Coal and India’s Energy Transition

Current Role of Coal in India

Dominant Energy Source: ~73% of India’s electricity is generated from coal.
Young Coal Fleet: Most coal-based power plants are under 15 years old, raising concerns about stranded assets if phased out prematurely.
Employment Impact: Coal mining, transport, and thermal power provide livelihoods to ~4 million (40 lakh) people.
Grid Stability: Coal ensures baseload power; without affordable storage, large-scale renewable substitution could destabilize supply.

Biochar and Biocoal – Sustainable Alternatives

Biochar:
- Produced by low-temperature pyrolysis (~500°C) of biomass.
- Acts as a carbon sink, sequestering carbon in soils.
- Enhances soil fertility and water retention.
- Retains tar content.
Biocoal:
- Produced by high-temperature pyrolysis (~900°C) of biomass.
- Carbon-neutral and usable as a direct substitute for coal in power and industry.
- Loses tar during formation, burns cleaner than biochar or coal.

Comparison: Coal vs Charcoal vs Biochar vs Biocoal

Parameter	Coal	Charcoal	Biochar	Biocoal
Origin	Fossil fuel (millions of years)	Partial combustion of wood (~400°C)	Low-temp pyrolysis (~500°C)	High-temp pyrolysis (~900°C)
Carbon Neutrality	❌ Not carbon-neutral	❌ Not carbon-neutral	✅ Carbon sink (soil application)	✅ Carbon-neutral fuel
Emissions	High CO₂, SO₂, NOx, particulates, heavy metals	Emits CO₂, particulates, retains tar	Minimal (soil use, not burnt)	Much cleaner, low SO₂/NOx, no tar
Applications	Power plants, steel, cement	Cooking, heating, small metallurgy	Soil fertility, carbon sequestration	Direct substitute for coal in power & industry
Energy Density	Very high (24–35 MJ/kg)	Moderate (~28 MJ/kg)	Low (not for fuel)	Comparable to coal (~20–25 MJ/kg)
Environmental Impact	Severe GHG emissions, pollution	Unsustainable wood use	Improves soil health & climate	Cleaner than coal, scalable
Residue/By-products	Fly ash, toxic metals	Ash, retains tar	Nutrient-rich soil amendment	Cleaner ash, minimal tar
Economic Aspects	Cheap but high hidden costs	Traditional, inefficient at scale	Valuable in carbon credit markets	Scalable, usable in co-firing
Challenges	Pollution, stranded assets, livelihoods	Inefficient, deforestation risk	Limited awareness, scaling issues	Needs biomass supply & infrastructure

Challenges in Phasing Out Coal

Energy Security & Grid Stability – Coal is crucial for round-the-clock power.
Stranded Asset Risk – Premature plant closures could trigger financial instability.
Employment Concerns – Transition affects millions of coal-dependent livelihoods.
Storage Limitations – Affordable large-scale storage for renewables is not yet available.
Climate Finance Gap – International funding is insufficient for a fair transition.

Environmental Concerns from Coal

Major source of GHG emissions (CO₂, CH₄, N₂O).
Pollutants: SO₂, NOx, particulates, mercury.
Mining impacts: land degradation, deforestation, water contamination.
Fly Ash: India produces >200 MT annually; disposal remains a challenge.

Measures to Make Coal Power Cleaner

Electrostatic Precipitators (ESPs): Cut particulate emissions.
Flue Gas Desulphurisation (FGD): Reduce SO₂ emissions.
Ultra-Supercritical Technology: Improve efficiency of thermal plants.
Biomass Co-Firing: Blend 5–7% biomass with coal in existing plants.
Fly Ash Utilisation: Use in cement, bricks, and road construction.

Pathways for Transition

Phased Coal Exit, Not Abrupt: Balance energy security with decarbonization.
Just Transition Framework: Reskilling and alternate employment for coal workers.
Accelerate Renewables + Storage: Expand solar, wind, pumped hydro, and battery storage.
Scale Biochar & Biocoal: Support decentralized production and integration in energy/soil systems.
Deploy Carbon Capture (CCUS): In select coal plants to reduce emissions.
Global Climate Finance Push: Advocate for climate justice and financial aid for transition.

Renewable Energy in India: Types, Policies & Emerging Mechanisms

Types of Renewable Energy

Hydropower – Large hydro, small hydro, and pumped storage projects.
Wind Energy – Onshore and offshore wind farms.
Solar Energy – Utility-scale solar parks, rooftop solar, floating solar.
Biomass Energy – Bagasse cogeneration, biogas plants, and waste-to-energy.
Geothermal Energy – Pilot projects in Himalayan and volcanic regions.
Ocean Energy – Tidal, wave, and ocean thermal energy conversion.
Hydrogen (Emerging Clean Fuel) – Green hydrogen from electrolysis, with applications in industry, transport, and energy storage.

Policy Measures & Investment Framework

100% FDI via Automatic Route – Encourages foreign investment in renewables.
Renewable Purchase Obligations (RPOs):
- DISCOMs mandated to procure 43% renewable power by 2029–30.
- Includes 6.5% from hydropower.
Green Energy Corridors:
- 10,000 km of dedicated transmission lines for renewable power evacuation.

Consumer-Centric & Market-Based Mechanisms

PM-KUSUM: Solar pumps and decentralized renewables for farmers.
PM Surya Ghar: Muft Bijli Yojana: Subsidized rooftop solar for households.
Green Term-Ahead Market (GTAM): Trading platform for renewable electricity.
Energy Open Access Rules (2022): Simplifies industrial and consumer procurement of renewable energy.

Innovation & Green Transitions

National Green Hydrogen Mission: Large-scale hydrogen production for industry, mobility, and grid storage.
Small Modular Reactors (SMRs): Advanced nuclear for distributed clean power.
Certification for PV Modules (BIS): Ensures quality and reliability of solar equipment.

Key Themes for Future Growth

Consumer Empowerment – Rooftop solar, solar pumps, and decentralized renewables.
Market Expansion – Green energy trading, carbon markets, and RPO compliance.
Innovation Push – Hydrogen, SMRs, offshore wind, floating solar, advanced storage.
Green Infrastructure – Transmission corridors and EV charging networks.
Quality Standards – Strong BIS certifications for solar and renewable technologies.

Levelized Cost of Energy (LCOE) in India (Approximate, ₹/kWh)

Energy Source	Cost Range (₹/kWh)	Remarks
Solar (PV)	2.5 – 4	Lowest among all sources; rapidly declining due to falling module costs and scale.
Wind (Onshore & Offshore)	2.5 – 7	Onshore cheaper (~~₹2.5–4.5), offshore higher (~~₹5–7) due to technology and cabling costs.
Coal (Thermal Power)	3 – 6 (typical), can rise to 7–8	Still the backbone of grid supply; costs vary by plant age, technology (subcritical vs supercritical), and coal import dependence.
Natural Gas (CCGT)	~5	Limited by domestic gas availability; imported LNG raises costs.
Hydropower	~3	Cost-competitive, but site-specific and limited by geography & social impacts.
Nuclear Power	6 – 8	High upfront capital; low fuel costs, reliable baseload.
Hydrogen (Green, Power-to-Power)	12 – 20	Still very expensive compared to conventional power; expected to fall to ₹4–6 by 2040 with scale & technology.

Key Insights

Solar & Onshore Wind are the cheapest sources today in India.
Coal remains competitive but carries hidden costs (pollution, health, carbon).
Offshore Wind & Nuclear are significantly costlier but provide stable long-term energy.
Hydrogen is currently the most expensive, but strategic for decarbonization of hard-to-abate sectors (steel, shipping, aviation).
Hydro remains cost-effective but is geographically limited.
Natural Gas is transitional, but India’s reliance on imports makes it volatile.

Energy Storage Technologies

Energy storage is critical for balancing intermittent renewable sources like solar and wind, ensuring grid stability and energy security. Below are the major storage technologies:

1. Lithium-Ion Batteries

Working Principle: Movement of lithium ions between anode and cathode during charging/discharging.
Features:
- High energy density.
- Widely used in EVs, portable electronics, and grid-scale storage.
Limitations:
- High cost.
- Dependence on rare metals (lithium, cobalt, nickel).
- Safety concerns (thermal runaway).

2. Sodium-Ion Batteries

Working Principle: Movement of sodium ions between electrodes.
Features:
- Lower cost compared to lithium-ion.
- Abundant raw material (sodium).
Limitations:
- Lower energy density.
- Still in pilot/commercialization phase.

3. Hydrogen Fuel Cells (with Hydrogen Storage)

Working Principle: Hydrogen stored, then combined with oxygen in a fuel cell to produce electricity and water.
Features:
- Suitable for long-term storage and heavy transport.
- Long lifespan compared to batteries.
Limitations:
- Currently high costs.
- Requires hydrogen production, storage, and distribution infrastructure.

4. Metal Hydride Fuel Cells

Working Principle: Hydrogen is stored as metal hydrides, then released as ions for electricity generation in a fuel cell.
Features:
- Safer hydrogen storage option.
- High volumetric energy density.
Limitations:
- Heavy and costly.
- Slower hydrogen release rates.

5. Pumped Hydro Storage

Working Principle: Water is pumped to a higher reservoir during low demand and released to generate electricity when needed.
Features:
- Mature and large-scale technology.
- Provides grid balancing and long-duration storage.
Limitations:
- Location-specific (requires suitable terrain).
- Environmental and displacement concerns.

6. Compressed Air Energy Storage (CAES)

Working Principle: Air is compressed and stored in underground caverns; released to drive turbines when required.
Features:
- Scalable for grid applications.
Limitations:
- Requires suitable geological formations.
- Lower round-trip efficiency (~40–60%).

7. Gravity Storage

Working Principle: Heavy blocks are lifted when energy is abundant and lowered to generate electricity.
Features:
- Simple concept, long lifespan.
Limitations:
- Still experimental, limited efficiency compared to pumped hydro.

8. Molten Salt Thermal Storage

Working Principle: Heat from solar concentrators stored in molten salt, later used to generate steam and electricity.
Features:
- Long-duration storage (hours to days).
- Well-suited for concentrated solar power (CSP) plants.
Limitations:
- High infrastructure cost.
- Requires CSP deployment.

9. Liquid Air Energy Storage

Working Principle: Air is cooled to cryogenic temperatures, stored as a liquid, then expanded to drive turbines.
Features:
- High scalability.
- Zero-emission technology.
Limitations:
- Expensive and less mature.
- Lower efficiency compared to batteries.

10. Supercapacitors

Working Principle: Store energy through electrostatic charge on conductive plates.
Features:
- Extremely fast charging/discharging.
- Very long cycle life (millions of cycles).
Limitations:
- Low energy density.
- Best suited for short bursts of power (e.g., grid frequency regulation, regenerative braking).

Key Takeaways

Short-term storage: Lithium-ion, sodium-ion, supercapacitors.
Medium-term storage: Molten salt, liquid air, CAES.
Long-term storage: Hydrogen fuel cells, pumped hydro, gravity storage.
Mature & scalable today: Lithium-ion and pumped hydro.
Emerging innovations: Gravity storage, liquid air, sodium-ion.

Solar Energy

Definition:
Solar energy harnesses the sun’s radiation using various technologies to produce electricity, heat, or chemical fuels. It is a clean, renewable, and increasingly cost-competitive energy source.

Technologies

Photovoltaic (PV) Systems
- Convert sunlight directly into electricity using semiconductor materials (e.g., silicon).
- Commercial module efficiencies: 15–22%.
- Global installed PV capacity reached ~1,419 GW in 2023.
Concentrated Solar Power (CSP)
- Uses mirrors or lenses to concentrate sunlight, generating high-temperature steam to drive turbines.
- Often paired with thermal storage for dispatchable power supply.
Solar Thermal Systems
- Capture sunlight to heat water or air for space heating, industrial processes, or solar cooking.
- Thermal energy storage allows use during non-sunlight hours.

Emerging Innovations

Floatovoltaics: PV arrays mounted on water surfaces; reduce land use, limit water evaporation, and improve efficiency due to cooling.
Agrivoltaics: Integrating solar panels with crop cultivation to optimize land productivity and provide shade benefits.
Perovskite Solar Cells: Lightweight, flexible, low-cost next-generation semiconductors with potential efficiencies exceeding 25%.

Advantages of Solar Energy ☀️

1. Environmental Benefits

Renewable and inexhaustible source.
Produces no greenhouse gases during operation.
Reduces air and water pollution compared to fossil fuels.

2. Energy Security & Independence

Decreases reliance on imported fossil fuels.
Suitable for decentralized power generation (rooftop systems).

3. Economic Advantages

Falling installation costs due to technological advances.
Creates jobs in manufacturing, installation, and maintenance.
Low operating and maintenance costs after setup.

4. Versatility

Can be deployed at various scales — from small rooftops to large solar farms.
Works in remote/off-grid areas.
Compatible with other systems (e.g., solar + battery storage).

5. Long-Term Reliability

PV panels have long lifespans (20–30 years).
Modular design allows easy expansion.

Disadvantages of Solar Energy 🌥️

1. Weather and Location Dependence

Inefficient in areas with low sunlight or frequent cloud cover.
Seasonal variations affect energy output.

2. Intermittency

No power generation at night.
Requires energy storage systems (batteries, pumped storage) or backup supply.

3. High Initial Investment

Installation costs for panels, inverters, and mounting can be high without subsidies.

4. Space Requirements

Large-scale solar farms require significant land, potentially causing land-use conflicts.

5. Energy Storage Costs

Battery systems are expensive, have limited lifespans, and require disposal/recycling solutions.

6. Manufacturing Impact

PV manufacturing uses energy-intensive processes and hazardous materials (e.g., cadmium, lead in some panels).

7. Efficiency Limits

Commercial PV panels typically have only 15–22% efficiency; a lot of sunlight is unused.

8. Transmission Challenges

Large solar farms in deserts or remote areas require long transmission lines to population centers.

9. Degradation Over Time

Panel efficiency decreases gradually (~0.5–1% per year).

10. Recycling Issues

End-of-life panel recycling is still underdeveloped in many countries, creating potential waste problems.

Solar Energy in India

Solar Technologies

1. Photovoltaic (PV) Technology

Raw Material:
- Begins with metallurgical-grade silicon.
- Processed via the Siemens Process (using HCl) to produce polysilicon.
- Polysilicon → Ingots → Wafers → Doping → Solar Cells → PV Modules.
Global Manufacturing:
- ~97% of polysilicon is made in China.
- ~80% of PV modules also come from China, due to economies of scale.

2. Solar Thermal Power

Working: Mirrors concentrate sunlight to generate heat, which transfers to molten salt → boils water → produces steam → drives turbines to generate electricity.
Advantage: Provides thermal storage for continuous supply.

3. Luminescent Solar Concentrators (LSCs)

Working: Similar to PV, but use total internal reflection to capture light at any angle.
Advantage: More efficient in diffuse light conditions (cloudy or shaded environments).
Emerging Technology: Potentially superior to traditional PV panels.

Major Solar Schemes & Initiatives

National Solar Mission (NSM):
- Original target: 20 GW by 2022.
- Revised: 100 GW solar capacity by 2022 (achieved ~70 GW).
PM-KUSUM Scheme:
- Solar pumps for farmers, decentralised solar generation.
PM Surya Ghar: Muft Bijli Yojana:
- Rooftop solar for households, subsidised/free power.
PLI Scheme for Solar PV Modules:
- Incentivizes domestic manufacturing of high-efficiency solar cells & modules.
Carbon Credit Trading Scheme:
- Monetization of emission reductions.
100% FDI via Automatic Route:
- Encourages foreign investment in solar.

Key Achievements

Bhadla Solar Park (Rajasthan): Largest in the world (~2.25 GW).
Floating Solar Projects: Kayamkulam (Kerala), Ramagundam (Telangana).
Solar Villages: Modhera (Gujarat) – India’s first solar-powered village.
Green Infrastructure:
- Cochin Airport (Kerala): World’s first airport fully powered by solar.
International Solar Alliance (ISA): India-led initiative launched at COP21 (Paris).
Solar Energy Corporation of India (SECI): PSU implementing large solar projects.
Top Solar States: Rajasthan, Gujarat, Tamil Nadu (Tamil Nadu leads in rooftop).

Challenges

Land Availability: Large solar parks need vast land tracts.
Intermittency: Solar is available only during the day; night-time storage is critical.
Import Dependence: Heavy reliance on Chinese polysilicon, cells, and modules.
Waste Management: End-of-life solar panels create e-waste & recycling issues.
Transmission Constraints: Evacuation bottlenecks and grid fluctuations due to intermittent generation.
Cost of Storage: Batteries and other storage technologies remain expensive.

Way Forward

Boost Domestic Manufacturing: Strengthen PLI schemes, create polysilicon & wafer ecosystem in India.
Solar + Storage Integration: Promote hybrid projects (solar + batteries + wind).
Floating & Rooftop Solar Expansion: Reduce land pressure by scaling rooftop and water-based solar.
Recycling Ecosystem: Develop solar panel recycling industry to handle e-waste.
International Collaboration: Leverage the ISA for global partnerships & financing.
Decentralized Solar: Expand solar villages and rural mini-grids for inclusive growth.

2. Wind Energy

Definition:
Wind energy converts the kinetic energy of moving air into electricity using wind turbines. It is one of the fastest-growing renewable energy sources.

Technologies

Onshore Wind Turbines – Land-based; cost-effective and widely deployed.
Offshore Wind Turbines – Installed in shallow or deep waters; benefit from stronger, steadier winds.
Vertical-Axis Turbines – Suitable for urban/low-space areas.

Emerging Innovations

Floating Offshore Wind Farms: Enable deployment in deep waters with stronger winds.
Hybrid Wind-Solar Farms: Share infrastructure to optimize land and grid use.
Airborne Wind Energy Systems: High-altitude kites/tethers for tapping stronger winds.

Merits of Wind Energy 🌬️

1. Renewable and Sustainable

Uses wind, an inexhaustible natural resource.

2. Environmentally Friendly

No greenhouse gas emissions during operation.
Does not consume water for cooling like thermal power plants.

3. Cost-Effective in the Long Run

Low operating and maintenance costs once installed.
Falling cost per kWh with larger, more efficient turbines.

4. Energy Security

Reduces dependence on fossil fuel imports.
Can be deployed in rural/off-grid areas.

5. Land Use Efficiency

Land under turbines can be used for agriculture or grazing.

Demerits of Wind Energy 🌥️

1. Intermittent and Variable

Power output depends on wind speed; no generation in calm weather.

2. Site Specificity

Requires locations with consistent, strong winds; limited in some regions.

3. Noise and Aesthetic Concerns

Turbines generate noise and can alter landscape views.

4. Impact on Wildlife

Risk of bird and bat collisions with turbine blades.

5. High Initial Cost

Installation and grid connection can be expensive.

6. Space Requirements

Large wind farms need significant spacing between turbines.

7. Grid Integration Challenges

Requires balancing and backup power due to variability.

Wind Energy: Status, Potential, Challenges and the Road Ahead

Current Status

India is the third-largest wind power producer globally, with an installed capacity of 48 GW.
Raw Material Dependence: Around 80% of critical components are imported, mainly from China and Turkey.
Domestic Manufacturing: Currently, India has indigenous capability only in gearbox manufacturing.
Turbine Heights:
- Older models: ~80–100 meters (equivalent to 5–6 storey buildings).
- Modern designs: up to 120–150 meters, capturing stronger and steadier winds.
Institutional Support: The National Institute of Wind Energy (NIWE) provides R&D, certification, and policy advice.

Geographical Distribution

Current Installations: Tamil Nadu and Gujarat are the leading wind energy hubs.
High Potential States: Andhra Pradesh, Gujarat, Karnataka, and parts of Tamil Nadu.

Resource Potential

At 120 m hub height: ~700 GW.
At 150 m hub height: ~1160 GW.
Current installed base (48 GW) represents only a fraction of this potential.

Technology Upgradation

Repowering: Replacing old, small-capacity turbines (~250–500 kW, >15 years old) with modern multi-MW turbines.
Life Extension: Extending operational life by upgrading turbine height, blades, and key components.
Scaling Capacity: Proposal for 50 GW of additional capacity in coastal Gujarat (CTN region).

Policy Landscape

National Offshore Wind Energy Policy (2015): Announced, but large-scale implementation is pending.
National Wind-Solar Hybrid Policy (2018): Promotes hybrid projects for optimal resource utilization.
Proposed National Wind Energy Mission: Targets 140 GW by 2030.

Offshore Wind: Potential & Challenges

Advantages:

Consistent and stronger wind speeds compared to onshore.
Unlocks vast potential without competing for land.

Challenges:

High Initial Costs: Offshore projects cost 2–3 times more than onshore.
Technological Complexity: Turbines must withstand saltwater corrosion and rough seas.
Environmental Regulations: Sensitive marine and coastal ecosystems.
Complex Logistics: Transport and installation of giant turbines in deep waters.
Grid Integration: Requires costly undersea cabling and substations.
Financing Risks: Long payback periods deter investors.
Operations & Maintenance: Costlier due to difficult sea access.

Onshore Wind Challenges

Land Acquisition: High population density and competing land use.
Grid Connectivity: Curtailments in wind-rich states due to transmission bottlenecks.
Intermittency: Variable wind supply needs storage or hybrid integration.
Domestic Manufacturing Gaps: Reliance on imports for blades, generators, and control electronics.
Repowering Barriers: Financial hurdles and land rights issues for upgrading old wind farms.

Way Forward

Boost Domestic Manufacturing – Incentivize local production of blades, nacelles, and generators.
Wind-Solar-Battery Hybrids – Combine resources to ensure 24×7 renewable supply.
Accelerated Repowering – Modernize old wind farms with higher-capacity turbines.
Strengthen Transmission – Expand Green Energy Corridors for evacuation.
Pilot Offshore Projects – Start with Gujarat & Tamil Nadu coasts before scaling.
Financial Innovations – Use green bonds, viability gap funding, and concessional loans.
Robust Policy Support – Launch the National Wind Energy Mission with clear targets and state-level action.
R&D & Innovation – Taller towers, lightweight blades, AI-driven predictive maintenance, and floating offshore wind for deep waters.

3. Hydropower

Definition:
Hydropower generates electricity by converting the energy of flowing or falling water into mechanical power for turbines.

Technologies

Reservoir (Dam) Plants – Store water in large dams for controlled release and power generation.
Run-of-the-River Plants – Use natural river flow with minimal storage; lower ecological impact.
Pumped Storage Hydropower – Stores energy by pumping water to a higher reservoir for later release.

Emerging Innovations

Small & Micro Hydro Systems: Provide local power with minimal environmental footprint.
Fish-Friendly Turbines: Reduce harm to aquatic life.
Digital Monitoring & Automation: Improves efficiency and safety.

Merits of Hydropower 💧

1. Renewable and Sustainable

Uses the natural water cycle, replenished by rainfall and snowmelt.

2. Clean Energy Source

No direct greenhouse gas emissions during operation.

3. Reliable and Flexible

Can provide both base-load and peak-load power.
Fast start-up and shut-down times for grid balancing.

4. Multi-Purpose Benefits

Supports irrigation, flood control, navigation, and water supply.

5. Long Plant Lifespan

Hydropower plants can operate for decades with proper maintenance.

6. Low Operating Costs

Once built, operation and maintenance costs are relatively low.

Demerits of Hydropower ⚠️

1. High Initial Cost

Dams and associated infrastructure are expensive to build.

2. Environmental Impact

Alters river ecosystems, blocks fish migration, and floods habitats.

3. Social Displacement

Large projects can displace communities and submerge fertile land.

4. Risk of Siltation

Sediment buildup reduces reservoir capacity and efficiency.

5. Vulnerability to Climate Change

Droughts and changing rainfall patterns can reduce output.

6. Safety Risks

Dam failures can cause catastrophic flooding.

4. Biomass Energy

Definition:
Biomass energy uses organic materials (plant matter, agricultural residues, wood, waste) to produce heat, electricity, or biofuels.

Technologies

Direct Combustion: Burns biomass for heat and steam generation.
Anaerobic Digestion: Converts organic waste into biogas (methane + CO₂).
Gasification & Pyrolysis: Produces syngas or bio-oil for power and fuel.

Emerging Innovations

Algae-Based Biofuels: High-yield, low-land-use fuel production.
Advanced Pelletization: Improves energy density and transport efficiency.
Carbon-Negative Bioenergy (BECCS): Combines biomass with carbon capture for negative emissions.

5. Geothermal Energy

Definition:
Geothermal energy taps heat from the Earth’s crust to generate electricity or provide direct heating.

Technologies

Dry Steam Plants: Use natural steam from geothermal reservoirs.
Flash Steam Plants: Convert high-pressure hot water to steam.
Binary Cycle Plants: Use lower-temperature heat with a secondary fluid to drive turbines.

Emerging Innovations

Enhanced Geothermal Systems (EGS): Create artificial reservoirs in hot, dry rock areas.
Hybrid Geothermal-Solar Plants: Improve year-round efficiency.
Low-Temperature Geothermal for Heating: Expands use in non-volcanic regions.

Merits of Geothermal Energy 🌋

1. Renewable and Sustainable

Utilizes Earth’s internal heat, which is virtually inexhaustible on a human timescale.

2. Clean and Low-Emission

Very low greenhouse gas emissions compared to fossil fuels.

3. Reliable and Consistent

Provides base-load power 24/7, unaffected by weather or seasonal changes.

4. High Energy Efficiency

Geothermal power plants can achieve high capacity factors (up to 90%).

5. Low Operating Costs

After initial setup, running costs are minimal.

6. Small Land Footprint

Requires less surface area compared to solar or wind farms.

Demerits of Geothermal Energy ⚠️

1. Location-Specific

Feasible mainly in tectonically active regions (volcanic zones, hot springs).

2. High Initial Cost

Drilling deep wells and installing infrastructure is expensive.

3. Risk of Resource Depletion

Overuse can cool down reservoirs over time if not managed.

4. Possible Environmental Impacts

Risk of land subsidence.
Release of small amounts of greenhouse gases (CO₂, H₂S) from underground.

5. Technical Challenges

Drilling into hard rock and high temperatures requires advanced technology.

6. Induced Seismicity

Enhanced Geothermal Systems (EGS) may trigger minor earthquakes

Green Hydrogen

Applications

Fuel for Cryogenic Engines – Space exploration.
Hydrogen Fuel Cells – For clean electricity generation.
Nuclear Fuel in ITER – Fusion energy research.
Aviation and Heavy Transport – Trucks, ships, and aircraft.
Industrial Use – Cement, steel, and chemical production.
Long-Term Energy Storage – Ensures grid stability.
Residential & Commercial Use – Cooking stoves and heating.

Key Benefit: Produces only water as residue and has a higher calorific value compared to fossil fuels.

Production of Hydrogen

Steam Methane Reformation (CH₄):
- Grey Hydrogen – without carbon capture.
- Blue Hydrogen – with carbon capture and storage (CCS).
Electrolysis of Water:
- Powered by renewable energy → Green Hydrogen.
- Powered by nuclear → Pink Hydrogen.
- Powered by solar → Yellow Hydrogen.
- Powered by coal → Black Hydrogen.
- Powered by lignite → Brown Hydrogen.

Electrolysis Technologies:

Alkaline Electrolysis
Proton Exchange Membrane (PEM) Electrolysis
Solid Oxide Electrolysis

National Green Hydrogen Mission (India) – 2030 Goals

Produce at least 5 MMT/annum of green hydrogen (equivalent to 125 GW of energy).
Reduce 50 MMT of CO₂ emissions annually.
Mobilize ₹8 Lakh Crore investment.
Cut fossil fuel imports by ₹1 Lakh Crore.
Create 6 Lakh jobs.

Projections:

By 2050, demand is expected to reach 28 MMT (to meet ~80% of requirements).
Current demand stands at 6 MMT.
Government support: ₹20,000 Crore allocation by the Ministry of New & Renewable Energy.

SIGHT Program

Focus: Domestic manufacturing of electrolysers.
Phase I (till 2026): Hydrogen adoption in existing sectors (refineries, fertilizers).
Phase II: Expansion into steel, mobility (shipping, aviation, railways).

Cost Outlook

Current cost: $5/kg
Target: $1.5/kg

Challenges

Storage Issues – low energy density, high-pressure tanks, cryogenic storage, hydrogen leakage.
Transportation Barriers – embrittlement in pipelines, cryogenic transport challenges.
High Production Cost – renewables-based electrolysis is capital-intensive.
Energy Efficiency Losses – multiple conversion steps reduce efficiency (~30–40%).
Infrastructure Gaps – lack of pipelines, refueling stations, and supply chains.
Safety Concerns – highly flammable, invisible flame, explosion risk.
Water Dependency – 9 liters of purified water per kg H₂ (a concern in water-stressed regions).
Technology Maturity – electrolyzers, storage systems, and fuel cells still need scaling.
Economic Viability – industries may find fossil fuels cheaper unless incentives are strong.
Policy & Market Uncertainty – lack of global pricing mechanisms and standards.

Global Context

EU Hydrogen Strategy: 40 GW electrolyzers by 2030.
Japan & South Korea: Hydrogen-powered mobility (cars, ships).
Middle East: Large-scale hydrogen exports using solar & wind.
Australia: Green hydrogen export hubs (to Asia).
USA (Inflation Reduction Act): Tax credits for green hydrogen production.

Way Forward / Solutions

Ammonia & Methanol as Carriers
- Hydrogen can be converted to ammonia or methanol for easier storage/transport, then reconverted.
Blending with Natural Gas
- Short-term solution: mix hydrogen into existing gas pipelines (up to 20%).
Scaling Renewable Energy
- Dedicated solar/wind capacity for large-scale electrolysis.
Cost Reduction via Innovation
- New electrolyzer technologies, economies of scale, and automation.
Water Management
- Use of seawater electrolysis, wastewater recycling, and desalination technologies.
Infrastructure Development
- Hydrogen refueling stations, pipelines, and global trade networks.
Safety Standards & Regulations
- Strict protocols for handling, storage, and transport.
International Collaboration
- Hydrogen trade corridors (India–Japan, EU–North Africa, Gulf–Asia).
- Standardization of certifications (“green” hydrogen guarantees).
Policy Incentives
- Carbon pricing, subsidies, and tax credits to make hydrogen competitive.
R&D and Skill Development

Investment in advanced materials, catalysts, storage solutions.
Training workforce for hydrogen economy jobs.

Bioenergy and Biofuels in India

What is Bioenergy?

Bioenergy is energy derived from biomass (organic material such as crops, residues, algae, or waste).
It provides multiple forms of fuel for power, heat, transport, and industry.

Types of Biofuels

Biogas – via biogasification of organic matter (anaerobic digestion).
Biomethane – via biomethanation, purified biogas (CH₄-rich).
Syngas – via plasma arc gasification, mixture of CO + H₂.
Biochar – via pyrolysis, acts as a carbon sink & soil enhancer.
Bioethanol – via fermentation of sugars/starch.
Biodiesel – via transesterification of vegetable oils, animal fats, or used cooking oil.

Generations of Biofuels

First Generation (Edible sources):
- Sugarcane, corn, vegetable oils.
- Issue: Food vs fuel conflict.
Second Generation (Non-edible sources):
- Jatropha, waste cooking oil, crop residues, lignocellulosic biomass.
- Advantage: Avoids food competition.
Third Generation (Algae / Microbes):
- Algae-derived biofuels (high yield per hectare).
- Challenge: High production cost, scalability.
Fourth Generation (Genetically Engineered Crops/Microbes):
- Engineered microbes for enhanced yield & carbon capture.
- Future Potential: Sustainable, scalable, carbon-negative fuels.

Government Measures & Initiatives

MoJS – Gobar Dhan Initiative
- “Waste to Wealth” program promoting biogas & biochar production from cattle dung and organic waste.
Mo Power – SAMARTH Scheme
- Promotes biomass co-firing (5–7%) in coal-based thermal power plants.
Mo Petroleum & Natural Gas – PM JI-VAN Yojana (till 2023)
- Promotes 2G ethanol plants using agri-residues & lignocellulosic biomass.
- Encourages blending with petrol/diesel/SAF (Sustainable Aviation Fuel).
National Biofuel Policy (2018)
- Expanded feedstock list for ethanol production.
- Promotes 1G, 2G, and advanced biofuels.
- Financial support for bio-refineries.

Targets & Progress

E20 Blending Target: 20% ethanol blending in petrol by 2025.
Current Status: ~18% achieved (as of 2023).
Required Production: ~1500 crore litres by 2025.
Vehicle Compatibility: BS VI vehicles designed for E20 blends.
Flex Fuel Vehicles (FFVs): Can run on 0–100% ethanol (Toyota & others developing models).

Advantages of Biofuels

Carbon Neutrality: Biomass absorbs CO₂ during growth, offsetting emissions during combustion.
Energy Security: Reduces fossil fuel imports (India spends ₹8–9 lakh crore annually).
Rural Economy: Generates rural employment via crop residue utilization.
Waste Management: Converts waste cooking oil, residues, dung into fuel.
Versatility: Can replace petrol, diesel, LPG, and coal in different applications.

Challenges

Feedstock Availability: Seasonal, scattered biomass supply chains.
Food vs Fuel Conflict: Use of sugarcane & corn for ethanol may impact food prices.
Logistics & Collection Costs: Transporting bulky biomass is expensive.
High Production Costs: Especially for 2G, 3G, and 4G biofuels.
Technology & Scale Gaps: Many projects remain pilot-scale.
Policy Uncertainty: Frequent revisions discourage private investment.

Way Forward

Strengthen 2G Ethanol: Scale up crop residue-to-ethanol plants to reduce stubble burning.
Support Advanced Biofuels (3G & 4G): R&D funding for algae and engineered microbes.
Supply Chain Development: Farmer cooperatives & decentralized biomass collection.
Incentivize Flex-Fuel Vehicles: Mandates and subsidies for auto industry to roll out FFVs.
Blending Diversification: Beyond petrol — encourage bio-CNG, biodiesel, and SAF adoption.
International Collaboration: Joint research and funding for advanced biofuel technologies.