Hydrogen, the simplest and most abundant element in the universe, has the potential to be the fuel of the future. It’s an energy carrier that can store and deliver energy in a usable form. In its pure form, hydrogen is a colourless, odourless, and non-toxic gas. It’s high in energy, yet an engine that burns pure hydrogen produces almost no pollution, making it a desirable source of power.
Hydrogen Energy
Hydrogen energy refers to the use of hydrogen gas (H₂) as a fuel or energy carrier. When used in fuel cells or combusted, hydrogen can produce energy with little to no harmful emissions. It can be generated from various sources, including water and hydrocarbons, and can power vehicles, generate electricity, and provide heat for industrial processes.
As the world grapples with the challenges of climate change, the shift to clean and sustainable energy sources has become a critical priority. Traditional fossil fuels—coal, oil, and natural gas—are the primary drivers of greenhouse gas emissions, contributing to global warming, extreme weather events, and environmental degradation. Clean energy technologies, such as hydrogen, offer potential pathways to reduce carbon emissions, enhance energy security, and support economic development.
READ MORE: The Future of Carbon Capture: Can It Really Reverse Climate Change
Chemical Properties of Hydrogen
Hydrogen is the simplest and lightest element in the periodic table, with the chemical symbol H and an atomic number of 1. It typically exists as a diatomic molecule (H₂) and is colorless, odorless, non-toxic, and highly flammable. Its high energy content per unit mass (approximately 120 megajoules per kilogram) makes it a powerful energy carrier.
Some key properties include:
Atomic weight: 1.008
Boiling point: -252.87°C
Highly reactive: Especially with oxygen, forming water (H₂O)
Abundant: Though rarely found in its pure form on Earth, it is present in water, organic compounds, and hydrocarbons.
These characteristics make hydrogen ideal for energy storage and high-temperature industrial processes, but also require careful handling and storage.
Methods of Hydrogen Production
Hydrogen does not exist freely in nature and must be extracted from hydrogen-containing compounds. The production method greatly influences environmental impact and costs. Hydrogen is commonly categorized by “color codes” that indicate the method and sustainability of production:
1. Grey Hydrogen
Source: Natural gas (methane) through Steam Methane Reforming (SMR)
Process: Methane reacts with steam to produce hydrogen and carbon dioxide
Emissions: High CO₂ emissions; the most common and cheapest form today
Sustainability: Non-renewable and polluting
2. Blue Hydrogen
Source: Same as grey hydrogen, but paired with Carbon Capture and Storage (CCS)
Process: Similar to SMR, but 50–90% of CO₂ emissions are captured and stored underground
Emissions: Lower than grey hydrogen
Sustainability: Transitional technology—less polluting but still reliant on fossil fuels
3. Green Hydrogen
Source: Electrolysis of water powered by renewable electricity (solar, wind, hydro)
Process: Splits water into hydrogen and oxygen using an electric current
Emissions: Zero during production if powered by renewables
Sustainability: Most environmentally friendly, but currently expensive
4. Turquoise Hydrogen
Source: Methane Pyrolysis
Process: Methane is heated in the absence of oxygen, producing hydrogen and solid carbon
Emissions: No CO₂ if the carbon is captured and stored or used
Sustainability: Emerging technology with potential for low emissions
Basics of Hydrogen Fuel Cells and Combustion
| Hydrogen Type | Production Method | Energy Source | CO2 Emissions | Environmental Impact | Climate Suitability |
| Grey Hydrogen | Steam Methane Reforming (SMR) | Natural gas (fossil fuel) | High (~9-12 kg CO₂ per kg H₂) | Significant GHG emissions contribute to global warming | Unsustainable |
| Blue Hydrogen | SMR + Carbon Capture and Storage (CCS) | Natural gas + CCS | Moderate (up to 90% CO₂ captured) | Lower emissions but still fossil-based; CCS has leakage risks | Transitional |
| Green Hydrogen | Electrolysis of water | 100% renewable electricity (solar, wind, hydro) | Zero (if powered by renewables) | Very low environmental impact; minimal land and water use if managed properly | Climate-friendly |
| Turquoise Hydrogen | Methane Pyrolysis | Natural gas with renewable/electric heat | Low (solid carbon produced instead of CO₂) | Emerging; depends on a clean heat source and carbon storage | Promising but unproven |
Hydrogen can release energy in two main ways:
1. Hydrogen Fuel Cells
How it works: A hydrogen fuel cell generates electricity through an electrochemical reaction between hydrogen and oxygen. The only byproducts are electricity, water, and heat.
Applications: Used in vehicles (like Toyota Mirai), backup power systems, and distributed energy generation
Advantages: Clean, efficient, and quiet
2. Hydrogen Combustion
How it works: Hydrogen can also be burned in engines or turbines like traditional fuels. It combusts with oxygen to produce water vapor.
Applications: Industrial heat, power generation, modified internal combustion engines
Challenges: Requires special engine designs to prevent NOₓ emissions and ensure safety
The Pros of Hydrogen Energy – Advantages
1. Clean Energy
One of the main advantages of hydrogen energy is that it can be a clean energy source. Unlike fossil fuels, which emit pollutants and greenhouse gases when burned, hydrogen only produces water vapour when used as a fuel. If we use renewable energy to produce hydrogen, there are no direct emissions. Hydrogen made with renewable energy sources is known as green hydrogen. Hydrogen made from fossil fuels, such as natural gas, is called grey hydrogen.
2. Storing Renewable Energy
Hydrogen offers a viable way to store renewable energy for extended periods. Intermittency and storage are both significant issues facing renewables. Currently, batteries are less energy efficient and less cost-effective than the global energy transition needs.
Utilising hydrogen as a storage medium will promote and facilitate the use of renewable energy and help fight global warming. Through these pathways, sustainable hydrogen energy or green hydrogen can significantly reduce carbon dioxide emissions and help mitigate climate change. According to the International Energy Agency, hydrogen has the potential to reduce greenhouse gas emissions by 60 Gt between 2021 and 2050.
3. Hydrogen Is Versatile
One of the pros of hydrogen energy is its versatility. It can generate electricity, heat buildings, power vehicles, and even produce industrial chemicals. This makes hydrogen energy a potential solution for a wide range of applications, such as hydrogen-powered vehicles. This variability is highly beneficial for hard-to-decarbonise industries that lack many viable renewable energy alternatives.
One of the applications growing in popularity is hydrogen fuel cells. Hydrogen fuel cell technology is a potential game-changer for the transportation industry, particularly for vehicles unsuitable for plug-in battery solutions. Both planes and heavy-duty trucks fit this category because they depend on weight. Hydrogen is a light alternative to heavy batteries.
4. Renewable Energy
Hydrogen energy is also a renewable energy source when produced using electrolysis. Electrolysis produces hydrogen by splitting water into oxygen and hydrogen gas. This hydrogen production process can be carried out continuously as long as water and energy are available. When electrolysis uses renewable energy, the direct carbon footprint is near zero.
5. Zero Emissions at Point of Use
When hydrogen is used in fuel cells, the only byproduct is water vapor, meaning no carbon dioxide (CO₂), nitrogen oxides (NOₓ), or particulate matter are released into the air. This is a major advantage over fossil fuels and even over some biofuels, especially for transportation and urban applications where air quality is a concern. This feature makes hydrogen a zero-emission solution for end users, contributing directly to climate mitigation and cleaner air.
6. Reduces Dependence on Fossil Fuels and Enhances Energy Security
Hydrogen can be produced domestically from water and renewable electricity, helping countries reduce their reliance on imported oil and natural gas. This increases energy independence and resilience, especially during geopolitical disruptions (e.g., oil shocks, war-driven fuel shortages). Additionally, hydrogen offers diverse applications—transport, industry, and power—making it a strategic component of a self-reliant clean energy future.
7. Supports Carbon-Neutral Goals and Green Economies
As governments adopt net-zero carbon targets, hydrogen can become a core part of national and international climate strategies. Investments in hydrogen technology can stimulate green innovation, create jobs, and support a just transition away from fossil fuels. Green hydrogen in particular helps align with the Paris Agreement targets by reducing life-cycle emissions and enabling carbon-neutral energy systems.
Cons of Hydrogen Energy – Disadvantages
1. Production and Storage Costs
However, hydrogen energy has several significant drawbacks. One of the biggest disadvantages of hydrogen energy is the cost of producing and storing hydrogen. Currently, electrolysis is relatively expensive and energy-intensive. Additionally, hydrogen is a gas at room temperature and must be stored in high-pressure or cryogenic tanks. The infrastructure required to complete this process is cost-prohibitive.
2. Lack of Infrastructure
One downside of hydrogen energy is the lack of infrastructure. While hydrogen vehicles and power plants exist, there aren’t enough to support widespread hydrogen use as a fuel source. According to the U.S. Department of Energy, there were only 48 hydrogen fueling stations in the United States by mid-2021.
- Pipelines that can handle high-pressure hydrogen
- Refueling stations for vehicles
- Storage tanks that can withstand cryogenic or high-pressure conditions
3. Energy Density
Finally, hydrogen has a low volumetric energy density. Uncompressed, the amount of energy in 1 L of hydrogen is about one-fourth of the amount in gasoline. However, when compressed into a liquid, the energy density is three times that of gasoline. As previously discussed, compressing hydrogen is an expensive process that adds to the financial roadblock to hydrogen adoption.
4. Carbon Intensity of Grey and Blue Hydrogen
Most hydrogen today is produced via grey hydrogen, which emits significant CO₂—roughly 9 to 12 kg of CO₂ per kg of H₂. Even blue hydrogen, which uses CCS, may capture only 60–90% of its emissions, and some studies argue that methane leaks during natural gas extraction can undermine its climate benefits. Thus, unless hydrogen is green, it can still contribute to climate change, contrary to its clean-energy image.
5. High Costs and Scalability Issues of Green Hydrogen
- Green hydrogen requires:
- Expensive electrolyzers
- Large amounts of renewable electricity
- Complex infrastructure for distribution
As of now, it costs between $3 and $7 per kg, significantly more than grey hydrogen (~$1–$2/kg). Until prices fall due to technological advances, economies of scale, and supportive policies, green hydrogen will remain economically uncompetitive, slowing down widespread adoption.
Case Studies
1. Germany’s Hydrogen Trains – Alstom Coradia iLint
Overview: Germany launched the world’s first hydrogen-powered passenger trains in 2022, replacing diesel engines on non-electrified tracks.
Technology: These trains use hydrogen fuel cells to generate electricity, with water vapor as the only emission.
Impact: They reduce CO₂ emissions by up to 55,000 tons annually and offer a quiet, clean transport solution for rural routes.
Significance: This is a major step toward green public transportation and shows hydrogen’s potential to replace fossil fuels in rail networks.
2. Japan’s Hydrogen Society Strategy
Overview: Japan is a global pioneer in hydrogen investment, aiming to become the world’s first full-fledged “Hydrogen Society.”
Projects:
The Fukushima Hydrogen Energy Research Field (FH2R) is one of the world’s largest green hydrogen facilities.
Toyota’s Mirai hydrogen fuel cell vehicle is mass-produced and widely adopted in Japan.
Impact: Hydrogen is central to Japan’s 12 decarbonization roadmaps and its energy security strategy after the Fukushima nuclear disaster.
Significance: Japan’s long-term hydrogen vision demonstrates hydrogen’s viability beyond the experimental phase.
- Policy Frameworks Supporting Hydrogen
- The Paris Agreement and national climate targets (NDCs).
- European Green Deal and EU Hydrogen Strategy.
- India’s Green Hydrogen Mission.
- Role of the International Energy Agency (IEA) and Hydrogen Council.
Global Policy Frameworks and Investments
European Union
The EU Hydrogen Strategy (2020) aims to install at least 40 GW of electrolyzer capacity by 2030. Through the European Clean Hydrogen Alliance, the EU supports infrastructure, standards, and public-private partnerships.
China
China is investing heavily in hydrogen infrastructure and fuel cell vehicles, aiming for 1 million FCVs by 2030. It initially emphasizes grey and blue hydrogen, gradually incorporating green hydrogen.
Middle East and North Africa (MENA)
Countries like Saudi Arabia and Morocco are investing in large-scale green hydrogen production for export. NEOM, a \$500 billion megacity project in Saudi Arabia, includes one of the world’s largest planned green hydrogen plants.
India
India launched its National Green Hydrogen Mission in 2023, aiming to produce 5 million tons of green hydrogen annually by 2030. The initiative emphasizes domestic electrolytic manufacturing and the integration of renewable energy.
Future Outlook and Challenges
The Hydrogen Council estimates that hydrogen could meet 18% of the world’s energy demand and reduce CO₂ emissions by 6 Gt annually by 2050. However, achieving this vision requires:
- Cost reductions through technological innovation and scale.
- Global coordination on regulations and infrastructure.
- Public-private partnerships to fund and de-risk investments.
- Public awareness and workforce training.
Advanced research is also exploring hydrogen carriers like ammonia and liquid organic hydrogen carriers (LOHCs) to simplify storage and transport.
FAQs About Hydrogen Energy
Is hydrogen really the fuel of the future?
Hydrogen is considered a promising future fuel because it can produce energy with zero emissions at the point of use, especially when used in fuel cells. It is versatile, renewable when produced using green methods, and useful for hard-to-decarbonize sectors like heavy transport and industry. However, high production costs, limited infrastructure, and storage challenges mean that hydrogen will complement not replace other clean energy sources.
What is the difference between grey, blue, green, and turquoise hydrogen?
Grey hydrogen is made from natural gas and releases high CO₂ emissions.
Blue hydrogen is the same process but uses carbon capture to reduce emissions.
Green hydrogen is produced through electrolysis using renewable energy, creating zero emissions.
Turquoise hydrogen uses methane pyrolysis to produce hydrogen and solid carbon, offering low-emission potential if powered sustainably.
How do hydrogen fuel cells work?
Hydrogen fuel cells convert chemical energy into electricity through a reaction between hydrogen and oxygen. This electrochemical process produces electricity, heat, and water vapor as the only byproduct. Fuel cells are highly efficient, quiet, and ideal for vehicles, backup power, and clean industrial applications.
What are the main advantages of hydrogen energy?
Hydrogen offers several benefits including zero emissions at point of use, high energy content per unit mass, the ability to store renewable energy long-term, and wide applicability across transport, power generation, and industry. It also supports energy security by reducing reliance on imported fossil fuels and contributes to global net-zero goals when produced sustainably.
What challenges are preventing widespread adoption of hydrogen energy?
The biggest obstacles include high production and storage costs, limited fueling infrastructure, low volumetric energy density, and dependence on fossil fuels for grey and blue hydrogen. Green hydrogen remains expensive due to costly electrolyzers and the need for large amounts of renewable electricity. Scaling up global hydrogen systems requires investment, regulations, and advanced technologies.
ALSO READ: Should Governments Ban Fossil Fuels? Pros and Cons Explained
Conclusion
Hydrogen holds immense promise as part of a diversified, low-carbon energy portfolio. Its flexibility, environmental benefits, and its application in hard-to-decarbonize sectors make it an attractive solution. However, substantial technological, economic, and infrastructural barriers must be overcome.
Rather than being a universal replacement for fossil fuels, hydrogen is best viewed as a complementary solution—one that works in tandem with electrification and other renewable technologies. Through coordinated global policy, investments, and innovation, hydrogen can play a key role in shaping a sustainable and resilient energy future.
References
- https://www.weforum.org/stories/2023/12/why-hydrogen-is-the-fuel-of-the-sustainable-future/
- https://www.sciencedirect.com/science/article/abs/pii/S0360319923039988
- https://energytracker.asia/pros-and-cons-of-hydrogen-energy/
- https://www.pirelli.com/global/en-ww/road/cars/hydrogen-as-a-fuel-the-pros-and-cons-53908/
- https://earth.org/pros-and-cons-of-hydrogen-energy/
- https://www.energy.gov/eere/fuelcells/hydrogen-and-fuel-cell-technologies-office
- https://www.iea.org/energy-system/low-emissions-fuels/hydrogen
- https://www.energy.gov/eere/fuelcells/increase-your-h2iq
- https://www.twi-global.com/technical-knowledge/faqs/what-are-the-pros-and-cons-of-hydrogen-fuel-cells
- https://www.nrel.gov/hydrogen
- “Hydrogen Energy: A Review” (Renewable and Sustainable Energy Reviews, 2020).
- “The Potential of Hydrogen Energy” (Energy Policy, 2019).
- “Hydrogen Fuel Cells: A Review” (Journal of Power Sources, 2020).
John is a professional blogger and passionate advocate for environmental sustainability. With years of experience exploring eco-friendly practices and green innovations, he shares insightful articles on Planet Flagship to inspire a sustainable future. John’s expertise lies in making complex environmental topics accessible and actionable, empowering readers to make meaningful changes for the planet.