions
- Discuss the CONVENTIONAL and NON-CONVENTIONAL sources of energy with examples.
- Why is ENERGY CONSERVATION important? Describe ways to conserve energy.
Self-Test
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What is the DIFFERENCE between CONVENTIONAL and NON-CONVENTIONAL energy sources? Answer: Conventional sources have been used for a LONG TIME (coal, petroleum, natural gas, hydel). Non-conventional sources are NEWER alternatives (solar, wind, nuclear, tidal, biogas). Most conventional sources are NON-RENEWABLE.
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How is COAL formed? Name the four types in order of quality. Answer: Coal formed from PLANTS buried and compressed over millions of years. Types from LOWEST to HIGHEST quality: PEAT → LIGNITE → BITUMINOUS → ANTHRACITE.
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What are the ADVANTAGES of HYDROELECTRIC power? Answer: It is RENEWABLE, produces NO pollution, has LOW operating costs, and can provide irrigation and flood control through DAMS.
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Why is SOLAR energy IMPORTANT for India? Answer: India receives ABUNDANT sunlight (300+ sunny days/year). Solar energy can provide CLEAN power to remote villages, REDUCE dependence on fossil fuels, and help India meet its CLIMATE goals.
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What are the DISADVANTAGES of NUCLEAR energy? Answer: PRODUCTION of radioactive waste (dangerous for thousands of years), RISK of accidents (Chernobyl, Fukushima), HIGH construction costs, and URANIUM is non-renewable.
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List FOUR ways to CONSERVE energy in daily life. Answer: (1) Switch off LIGHTS and FANS when not in use; (2) Use LED BULBS; (3) Use PUBLIC TRANSPORT instead of private cars; (4) Install SOLAR PANELS for water heating.
