Green hydrogen is hydrogen produced through the electrolysis of water using electricity generated from renewable energy sources (solar, wind, or hydropower). Unlike conventional hydrogen production, which relies on fossil fuels and emits significant greenhouse gases, the production of green hydrogen is virtually carbon-neutral, with water vapor as the only byproduct. It is considered a crucial “energy vector” for decarbonizing sectors that are difficult to electrify, such as heavy industry and long-distance transport.
Mechanisms of Production
The core of green hydrogen technology is the electrolyzer, which uses electricity to split water (H2O) into hydrogen (H2) and oxygen (O2). There are three primary types of electrolysis technologies:
- Alkaline Electrolysis: The most mature technology, utilizing an alkaline solution (potassium hydroxide) as the electrolyte. It is cost-effective and suitable for large-scale industrial applications.
- Proton Exchange Membrane (PEM) Electrolysis: Uses a solid polymer membrane as the electrolyte. It offers high efficiency and, crucially, can quickly adjust to the variable power supply typical of solar and wind energy.
- Solid Oxide Electrolysis (SOEC): Operates at high temperatures (700°C–1000°C), often utilizing waste heat from industrial processes to increase electrical efficiency.
Role in Governance and Economy
Green hydrogen is a cornerstone of India’s energy independence and net-zero strategy (Net-Zero 2070).
- Industrial Decarbonization: It acts as a clean feedstock for “hard-to-abate” sectors. For instance, in steelmaking, hydrogen replaces coking coal as a reducing agent in the Direct Reduced Iron (DRI) process.
- Fertilizer Industry: Used to produce green ammonia through the Haber-Bosch process, replacing natural gas-derived grey ammonia and reducing import dependency.
- Refining and Petrochemicals: Used for desulfurization of crude oil, enabling refineries to lower their Scope 1 emissions.
- Energy Storage: Hydrogen can store excess renewable energy for long durations, acting as a buffer for the national power grid when solar or wind generation is low.
- Transportation: Serves as a clean fuel for fuel cell electric vehicles (FCEVs), particularly heavy-duty trucks, buses, trains, and maritime shipping.
National Green Hydrogen Mission (NGHM)
Launched by the Government of India, the mission aims to position India as a global hub for the production, utilization, and export of green hydrogen.
| Target Parameter | 2030 Goal |
| Production Capacity | At least 5 Million Metric Tonnes (MMT) per annum |
| Renewable Energy Addition | Approximately 125 GW |
| Investment Attracted | Over ₹8 lakh crore |
| CO2 Emission Reduction | ~50 MMT annually |
- SIGHT Programme: Strategic Interventions for Green Hydrogen Transition (SIGHT) provides financial incentives for the domestic manufacturing of electrolyzers and the production of green hydrogen.
- Green Hydrogen Hubs: Development of regions (such as major port areas) capable of large-scale production, storage, and export of green hydrogen and its derivatives (e.g., green ammonia).
- Policy Support: Includes the Green Energy Open Access Rules to facilitate low-cost renewable power supply to green hydrogen producers.
Challenges to Scalability
- Cost Efficiency: Currently, green hydrogen is more expensive to produce than grey hydrogen (derived from natural gas). Achieving a target cost of USD1.5/kg by 2030 is essential for commercial viability.
- Storage and Transportation: Hydrogen has low volumetric energy density; it must be stored at extreme pressure (700 bar) or as a cryogenic liquid (-253°C), requiring specialized infrastructure.
- Resource Intensity: Large-scale production requires massive amounts of high-purity water and significant land for dedicated renewable energy installations.
- Technological Maturity: Scaling up domestic electrolyzer manufacturing capacity is critical to reducing reliance on global technology imports.
Key Distinctions in Hydrogen Types
- Grey Hydrogen: Produced from natural gas (methane) via Steam Methane Reforming (SMR); produces significant CO2.
- Blue Hydrogen: Produced like grey hydrogen but incorporates Carbon Capture and Storage (CCS) to mitigate emissions.
- Green Hydrogen: Produced from water via electrolysis using renewable energy; zero carbon emissions.