BharatNotes
Overview
Hydrogen is the universe's most abundant element but is almost never found in pure form on Earth — it must be produced from other sources. The method of production determines both the cost and the carbon footprint, which is why hydrogen is colour-coded. Green hydrogen, produced using renewable electricity, is the only form that can genuinely decarbonise hard-to-abate sectors such as steel, cement, fertilisers, shipping, and aviation — sectors that cannot easily be electrified directly. India approved its National Green Hydrogen Mission in January 2023, targeting 5 MMT (million metric tonnes) annual production by 2030. For UPSC, this topic spans GS3 (Science & Technology, Energy, Environment, Economy) and tests understanding of chemistry, policy, and India's clean-energy ambitions.
Types of Hydrogen by Production Method
Hydrogen is assigned informal colour codes that describe its feedstock and carbon intensity.
| Colour | Production Method | Carbon Footprint | Status |
|---|---|---|---|
| Grey | Steam Methane Reforming (SMR) of natural gas; CO₂ released into atmosphere | ~10–13 kg CO₂/kg H₂ | Most common today (~95% of global supply) |
| Brown/Black | Coal gasification (brown = lignite; black = bituminous); highly carbon-intensive | Highest of all — up to 20 kg CO₂/kg H₂ | Still used in industrial processes |
| Blue | SMR of natural gas + Carbon Capture and Storage (CCS); CO₂ captured underground | ~2–8 kg CO₂/kg H₂ (depends on CCS efficiency) | Transitional option; debated |
| Turquoise | Methane pyrolysis — thermal decomposition of methane producing H₂ + solid carbon (no CO₂ gas released) | ~3–6 kg CO₂-eq/kg H₂ | Emerging; solid carbon used in tyres, soil amendment |
| Green | Water electrolysis powered by renewable electricity (solar/wind); no direct CO₂ | Near zero (~0.5–1 kg CO₂-eq/kg H₂) | Priority for decarbonisation |
| Pink/Red | Electrolysis powered by nuclear energy | Low carbon, but nuclear debate | Limited deployment |
Key distinction for UPSC: Only green hydrogen is produced without any fossil fuel input in the energy supply. Blue hydrogen retains upstream methane leakage risks. Turquoise hydrogen avoids gaseous CO₂ but requires very high temperatures.
Why Green Hydrogen Matters — Hard-to-Abate Sectors
Direct electrification (via batteries and EVs) can address transportation and some industrial heat, but certain sectors are extremely difficult to decarbonise without green hydrogen:
| Sector | Why Hydrogen Is Needed | Use Case |
|---|---|---|
| Steel | Blast furnaces use coal (coke) as both fuel and reducing agent; hydrogen can replace coke in Direct Reduced Iron (DRI) | Green steel via H₂-DRI process |
| Cement | Very high kiln temperatures needed; CO₂ also released from limestone calcination | Hydrogen for high-heat; combined with CCS |
| Fertilisers (Ammonia) | Ammonia (NH₃) is made via Haber-Bosch process using grey hydrogen from natural gas | Green ammonia = green H₂ + N₂ from air |
| Shipping | Long-range vessels cannot carry enough batteries; hydrogen or ammonia as marine fuel | Green ammonia or liquid hydrogen fuel |
| Aviation | Same energy-density constraint; liquid hydrogen or sustainable aviation fuel (SAF) via hydrogen | Hydrogen-powered aircraft in development |
| Long-duration energy storage | Hydrogen stores renewable energy for weeks/seasons, unlike batteries | Power-to-gas-to-power cycle |
India's fertiliser sector is a particular priority — the country is the world's second-largest ammonia consumer, and almost all of it is currently produced from grey hydrogen using imported natural gas.
Electrolysis Technology — How Green Hydrogen Is Made
Electrolysis splits water (H₂O) into hydrogen (H₂) and oxygen (O₂) using electricity. The key is that the electricity must come from renewable sources for the hydrogen to be "green."
Basic reaction: 2H₂O → 2H₂ + O₂
Electrolyser Types
| Parameter | Alkaline Electrolyser (AE) | PEM Electrolyser | Solid Oxide Electrolyser (SOEC) |
|---|---|---|---|
| Electrolyte | Liquid potassium hydroxide (KOH) solution | Solid proton-exchange membrane (Nafion) | Solid ceramic oxide |
| Operating temperature | 60–90°C | 50–80°C | 675–825°C |
| Efficiency (kWh/kg H₂) | ~50–55 kWh/kg | ~50–55 kWh/kg | ~35–45 kWh/kg (10–26% more efficient) |
| Suitability | Stable grid power; industrial scale; cheapest | Intermittent renewables (variable load); fast response | Waste industrial heat; highest efficiency |
| Maturity | Commercial; most widely deployed | Commercial; growing rapidly | Pre-commercial/demonstration phase |
| India relevance | Target for PLI under SIGHT scheme | Also targeted under SIGHT | Future technology |
SOEC advantage: Because it operates at high temperature, less electrical energy is needed — some energy comes from heat, making it the most efficient electrolysis technology. However, material degradation at high temperatures is a key challenge.
Hydrogen Storage and Transport
After production, hydrogen must be stored and transported — a significant engineering challenge because H₂ is the lightest molecule:
| Method | How It Works | Energy Density | Challenges |
|---|---|---|---|
| Compressed gas | High-pressure tanks at 350–700 bar | Low volumetric density | Tank weight; safety; infrastructure cost |
| Liquid hydrogen | Cooled to −253°C (cryogenic) | Higher volumetric density | Significant energy for liquefaction (~30% of energy content); boil-off losses |
| Ammonia (NH₃) carrier | H₂ converted to ammonia for shipping; reconverted at destination | High energy density; existing infrastructure | Reconversion ("cracking") adds cost; toxicity |
| Liquid Organic Hydrogen Carriers (LOHC) | Hydrogen chemically bonded to organic molecules (e.g., toluene → methylcyclohexane) | Moderate | Hydrogenation and dehydrogenation costs |
| Metal hydrides | H₂ absorbed into metal alloys | Very high (by weight) | Weight, slow kinetics, cost |
| Pipeline | Dedicated H₂ pipelines or blending into existing natural gas networks | N/A | Embrittlement of existing gas pipes; safety codes |
India's transport challenge: India lacks a hydrogen pipeline network. Initial strategy focuses on producing green hydrogen at coastal locations for export (as liquid H₂ or green ammonia via ships) or for use at the production site (captive industrial use).
India's National Green Hydrogen Mission (NGHM)
Approved: January 4, 2023, by the Union Cabinet chaired by PM Narendra Modi.
Nodal Ministry: Ministry of New and Renewable Energy (MNRE).
Key Targets by 2030
| Target | Value |
|---|---|
| Green hydrogen production capacity | At least 5 MMT per annum |
| Associated renewable energy capacity addition | ~125 GW |
| Electrolyser manufacturing capacity | ~15 GW per annum |
| Investment expected | Over Rs 8 lakh crore |
| Employment generation | Over 6 lakh jobs |
| CO₂ mitigation | ~50 MMT per annum |
| Reduction in fossil fuel imports | ~Rs 1 lakh crore per annum |
Budget Outlay
Total initial outlay: Rs 19,744 crore, distributed as:
| Component | Allocation |
|---|---|
| SIGHT programme (electrolyser manufacturing + green H₂ production incentives) | Rs 17,490 crore |
| Pilot projects (steel, shipping, transport, other sectors) | Rs 1,466 crore |
| R&D and innovation | Rs 400 crore |
| Other mission components | Rs 388 crore |
SIGHT Scheme — Strategic Interventions for Green Hydrogen Transition
SIGHT is the flagship incentive programme under NGHM with two distinct financial mechanisms:
Component A — Incentives for domestic electrolyser manufacturing:
- PLI-style incentive of up to Rs 4,440/kW of electrolyser capacity manufactured
- Target: 1,500 MW tender launched by SECI (Solar Energy Corporation of India) for electrolyser manufacturing capacity
Component B — Incentives for green hydrogen production:
- Incentive of up to Rs 50/kg for green hydrogen produced
- Designed to bridge the gap between current production cost (~$4–6/kg) and target cost
Cost trajectory: The mission expects to bring down the cost of green hydrogen from the current ~$4–6/kg to approximately $1.5/kg by 2030 (the Rs 50/kg incentive narrows the gap while economies of scale build up). Reaching $1/kg by 2030 is considered unlikely without major global technology breakthroughs.
Key Institutional Roles
| Institution | Role |
|---|---|
| MNRE | Nodal ministry; overall policy and target-setting |
| IREDA (Indian Renewable Energy Development Agency) | Financing green hydrogen and electrolyser projects |
| SECI (Solar Energy Corporation of India) | Tendering for electrolyser manufacturing capacity and green H₂ production |
| NTPC | Pilot green hydrogen projects (e.g., Leh, Rajasthan) |
| ONGC, IOC | Exploring green H₂ for refinery use |
| Railway Ministry | Hydrogen-powered train pilots |
Green Hydrogen Hubs
The mission envisages designation of Green Hydrogen Hubs — regions with high renewable energy potential and proximity to industrial or export facilities — for concentrated development. Potential hub locations include:
- Coastal Andhra Pradesh / Odisha — solar potential + ports for export
- Rajasthan / Gujarat — very high solar irradiance; land availability
- Ladakh / Himalayan region — hydropower-powered green hydrogen
Hydrogen Fuel Cells and Transportation
A Hydrogen Fuel Cell works like a reverse electrolyser — it combines H₂ and O₂ to produce electricity and water:
H₂ + ½O₂ → H₂O + Electricity + Heat
FCEV (Fuel Cell Electric Vehicle) advantages over BEV: longer range (600–800 km), faster refuelling (~5 minutes), better performance in cold weather. India has:
- KPIT Technologies and Tata Motors exploring FCEV buses
- NTPC hydrogen refuelling station pilot in Delhi
- Indian Oil Corporation (IOC) pilot FCEV in Delhi (Toyota Mirai)
Green Ammonia — Fertiliser Sector Transformation
India is the world's second-largest fertiliser consumer. The Haber-Bosch process (N₂ + 3H₂ → 2NH₃) currently uses grey hydrogen. Replacing it with green hydrogen would create green ammonia, dramatically cutting emissions from the fertiliser value chain.
- FACT (Fertilisers and Chemicals Travancore) and NFL (National Fertilizers Ltd) have initiated plans to integrate green ammonia
- India's goal: supply green ammonia to South Korea, Japan, and European markets which have committed to green ammonia imports
Global Context
| Country/Bloc | Strategy |
|---|---|
| European Union | EU Hydrogen Strategy (2020) — 40 GW electrolyser capacity by 2030; import 10 MT green H₂/year |
| USA | Inflation Reduction Act (IRA) — $3/kg production tax credit for clean hydrogen (the "H₂ PTC") for projects starting by 2033 |
| Japan | Basic Hydrogen Strategy — 3 MMT demand by 2030, 20 MMT by 2050; major importer; MoUs with India |
| South Korea | Hydrogen Economy Roadmap — 526,000 FCEVs by 2030 |
| Australia | National Hydrogen Strategy — major export ambitions; partnering with India |
| Saudi Arabia | NEOM green hydrogen project — world's largest planned green H₂ project |
India's competitive advantage lies in its combination of high solar irradiance, falling renewable energy costs, large existing chemical industry infrastructure, and a skilled engineering workforce.
Challenges
- High production cost: Green hydrogen currently costs $4–6/kg vs. grey hydrogen at ~$1.5–2/kg
- Electrolyser manufacturing: India's current domestic electrolyser capacity is nascent; most components imported from China and Europe
- Storage and transport infrastructure: No dedicated hydrogen pipeline network exists
- Safety and standards: Hydrogen codes and standards (BIS) need development for storage, transport, and end-use
- Water requirement: Green hydrogen production via electrolysis requires large volumes of pure water — a concern in water-scarce regions
- Skilled workforce: Specialised training required across the value chain
Exam Strategy
For Prelims: Focus on colour codes (grey/blue/green/turquoise), the exact NGHM targets (5 MMT, 125 GW, Rs 19,744 crore), SIGHT scheme components, and which sectors are "hard-to-abate." Hydrogen colours, electrolyser types, and the distinction between SOEC/PEM/alkaline are direct MCQ material.
For Mains: GS3 questions on clean energy and decarbonisation often ask: (a) why green hydrogen is necessary alongside EVs, (b) India's strategy and challenges, (c) global race for green hydrogen leadership. Use the "hard-to-abate sectors" framing as an analytical anchor. Link to fertiliser import dependence and India's energy security goals. Connect IREDA/SIGHT to PLI policy architecture used elsewhere in India's industrial policy.
Key linkages: EVs + green hydrogen = two-pronged decarbonisation; National Hydrogen Mission links to India's NDC (Nationally Determined Contribution) targets under Paris Agreement; green ammonia connects to food security via fertilisers; export of green hydrogen connects to foreign exchange and energy geopolitics.
Previous Year Questions (PYQs)
Prelims
- Hydrogen fuel cells generate electricity through which reaction? (UPSC CSP 2019 — chemistry of fuel cells)
- With reference to "hydrogen economy," which statements are correct? (UPSC CSP 2023)
Mains
- "India's National Green Hydrogen Mission is as much an economic opportunity as an environmental imperative." Discuss the mission's targets, challenges, and potential for transforming India's energy and industrial landscape. (GS3, 250 words)
- What are "hard-to-abate sectors"? Why is green hydrogen considered essential for decarbonising them when direct electrification is insufficient? (GS3, 150 words)
- Distinguish between grey, blue, and green hydrogen. Evaluate India's comparative advantage in becoming a global green hydrogen exporter. (GS3, 200 words)
