Green Hydrogen, Meaning, Benefits, Production, Applications

Green hydrogen has emerged as a promising clean energy alternative that can play a significant role in decarbonising various sectors and mitigating climate change. Unlike blue hydrogen, which is produced from natural gas with carbon capture and storage, green hydrogen is a zero-emission fuel produced by electrolysing water using renewable energy sources like solar and wind.

India has set an ambitious target, through the National Green Hydrogen Mission, to reduce dependence on imported fossil fuels, create export opportunities, and support the country's goal of achieving net-zero emissions by 2070.

What is Green Hydrogen?

Green hydrogen is a colourless, odourless, tasteless, non-toxic, and highly combustible gaseous substance. It is the lightest, simplest, and most abundant element in the universe. The term "green" refers to the method of production, which involves the use of renewable energy sources like solar, wind, or hydel power for electrolysis. This process splits water into hydrogen and oxygen, without emitting greenhouse gases.

Green Hydrogen Advantages 

• Energy storage: Green hydrogen can be stored for long periods, making it suitable for grid stability by providing energy when renewable sources are intermittent.
• Monetary benefits: The oxygen produced as a by-product during electrolysis can be monetised for industrial and medical applications.
• Flexible energy carrier: Hydrogen can be used for various energy applications, including integrating renewable energy sources and transportation.
• Reduced emissions: Unlike grey hydrogen (produced from methane), green hydrogen production does not release greenhouse gases, and its byproduct is environmentally friendly water vapour.
• Global dominance: Several countries are experimenting with blending green hydrogen with natural gas for power generation, industrial applications, and residential use.

Green Hydrogen Disadvantages

• High cost: The production of green hydrogen through electrolysis using renewable energy sources is more expensive, making hydrogen costlier to obtain.
• High energy consumption: The production of green hydrogen requires more energy than other fuels.
• Safety concerns: Hydrogen is highly volatile and flammable, necessitating extensive safety measures to prevent leaks and explosions.

Green Hydrogen Production Methods

Green hydrogen production involves water electrolysis, where water (H2O) is split into hydrogen (H2) and oxygen (O2) using electricity from renewable sources. There are three main methods:

• Alkaline electrolysis: The most mature technology, uses an alkaline solution (KOH or NaOH) as the electrolyte. 
  • Despite its high efficiency and low cost, it requires expensive materials like nickel and platinum as electrodes.
• Proton exchange membrane electrolysis: An advanced method using a solid polymer membrane as the electrolyte. 
  • It offers higher efficiency and faster response times, but the high cost of the membrane and precious metal catalysts is a challenge.
• Solid oxide electrolysis: A high-temperature process (700°C to 1000°C) using a solid ceramic material as the electrolyte. 
  • It offers high efficiency and the potential for co-electrolysis (simultaneous conversion of water and CO2 into H2 and CO), but the high temperatures and need for specialised materials make it more complex and expensive.

Green Hydrogen Applications

Green hydrogen has a wide range of applications across various sectors, making it a versatile and valuable resource in the transition towards a sustainable and carbon-neutral future. The following are the key applications of green hydrogen:

• Transportation: Green hydrogen can fuel ‘Fuel Cell Electric Vehicles (FCEVs)’, offering longer driving ranges and faster refuelling times compared to battery electric vehicles (BEVs).
  • It can also power trains, ships, and aeroplanes, providing a cleaner alternative to traditional fossil fuels.
• Energy storage and grid integration: Green hydrogen can store excess renewable energy from intermittent sources like wind and solar.
  • It can be converted back into electricity when needed, helping to balance the energy grid and ensure energy security.
• Industrial applications: In the steel industry, green hydrogen can replace coal-based processes, significantly reducing emissions.
  • It can also replace fossil fuels in the production of ammonia, a key ingredient in fertilisers, and serve as a feedstock in various chemical processes.
• Residential and commercial applications: Green hydrogen can generate electricity for buildings through fuel cells and can be used for heating and cooking, replacing natural gas and other fossil fuels.
• Hydrogen blending: Green hydrogen can be blended with natural gas in existing pipelines and distribution networks, gradually integrating green hydrogen into the energy system and reducing the carbon footprint of natural gas consumption.
• Hydrogen trade: Countries with abundant renewable energy resources can produce green hydrogen for export, creating new economic opportunities and strengthening global energy security.

Green Hydrogen in India

India has set its sights on becoming energy-independent by 2047 and achieving Net Zero by 2070. To achieve this target, increasing renewable energy use across all economic spheres is central to India's Energy Transition. Green Hydrogen is considered a promising alternative for enabling this transition. 

• Financial funding: India has sanctioned a $2 billion incentive scheme to boost green hydrogen production. The initiative aims to improve the affordability of green hydrogen, positioning India as a significant exporter. Presently, the cost of green hydrogen in India is $4-5 per kg.
• Green Hydrogen Standard for India:
  • Definition: It defines green hydrogen as having a well-to-gate emission of not more than 2kg carbon dioxide equivalent per kg hydrogen, encompassing various production processes like electrolysis and biomass-based methods.
  • Scope: The standard covers water treatment, electrolysis, gas purification, drying, and compression of hydrogen, ensuring a comprehensive evaluation of the production process.
  • Nodal Authority: The Bureau of Energy Efficiency (BEE) under the Ministry of Power is responsible for accrediting agencies monitoring and certifying green hydrogen production projects.
• National Green Hydrogen Mission:
  • Initiated in January 2023, this mission targets an annual production of 5 million metric tonnes of green hydrogen by 2030, leveraging 125 gigawatts of renewable energy. 
  • It encompasses the SIGHT program, offering substantial financial backing to boost domestic electrolyser manufacturing and green hydrogen production, reinforcing India’s vision to emerge as a leading green hydrogen economy.

Green Hydrogen UPSC PYQs

Question 1: With reference to ‘fuel cells’ in which hydrogen-rich fuel and oxygen are used to generate electricity, consider the following statements : (UPSC Prelims 2015)

1. If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by-products.
2. Fuel cells can be used for powering buildings and not for small devices like laptop computers.
3. Fuel cells produce electricity in the form of Alternating Current (AC).

Which of the statements given above is/are correct?

1. 1 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

Answer: (a)

Green Hydrogen FAQs 

Q1. What is green hydrogen?

Ans. Green hydrogen is hydrogen produced through the electrolysis of water using renewable energy sources like solar, wind, or hydropower. It does not release greenhouse gases during production, making it an environmentally friendly fuel.

Q2. How is green hydrogen different from grey and blue hydrogen?

Ans. Grey hydrogen is produced from fossil fuels like natural gas or coal, releasing greenhouse gases. Blue hydrogen is also produced from fossil fuels but with carbon capture and storage technologies. Green hydrogen is the cleanest form as it uses renewable energy sources.

Q3. How is green hydrogen produced?

Ans. It is produced by electrolyzing water into hydrogen and oxygen using an electrolyzer powered by renewable electricity from solar, wind or hydro sources.

Q4. Why is India promoting green hydrogen?

Ans. India aims to transition to a low-carbon economy, increase renewable energy use, reduce fossil fuel imports, and become energy-independent by 2047. Green hydrogen aligns with these goals.

Q5. What are the applications of green hydrogen?

Ans. Transportation (fuel cells for vehicles), industrial processes, power generation, energy storage for grid balancing, fertilizer production, steel making, and more.