Hydrogen Generation as a Fuel Source
Science & Technology › Biotechnology – Applications · Topic 11.11
Hydrogen is a clean fuel that releases only water when it burns or reacts in a fuel cell, but it does not occur free in nature and must be made from other substances. It is made by steam methane reforming of natural gas, by gasification of coal, by electrolysis of water, and by biological routes. Hydrogen is described by colour: grey from fossil fuels with emissions, blue when the carbon dioxide is captured, and green when made by electrolysis using renewable electricity. India launched the National Green Hydrogen Mission in January 2023 with an outlay of Rs 19,744 crore and a target of 5 million tonnes of green hydrogen a year by 2030. Biohydrogen from microbes and algae is a research route that fits within biotechnology.
5 min read · UPSC Prelims · Science & Technology · Biotechnology – Applications
At a Glance
- Green route Electrolysis with renewable power
- Biological route Fermentation and algae
- Mission National Green Hydrogen Mission, 2023
- Outlay Rs 19,744 crore
- 2030 target 5 million tonnes a year
- Exam link UPSC Prelims, Science & Technology: Biotechnology – Applications
Where Does It Fit?
This topic follows biofuels. Hydrogen is another clean fuel, and the biological methods of making it connect the energy discussion to biotechnology. Previous topic: National Policy on Biofuels,…">Biofuels: Bioethanol, Biodiesel and Biogas from Biomass. Next topic: National Biotechnology Development Strategy 2015–2020.
How Is Hydrogen Made?
| Route | Details |
|---|---|
| Steam methane reforming | Natural gas reacts with steam to give hydrogen and carbon dioxide. The main commercial route, called grey hydrogen |
| Blue hydrogen | The same route with capture and storage of the carbon dioxide |
| Coal gasification | Coal is turned into a gas rich in hydrogen. Called brown or black hydrogen, with high emissions |
| Electrolysis of water | Electric current splits water into hydrogen and oxygen. With renewable power it gives green hydrogen |
| Pink and turquoise hydrogen | Pink uses nuclear power for electrolysis, and turquoise comes from methane pyrolysis with solid carbon as by product |
| Biological production | Microbes and algae make hydrogen by fermentation or photosynthesis |
| Natural hydrogen | Sometimes called white hydrogen, found in rocks, now being explored |
What Are the Biological Routes and Uses?
- Dark fermentation: bacteria such as Clostridium and Enterobacter break down sugars in the dark and release hydrogen
- Photofermentation: purple bacteria use light and organic acids to make hydrogen
- Biophotolysis: green algae and cyanobacteria split water with light and release hydrogen using the enzyme hydrogenase
- Microbial electrolysis cell: microbes help to produce hydrogen from waste water with a small electric input
- Fuel cells: devices that combine hydrogen and oxygen to make electricity, heat and water
- Transport: hydrogen buses, trucks, trains and ships are being tested
- Industry: green hydrogen can replace fossil hydrogen in fertiliser, refineries and steel
- Storage: hydrogen is stored as compressed gas, liquid, in metal hydrides or as ammonia
What Else Should You Remember?
- National Green Hydrogen Mission: approved in January 2023, it aims for 5 million tonnes of green hydrogen capacity a year by 2030, with about 125 gigawatts of related renewable energy capacity and cuts in fossil fuel imports
- SIGHT scheme: Strategic Interventions for Green Hydrogen Transition, which gives incentives for electrolyser manufacturing and green hydrogen production
- Green hydrogen hubs: the Government has identified coastal and industrial regions as hubs, such as Kandla, Paradip and Tuticorin
- Pilot projects: pilots on green hydrogen for buses, steel and refineries are underway, and India has a Hydrogen Valley Innovation Cluster
- Energy density: hydrogen holds about three times the energy of petrol per kilogram, but little per litre as a gas
- Challenges: high cost of green hydrogen, low efficiency, storage and transport difficulty, and safety as hydrogen is flammable
- Water use: electrolysis needs fresh water, so water stress regions need sea water treatment or recycling
- Auctions: the Solar Energy Corporation of India has held auctions for green hydrogen and green ammonia with falling prices
- Global moves: the European Union, Japan, the United States and Australia have hydrogen strategies and trade plans
- Hydrogen colour code: the colours are a naming habit, not an official standard, so definitions should be checked
- Link: biological conversion of waste ties with Bio-Composting and Carbon Capture Techniques
- Link with biofuels: hydrogen and biofuels together serve sectors that are hard to electrify, as in Biofuels: Bioethanol, Biodiesel and Biogas from Biomass
- Green ammonia: hydrogen combined with nitrogen gives ammonia, which is easier to store and ship and can serve as fertiliser or fuel
- Hydrogen safety: hydrogen is light and flammable, so leaks must be detected, and storage and refuelling follow strict standards
Why Does It Matter for the Exam?
- Colours: grey, blue, green and others
- Methods: electrolysis and biological routes
- Mission facts: launch year, outlay and target
- Current affairs link: green hydrogen auctions and hubs
- Common errors: saying that all hydrogen is clean, or that green hydrogen comes from natural gas
As an analytical point, green hydrogen can cut emissions in industry and heavy transport, but cost is the main barrier. Scale, cheap renewable power and demand creation by the Government can bring prices down.
Why Is This Topic Important?
- Colours Production type
- Mission Targets and hubs
- Biology Biohydrogen
What Came Next?
The next topic covers the National Biotechnology Development Strategy. Next topic: National Biotechnology Development Strategy 2015–2020.
Key People and Terms
- Electrolyser Device to split water
- Fuel cell Hydrogen to electricity device
- Hydrogenase Hydrogen making enzyme
- Grey hydrogen From fossil gas
- Green ammonia Ammonia from green hydrogen
- Hub Cluster of production and use
Exam Corner
Points to Remember
- Green hydrogen mission: 2023, Rs 19,744 crore.
- Target: 5 million tonnes by 2030.
- Grey = fossil, green = renewable electrolysis.
- Enzyme: hydrogenase.
- Fuel cell emits water.
Do Not Confuse With
- Grey and blue hydrogen Without versus with carbon capture
- Green hydrogen and biohydrogen Electrolysis versus microbes
- Fuel cell and battery Makes power from fuel versus stores power
Memory Hook
Grey from gas, blue with capture, green from water and sun; microbes make it too.
Mains Angle
Questions ask about colours, the mission and challenges. These points help.
- Promise Clean fuel
- Challenges Cost and storage
- Policy Mission and hubs
A Question You May Face
An original practice question, not a past paper question.
“Discuss the potential of green hydrogen in India’s energy transition and the challenges that must be overcome.”
How to Answer
- Colours Grey to green.
- Mission Targets.
- Challenges Cost, storage.
- Way Scale, demand.
GS Relevance
Frequently Asked Questions
What is green hydrogen?
Green hydrogen is hydrogen made by splitting water into hydrogen and oxygen through electrolysis using electricity from renewable sources such as solar and wind. It produces no carbon dioxide during production and can replace fossil fuel based hydrogen in fertiliser, refining and steel, and can be used as a clean fuel.
What is the National Green Hydrogen Mission?
The National Green Hydrogen Mission was approved by the Union Cabinet in January 2023 with an outlay of Rs 19,744 crore. It aims to make India a hub for production, use and export of green hydrogen, with a target of 5 million tonnes a year by 2030, and it supports electrolyser making through the SIGHT scheme.
What is the difference between grey, blue and green hydrogen?
Grey hydrogen is made from natural gas by steam methane reforming and releases carbon dioxide. Blue hydrogen is made in the same way, but the carbon dioxide is captured and stored. Green hydrogen is made by electrolysis of water using renewable electricity and has the lowest emissions.
How can microbes produce hydrogen?
Some bacteria produce hydrogen by breaking down sugars in the dark, called dark fermentation, and purple bacteria do so using light, called photofermentation. Green algae and cyanobacteria can split water using light and release hydrogen with the enzyme hydrogenase. These biological routes are still mostly at research and pilot stage.
What is a fuel cell?
A fuel cell is a device that produces electricity directly from a chemical reaction between a fuel such as hydrogen and oxygen. The only products are electricity, heat and water. Fuel cells are used in test vehicles, back-up power and spacecraft, and they are more efficient than burning fuel in an engine.
PYQ Practice — Statement Analysis
1 Green hydrogen is produced by electrolysis of water using renewable electricity.
With no direct carbon emissions.
2 Grey hydrogen is produced by electrolysis powered by solar energy.
It comes from fossil fuels.
3 The National Green Hydrogen Mission was launched in 2023.
Outlay of Rs 19,744 crore.
4 The enzyme hydrogenase is involved in biological hydrogen production.
In algae and bacteria.
Past Mains Questions on This Topic
This topic comes under Biotechnology – Applications. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
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