Green Hydrogen: Production, Electrolyser Technology and Applications
An Emerging Pillar of India’s Clean Energy Transition
Green hydrogen is an important emerging technology for reducing emissions in industries and transport sectors where direct electrification can be difficult. It is produced by splitting water using electricity from renewable sources such as solar and wind power.
Green hydrogen is an energy carrier produced through a low-emission pathway. Renewable electricity supplies the energy required to separate hydrogen from water.
1. What Is Green Hydrogen?
Hydrogen is an energy carrier, not a primary energy source that is generally available in large quantities in pure form. It must be produced from compounds such as water or natural gas. Its environmental impact depends on the method of production and the emissions associated with the complete production process.
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☀️Renewable Electricity Solar and wind power supply electricity for electrolysis. |
💧Purified Water Water provides the hydrogen and oxygen separated during electrolysis. |
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⚡Energy Storage Hydrogen stores energy in chemical form for later use. |
🏭Industrial Applications It can replace fossil-based hydrogen in selected industrial processes. |
2. How Is Green Hydrogen Produced?
The main process shown in the supplied infographic is water electrolysis. An electrolyser uses electricity to split water into hydrogen and oxygen.
Renewable Electricity
Water Treatment
ELECTROLYSER
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O₂ Oxygen Anode (+) |
H₂ Hydrogen Cathode (−) |
The reaction requires electrical energy. When the electricity comes from qualifying renewable sources and the production pathway meets the relevant emissions criteria, the hydrogen can qualify as green hydrogen.
3. Understanding the Electrolyser
An electrolyser is the central equipment used in water electrolysis. The anode and cathode support different electrochemical reactions, while the separator or membrane helps keep the product gases apart.
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O₂
ANODE (+)
Oxygen production
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H₂
CATHODE (−)
Hydrogen production
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| Component | Main Function |
|---|---|
| Anode | Produces oxygen. |
| Cathode | Produces hydrogen. |
| Electrolyte | Supports ionic conduction in applicable systems. |
| Membrane | Separates the gases and allows required ion transport. |
| Power Supply | Provides energy to drive electrolysis. |
4. Green Hydrogen vs Conventional Hydrogen
| Basis | Green Hydrogen | Fossil-Based Hydrogen |
|---|---|---|
| Production | Water electrolysis using renewable electricity | Commonly produced from fossil fuels |
| Emissions | Potentially lower | Generally higher without effective controls |
| Main consideration | Renewable power and lifecycle emissions | Fossil fuel use and emissions management |
5. India's Green Hydrogen Standard
India's Ministry of New and Renewable Energy notified the Green Hydrogen Standard in August 2023. The standard defines an emissions ceiling for hydrogen to qualify as green.
Well-to-gate assessment considers emissions associated with production up to the defined production-gate boundary. Renewable electricity alone does not mean that every stage of the production chain has zero emissions.
6. Major Applications of Green Hydrogen
🌾 Fertilisers and Green Ammonia
Green hydrogen can replace fossil-based hydrogen used to manufacture ammonia, a key input for nitrogen fertilisers.
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🏭 Petroleum Refineries
Hydrogen is used for sulphur removal and other refining processes. A green supply can reduce associated emissions.
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🔩 Iron and Steel
Hydrogen can act as a reducing agent in direct reduced iron production, potentially replacing some coal-based processes.
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🚚 Road and Rail Transport
Fuel cells convert hydrogen into electricity for electric motors in suitable buses, trucks and trains.
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🚢 Shipping
Green ammonia and green methanol derived from hydrogen may provide alternative marine fuels.
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🌍 Exports and Energy Storage
Hydrogen and its derivatives can serve export markets and help store energy for later use.
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7. Electrolyser vs Fuel Cell
| Feature | Electrolyser | Fuel Cell |
|---|---|---|
| Input | Electricity and water | Hydrogen and oxygen |
| Output | Hydrogen and oxygen | Electricity, water and heat |
| Purpose | Produces hydrogen | Generates electricity |
8. National Green Hydrogen Mission
India's National Green Hydrogen Mission was approved in January 2023 with an outlay of ₹19,744 crore. Implemented by MNRE, it aims to expand production, support domestic manufacturing and develop India's hydrogen ecosystem.
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5 MMT
Annual Production Target
At least 5 million metric tonnes per year by 2030
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₹19,744 Cr
Mission Outlay
Approved in January 2023
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SIGHT
Incentive Programme
Supports electrolyser manufacturing and hydrogen production.
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R&D
Research and Innovation
Supports technology, testing, safety and pilot projects.
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| Indicator | Reported Figure |
|---|---|
| Electrolyser manufacturing capacity awarded incentives | 3,000 MW/year |
| Commissioned hydrogen capacity, by February 2026 | About 8,000 tonnes/year |
| Hydrogen production capacity awarded incentives | 8,62,000 tonnes/year |
| Hydrogen mobility pilot vehicles | 70 vehicles |
9. Benefits and Challenges
✓ Benefits
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! Challenges
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Green hydrogen is not automatically the best choice for every energy application. It is especially relevant where direct electrification is difficult or hydrogen already serves as an industrial feedstock. Its overall benefits depend on production costs, energy efficiency, infrastructure and lifecycle emissions.
Key Takeaways
- Green hydrogen is produced using renewable electricity and water electrolysis.
- Hydrogen forms at the cathode and oxygen forms at the anode.
- Purification, gas separation and storage are essential parts of the process.
- Major applications include fertilisers, refineries, steel, transport and shipping.
- India's standard sets an emissions ceiling of 2 kg CO₂-equivalent per kg of hydrogen, on a well-to-gate basis averaged over 12 months.
- India targets at least 5 MMT of annual green hydrogen production capacity by 2030.
References
1. Press Information Bureau — National Green Hydrogen Mission
2. MNRE — National Green Hydrogen Mission Document
3. Ministry of New and Renewable Energy — National Green Hydrogen Mission
