What is Green Hydrogen?

Scientists consistently repeat the same warning: “Fossil fuels should be abandoned to mitigate the impacts of climate change!” The clock is ticking. Increasing greenhouse gas emissions also stir up global temperatures.

So, are there remedies and alternatives?

Yes. The remedy is renewable energy sources and low carbon alternative fuels such as green hydrogen produced using these sources.

Let us now analyze the answer to the question of what green hydrogen is.

For more information on climate change, you can check our article here.

What is Hydrogen?

Hydrogen is the lightest and most commonly found element in the universe. Hydrogen plays a significant role in energy production of the stars and in the structure of various compounds such as water. In addition, it is one of the developing tools today that helps tackling climate change as a clean fuel alternative. Hydrogen can have different names depending on its production method. The most common kinds are green, blue, and gray hydrogen.

Three Colors / Three Categories in Hydrogen Production?

As we mentioned above, hydrogen is the most abundant element in the world. It comes to the fore as a light and storable energy carrier. Another property of hydrogen is its invisibility. So, why is it expressed with three color ranges; gray, blue and green? Let us look into it in more detail.

Hydrogen only emerges as a result of decomposition from other elements and wastewater is released during this decomposition process. The color of the released water determines the names given to hydrogen processing operation;

Gray Hydrogen: This is hydrogen obtained from fossil fuels and the most common one is the one obtained from natural gas. We can say that gray hydrogen is the cheapest one to produce currently. Therefore, gray hydrogen is not an alternative to mitigate the impacts of climate change. On the contrary, it maintains an energy system based on fossil fuels and carbon emissions.

Blue Hydrogen: Blue hydrogen is also obtained from fossil fuels; however, it is a pollutant to a lesser degree compared to gray hydrogen since it is obtained through techniques that can capture and store the generated CO₂ emissions. Nevertheless, blue hydrogen achieves to reduce emissions only during the production process instead of completely eliminating emissions. Therefore, blue hydrogen fuels are not a remedy for the climate problem of our planet.

Green Hydrogen: Known as renewable hydrogen, green hydrogen production enables us to obtain clean fuel from renewable energy sources. “Green hydrogen” is already seen as a big hope to replace fossil fuels in the sectors which present challenges for decarbonization. Both governments and private sector acknowledge that hydrogen is an important actor in a completely sustainable energy transformation.

Each one of the production methods differ in terms of the environmental impact and the cost of hydrogen.

What are the Kinds of Fuel Used for Hydrogen Output?

According to the International Energy Agency ( IEA), hydrogen production is responsible for greenhouse gas emissions equivalent to nearly 830 million tons of carbon dioxide per year. According to IEA, the global hydrogen demand in 2020 was 90 million tons, however fossil fuels were used to produce the majority of this amount. According to the estimations of IEA, nearly 99% of hydrogen across the world is obtained from natural gas, coal or petrol which cause high amounts of greenhouse gas emissions.

Therefore, hydrogen produced via these processes is neither clean nor sustainable!

Chemical reactions consisting of different techniques and processes such as molecular conversion are used to obtain hydrogen. Today, the commonly used method for hydrogen output is the conventional steam reforming method which includes capturing and decomposing carbon dioxide inside natural gas. This captured carbon dioxide gas is stored in ocean bottoms, petrol, and natural gas beds.

Hydrogen can also be obtained by water steaming produced by coal or biomass incineration and by gasification from pure oxygen. Coal or biomass is incinerated in a reactor at high temperatures. During the burning, gases are released which release hydrogen on the one hand and carbon monoxide on the other. The biggest problem with hydrogen fuels is the most common one being the use of “gray hydrogen” and “blue hydrogen” being positioned as a lesser bad option compared to the previous.

Therefore, when hydrogen is in question, the only applicable, clean and sustainable option at this point is “green hydrogen.”

How is Green Hydrogen Produced?

The most sustainable and common method to obtain green hydrogen is water electrolysis using renewable energy. This method consists of using a continuous electricity current that passes through the electrodes in the water, thus decomposing water (H₂O) into oxygen (O2) and hydrogen (H2) gases. Therefore, no carbon emission happens, and our world does not get polluted.

Pioneering Countries in Green Hydrogen Production

If the global economy is to be decarbonized, hydrogen will play a critical role. In the report of Intergovernmental Panel on Climate Change (IPCC), which was signed by all 193 governments in the UN, “green hydrogen” usage is one of the most important subjects.

In the race of producing green hydrogen, a few countries are ready to lead in this field.

​A report prepared by the International Renewable Energy Agency (IRENA) at the beginning of 2024 analyzed the political and economic changes that occurred for the energy sector to focus on this new, clean fuel. In short, the countries which prepare to pioneer in the development of political initiatives, technologies, and facilities to popularize “green hydrogen” are given below:

1. China: The largest hydrogen consumer and producer in the world, however the majority of the hydrogen in the country is ‘gray’ hydrogen, i.e., produced using fossil fuels. But China has been changing its attitude since 2019. The Asian giant China has over 30 ongoing green hydrogen projects. In other words, they are investing in hydrogen produced from renewable energy sources. As it is included in the next five-year plan of the country, China will start to use green hydrogen in six industries, 16 provinces and municipalities.

2. European Union: European Union (EU) has explicitly declared that green hydrogen is one of the ley technologies to achieve the goals of European Green Deal. To achieve this, European Clean Hydrogen Alliance was established with the purpose of decarbonization of European economy in order to promote investments and to propagate green hydrogen projects at a large scale. Spain is leading this race in Europe. Spanish Government’s Road Map includes national targets to put green hydrogen into action before 2030, including 4 GW electrolyzer, and envisages a reduction in greenhouse gas emissions equivalent to 4.6 million tons of CO2.

3. India: While presenting National Hydrogen Mission in 2021, the prime minister Narendra Modi stated that green hydrogen can help India to achieve energy independence in 2047. The first stage of “India Using Green Hydrogen” project focuses on promoting clean energy supply to meet the expected demand for this clean fuel.

4. Japan: According to IRENA report, Japan has made history as the first country to create a national hydrogen strategy in 2017 as part of its goal of using this fuel in all sectors. In 2020, the investment made in technologies associated with hydrogen and fuel batteries reached 670 million USD. This figure increases incrementally in Japan every year. Although Japan does not have an adequate amount of renewable energy sources such as wind or sun to use renewable energy to produce green hydrogen by itself, attention is drawn to the country’s long-term supply agreements to import hydrogen. From this perspective, Japan is among the countries that takes decisive steps to advance in this field.

5. South Korea: First stage of the green hydrogen project of South Korea consists of an ambitious target such as introducing 200,000 electric vehicles into the market by 2025. And the ambition of South Korea is proven by the increase in the usage of electric vehicles by 20 times compared to 2020. In addition, South Korea has approved Hydrogen Economic Development and Security Control Law in 2021 as a first in the world which aims to promote hydrogen powered vehicles, charging stations and fuel batteries.

In summary, green hydrogen development and production plans are proliferating across the globe. This reality gets us closer to a future in which this fuel can finally assume the role needed to decarbonize the planet.

The Role of Green Hydrogen in Energy Transformation

To sum up, green hydrogen, also known as renewable hydrogen, is essentially produced through water electrolysis using electricity currents. If the electricity used in this process is produced from renewable energy sources such as wind or solar energy, the final product is categorized as green hydrogen. This process does not result with greenhouse gas or pollutant waste. Actually, the only waste it generates is wastewater. Finally, less than 1% of the hydrogen produced across the world is green hydrogen. However, it seems that this clean fuel will play a key role in ensuring the future of our planet in the near future.