Context & Key Question
- Backdrop: Global climate targets and energy independence goals are driving a massive push for renewable energy.
- Core Issue: Are silicon photovoltaics (Si-PV) still the best option, or should we invest in next-gen solar technologies with higher efficiency and lower environmental impact?
Relevance : GS 3(Environment and Ecology)
Silicon Photovoltaics (Si-PV): Overview
- Invented: 1954, Bell Labs (USA).
- Efficiency:
- Lab efficiency: 18–21%.
- Real-world (in-field) efficiency: 15–18%.
- Global Production:
- 80% of supply from China.
- India: Domestic capacity at ~6 GW, expected to rise.
Efficiency vs. Land Constraints
- Efficiency matters: Doubling efficiency → halves land requirement.
- Land crunch:
- Rapid urbanization.
- Environmental concerns limiting greenfield solar expansion.
- Implication: Silicon PV’s lower efficiency makes it less viable in space-constrained or high-demand areas.
Alternative Photovoltaic Technologies
- Gallium Arsenide (GaAs) Thin-Film: Up to 47% efficiency.
- Commercial-readiness: Many next-gen PVs are lab-tested, demonstration-ready, and awaiting commercial deployment.
Energy & Climate Dynamics
- Renewable Energy Installed (India): 4.45 TWh (by end-2024).
- Atmospheric CO₂: Increased from 350 ppm (1990) to ~425 ppm (2025).
- Implication: Renewable expansion isn’t keeping pace with energy demand.
Green Hydrogen: Promise vs. Reality
- Production method: Electrolysis using renewable power.
- Challenges:
- Electrolysis is energy-intensive.
- Storage & transport of hydrogen is difficult (leaky, low-density).
- Energy cascade losses: From Si-PV → electrolysis → storage → reconversion = compounding inefficiencies.
Proposed Alternatives
- Molecular Carriers: Convert H₂ to green ammonia (NH₃) or green methanol (CH₃OH) for transport.
- But reverse conversion still demands high energy.
- Artificial Photosynthesis (APS):
- Directly produce fuels from H₂O, CO₂/N₂, and sunlight.
- Still in lab-stage, but promising for future.
- CO₂ Recycling: Turn CO₂ into useful fuels = climate mitigation + energy solution.
Europe’s Lead: RFNBO
- Renewable Fuels of Non-Biological Origin (RFNBO):
- Fuels made using renewables but not from biomass.
- Includes green hydrogen, methanol, ammonia from sunlight and air.
- Policy push: India urged to follow suit to reduce 85% energy import dependence.
India’s Strategic Needs
- Current import dependence: 85% of energy (oil, coal, gas).
- Geopolitical vulnerability: Global conflicts + price shocks.
- Recommendation: Ramp up R&D spending, foster public-private innovation.
Conclusion & Takeaways
- Green hydrogen & Si-PV are helpful but not enough.
- Efficiency and energy economics need urgent innovation.
- India must diversify energy strategies to:
- Improve energy density.
- Optimize land use.
- Enable cleaner, scalable fuels.
- Proactive R&D investment today is more cost-effective than reactive damage control tomorrow.
