Hydrogen Economy: Green Hydrogen Mission and Applications
TOPIC CLASSIFICATION
Subject: Science & Technology / Environment Sub-area: Energy / Climate Change Prelim PYQ Trend: Low to Moderate (gaining frequency) Mains Relevance: GS-3 (Energy, Environment, Economy)
EXAMINER REASONING
Green hydrogen is a high-importance topic given India's climate commitments (Net Zero 2070) and energy transition. The examiner tests: (a) technical differentiation — grey, blue, green hydrogen; electrolysis methods (alkaline, PEM, solid oxide); (b) India's National Green Hydrogen Mission — targets, financial outlay, hubs; (c) applications — fertiliser (green ammonia), steel (green DRI), refining, heavy transport, power generation; (d) challenges — cost of electrolysers, water availability, storage, transport infrastructure. Expect questions linking hydrogen to energy security, climate goals, and industrial competitiveness.
Core Concept
What is Green Hydrogen? Hydrogen produced by splitting water into hydrogen and oxygen using renewable electricity (electrolysis), resulting in zero carbon emissions.
Types of Hydrogen (Colour Classification):
| Type | Source | CO₂ Emissions |
|---|---|---|
| Grey | Natural gas (steam methane reforming — SMR) | High (~10 kg CO₂/kg H₂) |
| Blue | Natural gas + Carbon Capture (CCUS) | Low (50-60% captured) |
| Green | Renewable electricity + Electrolysis | Zero (production) |
| Turquoise | Methane pyrolysis | Solid carbon byproduct |
| Pink |