Green hydrogen or renewable hydrogen is an alternative fuel produced through electrolysis, hence separating it from water. In this process, renewable sources such as solar or wind energy, among others, are used.
Green hydrogen combined with oxygen liberates chemical energy, and water vapor alone is produced as a result of combustion. It doesn’t generate greenhouse gases.
Below are two methods to produce green hydrogen as an alternative fuel.
With water vapor from natural gas
This process combines methane with water vapor to produce CO2 and hydrogen through an endothermic chemical reaction (Javier Brey, ABC, 2020).
It is important to stress that this traditional method is the most used in the production of industrial hydrogen. For this method to produce zero emissions, it is necessary to use biogas.
It dissociates water molecules into hydrogen and oxygen.
Due to the apparently unstoppable problem of climate change, green hydrogen is recovering the relevance it had decades ago when NASA used it in the first combustion motors for spaceships. Presently, green hydrogen is seen as a potential alternative for the reduction of CO2 emissions.
People have known about green hydrogen for a long time. Nowadays, it is considered useful again because it improves electrolysis and reduces the price of electric renewable energy, which we have been using in the last years (Javier Brey, ABC, 2020).
According to Hydrogen. The Energetic Vector of a Decarbonized Economy, due to geographic and climatic characteristics, Spainhas a green hydrogen production potential of 1.750 TWh/year. This is equivalent to 11 times the present consumption of natural gas (160TWh/year), excluding natural gas used for generation.
This places Spain as the country with the highest potential to produce hydrogen in Europe (Naturgy Foundation, 2020).
Differences between green hydrogen and conventional energy sources
The majority of conventional energy sources come from hydrocarbon and carbon mines. Taking this into account, green hydrogen is a renewable energy. It is also a clean energy leaving no dangerous waste.
Additionally, it is found in nature and it can be produced in faraway places with no electric infrastructure.
When used as fuel, it only produces water vapor, producing three times more energy than gasoline.
It is important to remember that green hydrogen is always produced. Therefore, it is not really fuel but an energetic vector.
Because of the process involved in its production, green hydrogen is an expensive technology when compared to traditional energy. Contrary to carbon, since it is not found isolated in nature, it is difficult to produce.
Lastly, green hydrogen has a low energy density. For example, compared to methane, one liter of methane produces one third of the energy produced by a liter of hydrogen.
Main applications of green hydrogen
1. As a fuel, it is used in long distance, massive and marine transportation, in spaceships and in mining trucks.
2. It is useful in electricity generation.
– Mitigation of pollutants produced by trucks circulating in open sky.
– Reduction of underground mining gases thus reducing ventilation costs.
4. In agriculture, it is used for the preparation of fertilizers based on green hydrogen. These fertilizers reduce CO2 contamination.
5. Production of synthetic fuel combined with CO2.
6. Storage of renewable energy, clean energy.
7. Production of ammonia.
8. In the oil industry:
– In oil refineries to produce conventional fuel.
– Displacement of natural gas for final consumption.
9. As raw material for industrial processes.
Challenges and opportunities
1. High transportation and storage costs.
2. Presently, high production costs make it less competitive compared to other energy sources (National Geographic, 2020) such as offshore wind farm.
3. To use this hydrogen, an energy transition is needed.
4. In the near future, European countries should consider importing this fuel because the continent has a low availability of resources and limited space for production.
5. Close to 95% of the hydrogen produced nowadays comes from nonrenewable sources.
6. Slow development of required infrastructure.
7. Present legislation limits the development of industrial activity around green hydrogen (Natura Foundation, 2019).
1. It is an option as a replacement for fossil fuels in the transportation sector.
2.It has different uses: methanol, synthetic liquid fuel, ammonia and synthetic methane (CH4).
3. This type of hydrogen can be used as drinking water for astronauts.
4. It is a fuel with zero or minimum CO2 emissions.
5. Compared to fossil fuel, it requires less energy to work.
6. Hydrogen is an infinite energy source.
7. It is safer for health and for the environment than nuclear energy or gasoline.
8. In 2050, renewable hydrogenwill be a crucial element to reach the goals of the European Green Deal.
9. For 2025, EGHAC has promised an investment of 100,000 million Euros to accelerate the production of green hydrogen in the continent. The production will be at a gigawatt scale and will be used for the implementation of industrial projects.
10. It will promote the fast development of technologies in different industries such as steel, cement and transportation.
11. It will be an opportunity to take advantage of the experience gained with the growth in the trade of natural gas to promote the first transoceanic routes for the transportation of hydrogen (Natura Foundation, 2019).
What’s the benefit of green hydrogen for the environment?
Since it produces emissions of hydrogen instead of CO2 and other contaminating gases, it is a way to reduce the emission of greenhouse gases.
Moreover, green hydrogen, being a renewable energy, is clean and does not produce harmful waste which is expensive and difficult to manage.
Green hydrogen is an inexhaustible energy and it is naturally regenerated. With this energy, natural resources are not affected by over exploitation as is the case with hydrocarbons.
Some projects using green hydrogen
Presently, Europe is building the biggest green hydrogen plant for industrial production of ammonia. Iberdrola in Puertollano, Ciudad Real, Castilla-La Mancha is in charge of this mega project.
Puertollano is composed of a solar 100 MW photovoltaic plant, a lithium battery system with a storage capacity of 20 MWh and one of the biggest hydrogen electrolysis production systems in the world (20 MW) (Iberdrola, 2020). It will start functioning in 2021, with 100% renewable sources, and it will prevent 39,000 tCO2/year emissions.
With the technology change, Fertiberia will produce green fertilizers. It is important to remember that Fertiberia’s production capacity is higher than 200,000 t/year, and it is one of the most efficient factories in the EU.
Presently, green hydrogen has become the first alternative to zero or minimal CO2 emission fuel, given that it is found abundantly in nature and has many applications.
On the other hand, it is good to remember that the high costs of production make it less competitive when compared to other energy sources.
It is also important to remember that the sources of green hydrogen are 100% renewable.
Among the big opportunities to produce itone can find the possibility of an alliance with the gas sector. This will allow for the transportation of hydrogen through the gas pipelines and will sensitize surrounding plants, chemical industries and refineries to its use. The last step in this process will be to manage the production of green hydrogen from 100% renewable sources.
Bibliography:Fernández P. (2020). How to Obtain Green Hydrogen. ABC Motor. Retrieved from: link
Fundación Naturgy. (2020). Hydrogen. Energetic Vector of a Decarbonized Economy. Retrieved from: link
Renewable Gas. (2019). The Time of Green Hydrogen. Retrieved from: link
Iberdrola. (2020). Iberdrola will Build the Biggest Hydrogen Plant for Industrial Use in Europe. Retrieved from: link
National Geographic. (2020). Advantages and Disadvantages of Hydrogen as an Alternative Fuel. Retrieved from: link