Question: Electrolyser technologies for Green Hydrogen production — types, characteristics, and policy significance under India's Green Hydrogen Mission
Introduction
Green Hydrogen, produced via electrolysis using renewable energy, is central to India's decarbonisation strategy. The choice of electrolyser technology directly determines efficiency, cost, and scalability of the entire value chain.
Body
1. Alkaline Electrolysers — Proven but Inflexible
Alkaline electrolysers use a liquid potassium hydroxide solution as electrolyte and represent the most commercially mature technology. Their lower capital cost makes them attractive for large-scale deployment, but they respond poorly to fluctuating renewable power inputs, limiting integration with solar and wind sources.
2. PEM Electrolysers — Flexible and Compact
Proton Exchange Membrane electrolysers employ a solid polymer electrolyte, enabling rapid response to variable renewable power — a critical advantage for grid-coupled green hydrogen plants. They produce high-purity hydrogen and have a compact footprint, though their reliance on platinum-group metal catalysts raises cost concerns for large-scale adoption.
3. Solid Oxide Electrolysers — High Efficiency, Emerging Stage
SOECs operate at temperatures exceeding 700°C, allowing them to utilise waste industrial heat and achieve the highest theoretical efficiency among current electrolyser types. However, they remain at a pre-commercial stage due to material durability challenges and thermal cycling constraints.
4. Policy Context — National Green Hydrogen Mission
India's National Green Hydrogen Mission targets significant domestic electrolyser manufacturing capacity alongside green hydrogen production. The mission incentivises technology-agnostic deployment, recognising that alkaline and PEM technologies will dominate near-term scale-up while SOEC matures for industrial heat integration.
Conclusion
No single electrolyser technology is universally superior; each suits distinct operational contexts. Effective policy must support a diversified technology portfolio, domestic manufacturing incentives, and R&D investment to drive down costs across all three pathways.
Word count: 230
PYQ 2026
Which of the following statements with regard to Green Hydrogen is/are correct?
1. It is decarbonized hydrogen obtained from natural gas reforming combined with carbon capture and storage (CCS).
2. It is produced using electrolysis of water with electricity generated by renewable energy.
3. National Green Hydrogen Mission of India aims for abatement of nearly 50 MMT of annual greenhouse gas emissions by 2030.
Select the answer using the code given below:
PYQ
With reference to the National Green Hydrogen Mission (NGHM) of India, which of the following statements is/are correct?
1. The Mission aims to make India a leading producer and exporter of Green Hydrogen by 2030.
2. The Mission targets production of at least 5 MMT of Green Hydrogen per annum by 2030.
3. The Mission is expected to attract investment of over ₹8 lakh crore by 2030.
PYQ
Which of the following correctly distinguishes 'Green Hydrogen' from 'Blue Hydrogen'?
1. Green Hydrogen is produced by electrolysis of water using renewable electricity, while Blue Hydrogen is produced from natural gas with carbon capture and storage (CCS).
2. Green Hydrogen has zero lifecycle carbon emissions, while Blue Hydrogen has near-zero emissions due to CCS.
3. Blue Hydrogen is cheaper to produce than Green Hydrogen currently.
Select the correct answer:
PYQ
The Strategic Interventions for Green Hydrogen Transition (SIGHT) programme under India's National Green Hydrogen Mission provides incentives for which of the following?
1. Domestic manufacturing of electrolysers
2. Production of Green Hydrogen and Green Ammonia
3. Import of fuel cell vehicles
Select the correct answer:
PYQ
With reference to the Hydrogen colour coding system, match the following correctly:
Hydrogen Type — Production Method
A. Turquoise Hydrogen — 1. Electrolysis using nuclear energy
B. Pink Hydrogen — 2. Methane pyrolysis (producing solid carbon)
C. Brown Hydrogen — 3. Gasification of lignite coal without CCS
D. White Hydrogen — 4. Naturally occurring geological hydrogen
Choose the correct matching: