BharatNotes Note: This chapter was removed from the NCERT curriculum in the 2022 rationalization. Retained here as energy forms, conversion, and power are fundamental to understanding renewable energy, energy efficiency, hydropower, and India's energy sector — GS3 topics.
Energy is the currency of the physical world — and of UPSC GS3. Every question on hydropower, nuclear energy, energy efficiency, electric vehicles, or India's power sector is grounded in the concepts of this chapter. Understanding the forms of energy and their conversion chains allows UPSC aspirants to analyse any energy technology critically — from Tehri Dam to India's nuclear power plants to LED energy efficiency programmes.
PART 1 — Quick Reference Tables
Forms of Energy and UPSC Relevance
| Form of Energy | Definition / Examples | UPSC Relevance |
|---|---|---|
| Kinetic Energy (KE) | Energy of motion; KE = ½mv² | Wind turbines (wind KE → electrical); tidal current generators; bullet/missile |
| Gravitational Potential Energy (GPE) | Energy due to height; GPE = mgh | Hydroelectric dams (water at height → KE → electricity); pumped storage |
| Chemical Energy | Stored in chemical bonds; food, fuel, batteries | Thermal power plants; EVs (battery); cooking gas; biofuels; food nutrition |
| Nuclear Energy | Stored in atomic nuclei; E = mc² | Nuclear power plants (fission); nuclear weapons; nuclear triad |
| Thermal (Heat) Energy | Kinetic energy of molecules | Geothermal energy; waste heat recovery; efficiency losses |
| Electrical Energy | Flow of charges; most versatile form | All grid electricity; transmission losses; smart meters |
| Electromagnetic (Radiant) | Light, radio waves, X-rays | Solar PV (photons → electrical); solar thermal; satellite communication |
India's Hydropower — Key Projects
| Project | State | Capacity | Notes |
|---|---|---|---|
| Tehri Dam (Stage 1) | Uttarakhand | 1,000 MW | India's tallest dam (260.5 m); on Bhagirathi River; R&R controversy |
| Sardar Sarovar Dam | Gujarat | 1,450 MW | On Narmada; Narmada Bachao Andolan; Supreme Court litigation |
| Bhakra Nangal | Punjab/Himachal Pradesh | 1,325 MW | India's first large multipurpose dam; Sutlej River |
| Dibang Multipurpose Project | Arunachal Pradesh | 2,880 MW (proposed) | India's largest proposed dam; environmental clearance pending |
| Parbati Hydroelectric Project | Himachal Pradesh | 800 MW | High-altitude project; challenging terrain |
Energy Units — Quick Reference
| Unit | Equivalent | Context |
|---|---|---|
| 1 Joule (J) | Base SI unit of energy | Scientific calculations |
| 1 Kilowatt-hour (kWh) | 3.6 × 10⁶ J = 3.6 MJ | Electricity billing ("1 unit") |
| 1 Calorie (food) | 4.184 J | Food energy (note: 1 food Calorie = 1 kcal = 1,000 calories) |
| 1 Watt (W) | 1 J/s | Power unit |
| 1 Horsepower (hp) | 746 W | Engine power ratings |
PART 2 — Detailed Notes
1. Work — Scientific Definition
In science, work is done on an object only when:
- A force is applied on the object
- The object moves in the direction of (or with a component in the direction of) the force
W = F × d × cos θ
where θ is the angle between the force direction and the direction of displacement.
- θ = 0° (force and motion in same direction): W = Fd (maximum positive work)
- θ = 90° (force perpendicular to motion): W = 0 (no work done — e.g., a porter walking on a flat road while carrying a load on their head; gravity acts downward, motion is horizontal → gravity does NO work)
- θ = 180° (force opposes motion): W = −Fd (negative work done — e.g., friction does negative work on a sliding object)
Work is a scalar quantity measured in Joules (J). 1 Joule = 1 Newton × 1 metre. The popular usage ("a person works hard") is NOT the scientific definition — if a person pushes a wall that doesn't move, the wall does NO work in the scientific sense.
2. Kinetic Energy
Kinetic energy (KE) is the energy possessed by an object due to its motion.
KE = ½mv²
The dependence on v² is crucial: doubling speed quadruples kinetic energy. This has enormous real-world consequences:
- A car at 80 km/h has 4 times the kinetic energy of a car at 40 km/h — and requires 4 times the braking distance
- Why speeding kills: In a crash, all KE must be dissipated. At 4× KE, the forces and deformations on occupants are 4 times greater.
- Wind energy: KE of wind = ½ × (mass of air) × v². Wind at 10 m/s has 8 times more energy than wind at 5 m/s (because 10³/5³ = 8) — this is the Betz limit and why wind turbine siting (high wind speed locations) is critical.
3. Potential Energy
Potential energy is stored energy — the capacity to do work based on position, configuration, or state.
Gravitational PE = mgh (mass × g × height)
Other forms of potential energy:
- Elastic PE: Compressed spring, stretched bowstring, car suspension
- Chemical PE: Stored in bonds — coal, natural gas, food, batteries, explosives
- Nuclear PE: Binding energy in atomic nuclei — released in fission (nuclear power plants, atomic bombs) or fusion (hydrogen bombs, the Sun)
UPSC GS3 — Hydroelectric Power and India:
Hydroelectricity converts gravitational potential energy of water stored at height into electrical energy through this energy conversion chain:
Gravitational PE (water at reservoir height) → Kinetic energy (falling water) → Rotational KE (turbine rotation) → Electrical energy (generator)
India's hydropower capacity: Approximately 47 GW installed large hydropower + ~5 GW small hydro (<25 MW). Total hydropower potential ~150 GW (exploited less than 35% so far). Target: 60 GW by 2030 (National Electricity Plan).
Pumped Storage Hydropower (PSH): A form of large-scale energy storage — excess grid electricity (from solar/wind) is used to pump water to an upper reservoir; during peak demand, water released through turbines generates power. India has 7,175.6 MW (7.18 GW) operational pumped storage capacity across 10 projects (CEA, December 31, 2025) -- up from the earlier ~4.7 GW. PSH is the largest form of grid-scale energy storage globally. Critical for integrating intermittent renewables (solar/wind) into the grid. CEA's Roadmap to 100 GW PSH by FY2035-36 (January 2026): 11,620 MW under construction; 74,940 MW under survey/investigation; Rs 5.8 lakh crore investment roadmap -- India's primary grid-balancing strategy to absorb 500 GW renewable energy by 2030.
Key controversies — hydropower is not without cost:
- Tehri Dam (Uttarakhand): Displaced ~100,000 people; drowned the historic town of Tehri; seismic zone risk (located in earthquake-prone Himalayan region)
- Sardar Sarovar (Narmada): Narmada Bachao Andolan (led by Medha Patkar) — highlighted inadequate resettlement and rehabilitation; landmark SC judgments on height of dam (2000)
- Dibang (Arunachal Pradesh): Concerns from environmentalists about impact on biodiversity hotspot; Eastern Himalayan ecology; tribal displacement
4. Law of Conservation of Energy
Energy cannot be created or destroyed — it can only be converted from one form to another. The total energy of a closed system remains constant.
Pendulum example: At the highest point → all PE, zero KE; at lowest point → all KE, zero PE; at any intermediate point → PE + KE = constant (= total mechanical energy, if no friction).
Falling stone example: PE (at height) → KE (during fall) → Sound + Heat (on impact with ground). At every instant: total energy = PE + KE = constant (ignoring air resistance).
Energy conversion chain — coal-fired power plant: Chemical PE (coal) → Thermal energy (combustion) → KE of steam → Rotational KE of turbine → Electrical energy (generator) → Light/heat/motion at consumer end.
At each conversion step, some energy is lost as heat (thermal dissipation). This is why no machine or power plant is 100% efficient — the Second Law of Thermodynamics: in any energy conversion, some energy becomes unavailable for doing useful work (entropy increases).
5. Power
Power is the rate of doing work (or rate of energy transfer).
P = W/t = Energy/time
Unit: Watt (W) = 1 Joule per second. Larger units: kilowatt (kW = 1,000 W), megawatt (MW = 10⁶ W), gigawatt (GW = 10⁹ W).
1 horsepower (hp) = 746 W (used in vehicle engine ratings).
Power tells you how fast work is done, not how much total work. A 100 W bulb uses energy at the rate of 100 J per second. Running up stairs in 10 seconds vs 20 seconds — same work is done, but twice the power is used in the faster case.
Electricity billing uses kWh (kilowatt-hours), not Joules: 1 Unit of electricity = 1 kWh = 1,000 W × 3,600 s = 3.6 × 10⁶ J = 3.6 MJ. A 1,000 W (1 kW) appliance running for 1 hour consumes 1 unit. This is what the electricity meter measures. India's average domestic electricity tariff varies by state (Rs 4–10 per unit). High consumption → higher slab → higher tariff (progressive tariff structure to cross-subsidize poor consumers).
6. Energy Efficiency and India
Energy efficiency = (Useful output energy / Total input energy) × 100%
No machine achieves 100% efficiency (friction, heat losses, sound).
Lighting efficiency comparison:
- Incandescent bulb: ~5% efficient (converts 5% of electrical energy to light; 95% wasted as heat)
- CFL (Compact Fluorescent Lamp): ~25% efficient
- LED (Light Emitting Diode): ~40–80% efficient
- LEDs consume up to 75–80% less energy than incandescent bulbs for the same light output
UPSC GS3 — India's Energy Efficiency Initiatives:
Bureau of Energy Efficiency (BEE): Statutory body under Ministry of Power. Implements energy efficiency programmes across sectors.
Star Rating Scheme for Appliances: BEE's voluntary (now mandatory for some) star ratings on ACs, refrigerators, washing machines, TVs. 5-star = most efficient. Saves consumers money; reduces grid load; reduces emissions.
UJALA Scheme (Unnat Jyoti by Affordable LEDs for All): Launched 2015 by Energy Efficiency Services Limited (EESL). Distributed over 360 million LED bulbs at subsidised prices. Estimated annual energy savings: ~47 billion kWh. One of the world's largest LED distribution programmes.
Energy Conservation Act 2001 (amended 2022): The Energy Conservation (Amendment) Act 2022 introduced:
- Carbon Credit Trading Scheme (CCTS): India's domestic carbon market; entities can earn and trade carbon credits for exceeding energy efficiency targets
- Renewable Energy Certificates (RECs) included in BEE's mandate
- Energy Conservation Building Code (ECBC) made mandatory for commercial buildings
- Standards for EVs and EV charging infrastructure
- Designated Consumers (DCs): Large energy consumers (>250 tonnes oil equivalent per year) must comply with energy consumption norms
PACE-D Programme: NITI Aayog / USAID initiative for energy efficiency in industry and buildings.
[Additional] India's total installed power capacity (as of Dec 2025, CEA): ~513.73 GW total; non-fossil fuel sources: 266.79 GW (51.93%) — a historic milestone. India crossed 50% non-fossil capacity in June 2025 — more than 5 years ahead of its NDC (Paris Agreement) target date of 2030. Breakdown: Solar ~150 GW, Large Hydro ~51 GW, Wind ~56 GW, Bio-energy ~12 GW, Small Hydro ~5 GW, Nuclear ~8.88 GW. India ranks 3rd globally in renewable energy installed capacity (after China and USA). Target: 500 GW non-fossil capacity by 2030 (NDC 2.0; COP26 commitment); total capacity projected to double to ~1,121 GW by 2035-36 (CEA 20th Electric Power Survey Midterm Review, April 2026).
7. Nuclear Energy — E = mc²
Einstein's famous equation E = mc² reveals that mass and energy are interchangeable. Even a tiny mass contains a stupendous amount of energy (c = 3 × 10⁸ m/s; c² = 9 × 10¹⁶ m²/s²).
1 kg of matter converted entirely to energy = 9 × 10¹⁶ J ≈ 21 megatons of TNT equivalent.
In practice, nuclear fission (splitting of heavy nuclei like U-235 or Pu-239) converts less than 0.1% of mass to energy — but even this tiny fraction yields millions of times more energy than chemical reactions (burning coal).
India's nuclear power:
- Total installed nuclear capacity: ~8,880 MW (8.88 GW) (as of April 2025, post-RAPP-7 commissioning); 25 reactors at 8 sites (NPCIL/PIB)
- Operates under India's unique three-stage nuclear programme (Homi Bhabha, 1954):
- Stage 1: PHWRs (Pressurised Heavy Water Reactors) using natural uranium (U-238 + U-235)
- Stage 2: FBRs (Fast Breeder Reactors) using Pu-239 (bred from U-238 in Stage 1); India's first commercial FBR (PFBR) at Kalpakkam, Tamil Nadu (under commissioning)
- Stage 3: Thorium-based reactors — India has the world's largest thorium reserves (~25% of global reserves, ~846,000 tonnes; AMD/DAE data; PIB 2025-26 confirmed #1 ranking), mainly in Kerala monazite sands; goal is energy security for centuries
[Additional] 11a. Green Hydrogen — Electricity as Chemical Energy Storage
The chapter covers energy conversion (electrical → chemical → kinetic, etc.) and mentions green hydrogen in the context of ammonia (Ch03). What is missing is the conceptual explanation of why hydrogen is an energy carrier, not an energy source — a distinction that UPSC examiners test explicitly, and that connects directly to this chapter's energy conversion framework.
Hydrogen as an Energy Carrier: Hydrogen (H₂) does not exist freely in nature in significant quantities. It must be produced using energy — therefore it is an energy carrier (stores and transports energy) rather than an energy source (like sunlight or coal).
The electrolysis-to-hydrogen energy conversion chain: Surplus solar/wind electricity → Electrolysis (electrical energy splits water: 2H₂O → 2H₂ + O₂) → Chemical energy stored in H₂ bonds → H₂ transported/stored → Fuel cell (reverse: H₂ + O₂ → H₂O + electricity) or combustion (H₂ + O₂ → H₂O + heat) → End use
This is an energy storage loop: surplus renewable electricity (unavailable when the Sun is not shining / wind not blowing) is "banked" as hydrogen, then reconverted when needed. It complements pumped storage hydro (PSH) for long-duration storage over days/weeks.
Energy density advantage: Hydrogen: ~120 MJ/kg; petrol: ~44 MJ/kg — hydrogen stores ~3× more energy per kg. This makes it viable for heavy transport (trucks, shipping, aviation) where battery weight is prohibitive.
[Additional] National Green Hydrogen Mission (NGHM) — GS3 (Energy Security / Industry Decarbonisation):
Mission at a glance:
- Launched: January 4, 2023 (Cabinet approval)
- Lead ministry: Ministry of New and Renewable Energy (MNRE)
- Target: 5 million tonnes (MT) green hydrogen production per year by 2030 + 125 GW additional renewable energy capacity (to power electrolysers)
- Electrolyser manufacturing target: 15 GW/year domestic capacity by 2030
Programme status (May 2025, MNRE):
- 15 companies awarded 3,000 MW/year electrolyser manufacturing capacity under SIGHT (Strategic Interventions for Green Hydrogen Transition) incentive scheme
- 19 companies allocated 8.62 lakh tonnes/year green hydrogen production capacity
- Green Hydrogen Certification Scheme of India (GHCI, April 2025): Launched to certify hydrogen as "green" by measuring lifecycle GHG emissions — essential for export markets (EU's RFNBO certification; Japan/South Korea hydrogen import agreements)
Key applications for India:
| Sector | Current fuel | Green H₂ substitution |
|---|---|---|
| Ammonia/fertilisers | Grey ammonia (natural gas) | Green ammonia — eliminates ~5 MT CO₂/year from fertiliser sector |
| Steel | Coking coal (BF-BOF) | H₂-based direct reduced iron (H₂-DRI) — eliminates ~2 kg CO₂/kg steel |
| Heavy transport | Diesel | Hydrogen fuel cell trucks — zero tailpipe emissions |
| Shipping | Bunker fuel | Methanol/ammonia from green H₂ |
India's green hydrogen export ambition: India aims to become one of the lowest-cost green hydrogen producers globally (target <$1/kg by 2030 vs ~$3-5/kg currently), leveraging cheap renewable electricity. Export partnerships with Germany (energy partnership 2023), Japan, and South Korea are under negotiation.
UPSC synthesis: Green hydrogen connects energy physics (electrolysis = electrical energy → chemical energy), climate policy (decarbonisation of hard-to-abate sectors), industrial policy (SIGHT scheme, Make in India electrolysers), and trade (export potential). The "energy carrier vs energy source" distinction is a direct Prelims MCQ target.
[Additional] 11b. Ocean Energy — Tidal, Wave, and OTEC: India's Blue Energy Frontier
The chapter covers work, energy, and power and mentions various energy forms. It does not cover ocean energy — tidal, wave, and Ocean Thermal Energy Conversion (OTEC) — a growing GS3 topic linked to India's Deep Ocean Mission, NIOT's OTEC plant in Lakshadweep, and India's declared target of 30 GW offshore wind + ocean energy by 2030.
Key Terms — Ocean Energy:
| Term | Meaning |
|---|---|
| Tidal energy | Energy from the rise and fall of ocean tides caused by gravitational pull of the Moon (primarily) and Sun; tidal barrages or tidal stream turbines convert tidal kinetic/potential energy to electricity |
| Wave energy | Energy from wind-generated surface waves; waves carry both kinetic energy (wave motion) and potential energy (raised water surface); converted by various wave energy converter (WEC) devices |
| OTEC (Ocean Thermal Energy Conversion) | Exploits the temperature difference between warm surface ocean water (~25–30°C) and cold deep ocean water (~5°C at ~1,000 m depth) to run a thermodynamic cycle; requires a temperature differential of at least 20°C |
| Closed-cycle OTEC | Uses a working fluid (ammonia) that evaporates at warm surface water temperature → drives turbine → condensed by cold deep water → back to start; most common OTEC design |
| Open-cycle OTEC | Uses ocean water itself as the working fluid; flash evaporation of warm surface water → turbine → condensed by cold deep water; also produces fresh water as a by-product |
| NIOT (National Institute of Ocean Technology) | Chennai-based institute under Ministry of Earth Sciences (MoES); operates India's primary OTEC research; developed and deployed OTEC units in Lakshadweep |
[Additional] Ocean Energy — Tidal, Wave, OTEC, India's Potential, and Deep Ocean Mission (GS3 — Energy / Science and Technology):
Ocean energy types — physics and India's potential:
| Type | Energy source | India's estimated potential | Best sites in India |
|---|---|---|---|
| Tidal (range) | Gravitational PE of tidal rise/fall | ~12,455 MW total | Gulf of Khambhat (7,000 MW), Gulf of Kutch (1,200 MW), Sundarbans (~100 MW) |
| Tidal (stream/current) | Kinetic energy of tidal currents | Being assessed | Palk Strait, various coastal channels |
| Wave | Wind-driven surface wave KE+PE | ~40,000 MW (India's west coast) | Karnataka/Kerala/Maharashtra coast |
| OTEC | Ocean thermal gradient (surface vs deep) | ~1,80,000 MW (theoretical maximum) | Lakshadweep Islands + Andaman & Nicobar Islands (tropical waters; year-round warm surface) |
| Salinity gradient | Osmotic pressure between fresh and salt water | Being studied | River deltas |
Tidal energy — key locations:
| Location | Tidal range | Estimated potential |
|---|---|---|
| Gulf of Khambhat (Gujarat) | ~11–12 m | ~7,000 MW — India's highest |
| Gulf of Kutch (Gujarat) | ~5–7 m | ~1,200 MW |
| Sundarbans (West Bengal) | ~3–5 m | ~100 MW |
Why no commercial tidal plant in India yet:
- Cost is 3–5 times higher than onshore wind/solar
- Civil engineering for barrages is complex and environmentally disruptive (affects fisheries, navigation, ecology)
- India has prioritised cheaper solar and wind; tidal remains in pilot/study phase
OTEC — the physics:
| Parameter | Detail |
|---|---|
| Principle | Carnot-like thermodynamic cycle exploiting temperature differential between warm surface water and cold deep water |
| Minimum required ΔT | ~20°C temperature difference (between surface and deep water at ~1,000 m) |
| India's tropical advantage | Lakshadweep + A&N Islands have surface temp ~28–30°C year-round; deep water (~1,000 m) at ~5–7°C; ΔT ≈ 22–25°C — suitable for OTEC |
| By-product | Cold, nutrient-rich deep water brought up can be used for: (1) desalination (cold pipe chilling → condensation of fresh water); (2) air conditioning (chilled water cooling systems); (3) mariculture (nutrient-rich deep water supports aquaculture) |
NIOT's OTEC work at Lakshadweep:
| Project | Detail |
|---|---|
| 1 MW OTEC floating platform | India's first offshore OTEC demo; deployed by NIOT; technical challenges in long-duration operation |
| 100 kW gross OTEC (Deep Ocean Mission component) | NIOT Chennai working on 100 kW closed-cycle OTEC demonstration; operational targets 2024-26 |
| 100 m³/day OTEC desalination | NIOT's project at Kavaratti Island, Lakshadweep — produces 100 cubic metres of fresh water per day using OTEC cold water pipe for condensation; addresses Lakshadweep's severe freshwater scarcity |
Deep Ocean Mission (DOM) — ocean energy components:
| Parameter | Detail |
|---|---|
| Cabinet approval | June 16, 2021 |
| Ministry | Ministry of Earth Sciences (MoES) |
| Total budget | ₹4,077 crore over 5 years |
| Ocean energy component | Includes DPR for 10 MW OTEC pilot plant + DPR for 5 MLD OTEC-based desalination plant |
| Deep sea mining | Polymetallic nodules in Central Indian Ocean Basin (CIOB) |
| Matsya 6000 | Manned submersible; 6,000 m rated depth; NIOT-developed |
MNRE's renewable energy classification:
| Decision | Detail |
|---|---|
| MNRE declared ocean energy = renewable energy | PIB, January 2020 |
| Eligible for | Non-solar Renewable Purchase Obligation (RPO) — distribution companies can meet RPO targets by buying ocean energy |
| Implication | Ocean energy projects now attract renewable energy tax incentives, banking benefits, and ISTS (Inter-State Transmission System) waiver |
Global OTEC status — comparison:
| Country | OTEC status |
|---|---|
| USA (Hawaii) | 105 kW OTEC plant operational (NELHA facility, Hawaii) |
| Japan | OTEC demo plants in Okinawa; commercial scale being studied |
| India | NIOT demos in Lakshadweep; 100 kW demonstration under Deep Ocean Mission |
| China | 100 kW OTEC pilot in South China Sea |
UPSC synthesis: Key exam facts: India's tidal potential = ~12,455 MW total = Gulf of Khambhat ~7,000 MW (tidal range 11-12m) + Gulf of Kutch ~1,200 MW; wave potential = ~40,000 MW; OTEC potential = ~1,80,000 MW (theoretical); NO commercial tidal plant in India yet; OTEC uses temperature difference between warm surface (~25-30°C) and cold deep water (~5°C at 1,000m) = needs ≥20°C ΔT; best OTEC sites = Lakshadweep + A&N Islands; NIOT (MoES, Chennai) = leads OTEC research; Deep Ocean Mission = Cabinet June 2021 = MoES = ₹4,077 crore = includes 10 MW OTEC DPR; MNRE = ocean energy = renewable = January 2020. Prelims trap: India has NO commercial-scale tidal power plant (unlike UK/France/South Korea); OTEC is most promising for India NOT in Gujarat/Rajasthan (where tidal is strong) but in Lakshadweep and A&N Islands (tropical, high ΔT); OTEC by-product = fresh water (desalination) + cold water for air conditioning + nutrients for mariculture; NIOT is under Ministry of Earth Sciences (MoES) — NOT MNRE; INCOIS (Indian National Centre for Ocean Information Services, Hyderabad) provides ocean data and warnings — different from NIOT which does engineering/technology.
Exam Strategy
Prelims traps:
- Work is a scalar quantity, not a vector — direction of force matters only for calculating its magnitude
- A person holding a heavy box stationary — no work is done (no displacement); muscles tire due to isometric contraction, not work in physics sense
- KE depends on v² — doubling speed → 4× KE (not 2×); tripling speed → 9× KE — important for road safety questions
- 1 kWh = 3.6 × 10⁶ J (not 3.6 × 10³) — often tested in numerical form
- 1 horsepower = 746 W (not 700 W or 1000 W)
- LED bulbs are far more efficient than incandescent — UJALA scheme distributed LEDs (not CFLs)
- India's three-stage nuclear programme target is thorium utilization in Stage 3 — India's strategic resource
Mains linkages:
- Energy conversion chain → efficiency losses → need for energy conservation → BEE star ratings → carbon credits (ECAmendment 2022)
- Hydropower → energy security vs ecological concerns → free flow rivers → Western Ghats Ecology Expert Panel → Gadgil Report vs Kasturirangan Report
- Nuclear three-stage programme → thorium → energy independence → non-proliferation regime (India outside NPT) → India-US civil nuclear deal (2008)
Practice Questions
Prelims:
Consider the following statements about India's nuclear power programme: 1. India follows a three-stage nuclear power programme. 2. The Fast Breeder Reactor at Kalpakkam uses thorium as primary fuel. 3. India has the world's largest thorium reserves. Which of the above is/are correct?
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3
(Stage 2 FBR uses Pu-239 as fuel, not thorium — statement 2 is wrong; India IS the world's largest holder of thorium reserves per AMD/DAE/PIB 2025-26 — statement 3 is correct)UJALA scheme, sometimes seen in news, is related to:
(a) Solar energy promotion in rural areas
(b) Energy subsidy for BPL households
(c) Distribution of LED bulbs for energy efficiency
(d) Promoting biogas plants under MNRE
Mains:
- Explain the three-stage nuclear power programme of India. In this context, discuss how India's thorium reserves can contribute to long-term energy security. (CSE Mains 2020, GS Paper 3, 15 marks)
