Renewable Energy and Sustainability
Overview
Renewable energy has emerged as a critical topic in UPSC Prelims, appearing consistently across environment, economy, and current affairs sections. India's ambitious target of 500 GW non-fossil fuel capacity by 2030 and its commitments under the Paris Agreement make this topic strategically important. Questions typically test understanding of energy sources, government schemes, international initiatives, and India's energy transition roadmap.
This topic bridges multiple syllabus areas—environmental sustainability, economic development, and international relations. Students must grasp the technical basics of each energy source, India's installed capacities, flagship programmes like the International Solar Alliance, and energy efficiency measures. The examiner often frames questions around comparing energy sources, identifying correct statements about schemes, or matching organisations with their functions.
Key Concepts
- Renewable vs Non-renewable distinction: Renewable sources replenish naturally within human timescales (solar, wind, hydro, biomass, geothermal); non-renewable sources (coal, petroleum, natural gas, nuclear) have finite stocks and take millions of years to form.
- Grid parity: The point where renewable energy costs equal or fall below conventional grid electricity costs. Solar has achieved grid parity in most Indian states, making it commercially viable without subsidies.
- Capacity factor: Ratio of actual energy output to maximum possible output over a period. Solar averages 15-20%, wind 25-35%, while thermal plants achieve 60-80%. This explains why installed capacity differs from actual generation.
- Intermittency challenge: Solar and wind are variable sources dependent on weather and time. This necessitates energy storage solutions (batteries, pumped hydro) or grid balancing with baseload power.
- Energy mix approach: India pursues diversified energy sources rather than dependence on single source—ensures energy security and balances intermittency of renewables.
- Decentralised energy: Rooftop solar and micro-grids enable power generation at consumption point, reducing transmission losses (which average 15-20% in India) and empowering rural areas.
- Green hydrogen: Hydrogen produced using renewable electricity through electrolysis. India's National Green Hydrogen Mission targets 5 MMT annual production by 2030.
Key Facts
| Energy Source | Key Characteristics | India's Status (2024) |
|---|---|---|
| Solar | Photovoltaic cells convert sunlight directly to electricity; concentrated solar uses mirrors/lenses for thermal generation | ~75 GW installed; Rajasthan, Gujarat lead; target 280 GW by 2030 |
| Wind | Kinetic energy of air converted via turbines; requires minimum 5 m/s wind speed | ~45 GW installed; Tamil Nadu, Gujarat, Karnataka lead; offshore wind potential of 70 GW |
| Hydro | Potential energy of water at height; large hydro (>25 MW) often excluded from renewable category | ~47 GW large hydro; ~5 GW small hydro; Uttarakhand, Himachal major states |
| Biomass | Organic matter (crop residue, animal waste, wood) burned or converted to biogas/biofuel | ~10 GW installed; addresses stubble burning; GOBAR-DHAN scheme promotes |
| Geothermal | Heat from Earth's interior; limited potential in India | Negligible capacity; Puga Valley (Ladakh), Tattapani (Chhattisgarh) have potential |
International Solar Alliance (ISA):
- Launched 2015 at COP21, Paris; HQ in Gurugram
- Joint initiative of India and France
- Originally limited to countries between Tropics of Cancer and Capricorn; now open to all UN members
- 120+ member countries; focuses on solar deployment in developing nations
- Key programmes: One Sun One World One Grid (OSOWOG), Solar Risk Mitigation Initiative
Key Energy Efficiency Programmes:
- PAT (Perform, Achieve, Trade): Mandates energy efficiency targets for designated consumers; tradeable energy saving certificates
- UJALA: LED bulb distribution programme; distributed 370+ crore LEDs
- Standards & Labelling: BEE star ratings for appliances (1-5 stars)
- Energy Conservation Building Code (ECBC): Mandatory for commercial buildings above threshold
- National Mission for Enhanced Energy Efficiency: One of eight missions under NAPCC
Worked Examples
Example 1: Which of the following statements about International Solar Alliance is/are correct?
- It was launched at the United Nations Climate Change Conference in Paris
- Only countries located between Tropic of Cancer and Capricorn can become members
- Its headquarters is located in New York
Solution: Statement 1 is correct—ISA was launched at COP21 in Paris (November 2015). Statement 2 is incorrect—membership was originally limited to tropical countries but was amended in 2020 to include all UN member states. Statement 3 is incorrect—HQ is in Gurugram, India, not New York. Answer: 1 only
Example 2: Consider the following renewable energy sources:
- Solar thermal
- Tidal energy
- Geothermal energy
Which of the above can provide baseload power?
Solution: Baseload power requires consistent, reliable generation. Solar thermal with molten salt storage can provide power for several hours after sunset but remains somewhat variable. Tidal energy is predictable (based on lunar cycles) but still intermittent. Geothermal energy provides consistent heat from Earth's interior, available 24/7, making it ideal for baseload. Answer: Geothermal energy (3 only) is the most reliable baseload source among these options.
Common Mistakes
- Confusing installed capacity with actual generation → Installed capacity (MW) indicates maximum possible output; actual generation depends on capacity factor. India may have more solar capacity than a neighbouring country but generate less if capacity factors differ.
- Assuming all hydro counts as renewable → Large hydro projects (>25 MW) are often classified separately due to environmental concerns (submergence, displacement). Ministry of Power considers large hydro as renewable, but international standards and some government schemes treat it differently.
- Believing nuclear energy is renewable → Nuclear is non-renewable (uranium is finite) but is a clean/low-carbon source. Examiner may test this distinction.
- Thinking ISA membership is still limited to tropical countries → The 2020 amendment opened membership to all UN members. This is a frequently tested updated fact.
- Confusing solar PV and solar thermal → PV directly converts light to electricity using semiconductors. Solar thermal uses mirrors/lenses to concentrate heat for steam-based generation or heating applications.
Quick Reference
- India's RE target: 500 GW non-fossil capacity by 2030 (Panchamrit commitment)
- Current RE installed capacity: ~180 GW (including large hydro)
- ISA: India-France initiative, HQ Gurugram, 120+ members, all UN states eligible
- OSOWOG: One Sun One World One Grid—transnational solar grid concept
- BEE: Bureau of Energy Efficiency—nodal agency for energy efficiency
- RPO: Renewable Purchase Obligation—mandates minimum RE purchase by discoms
- Green hydrogen: Produced via electrolysis using renewable power; target 5 MMT by 2030