Figure 1: Mechanism used to produce green hydrogen through electrolysis
Source Credit: columbia.edu (LINK)
Did you know that 90 percent of all atoms in this universe is hydrogen? This might be exciting news to those who have read about President Biden’s plan on investing in clean energy. Hydrogen fuel has been a well-known resource for a long time, especially since it surprisingly only produces one byproduct when burnt—water. Unfortunately, hydrogen atoms do not exist by themselves, but rather are in combined forms just as they are in water and plants. Therefore, hydrogen should be decoupled from other atoms before turning into energy, but it is not as easy as it sounds. This stage of decoupling hydrogen atoms has actually been the major problem for researchers.
For years, the only practical way to turn hydrogen into usable energy was by using fossil fuels. Through a process called steam methane reforming, a catalyst helps methane and high temperature steam react, resulting in hydrogen as well as carbon monoxide. Then the carbon monoxide acts as a reactant, producing more hydrogen. However, hydrogen is not the only product in this chemical reaction. In both steps of steam methane reforming, an abnormal amount of carbon dioxide is produced, and due to high demand for hydrogen energy—mainly for chemical industries such as ammonia, fertilizer and oil refining manufacturers—830 million metric tons of carbon dioxide are produced every year. As per this negative side effect, the hydrogen energy created through this process is called ‘grey hydrogen.’ Despite the fact that it is an efficient energy source for many industries, the continuous production of grey hydrogen poses a great threat to the environment through air pollution. Therefore, scientists have been focusing heavily on searching for new hydrogen-producing methods that could be more eco-friendly.
One alternative is to capture and store CO2 from the steam methane reforming process; the resulting hydrogen is called ‘blue hydrogen’. However, there is a better mechanism. Instead of using fossil fuels to generate energy, as the aforementioned two methods do, we can use renewable energy to produce what we call ‘green hydrogen.’ Using solar or wind power, a machine can employ an electric current that can split water into hydrogen and oxygen, a process called electrolysis. If this could be converted into a real machine and if the majority of hydrogen fuel could be replaced with green hydrogen, it could possibly be introducing a new valuable resource that is efficient and nonpolluting.
So why are we not using green hydrogen yet? The reason behind the slow development of green hydrogen is due to the extreme amount of electricity needed for electrolysis. However, with recent technological advancements leading to cheap renewable energy and the growing availability, it seems as if green hydrogen could be produced in the near future, possibly in the next decade. Moreover, the electrolyzer, a cell in which electrolysis occurs, has become more efficient, and with the progress in the industry, it will soon be advanced enough so that the expense would no longer be a concern.
Recently, green hydrogen has been of interest to various sectors for its great potential as a top sustainable fuel. Some companies have started to directly employ electrolyzers to their renewable power projects, and many countries including Chile, China, and South Korea have revealed their plans on implementing hydrogen fuel for other technological growth and vehicles. Furthermore, the Department of Energy of the US and the European Union have invested 100 million and 430 billion dollars respectively to support research on hydrogen fuel cells with high expectations towards the future green hydrogen can possibly bring. As many people believe, the success of developing green hydrogen could introduce a new level of energy efficiency. Even the Paris Agreement goal of eliminating approximately 10 gigaton of CO2 per year does not seem to be a distant future with green hydrogen.
Q&A:
Jiwon: In your article, you mentioned that countries are investing in the implementation of hydrogen fuel for sectors of growth and current companies also working toward using green hydrogen. Apart from these such endeavors, what other efforts can be made for the rapid globalization of the use of green hydrogen?
It has been revealed that use of green hydrogen can greatly reduce the amount of carbon dioxide released in electricity production and transportation, so acknowledging its usefulness in these sectors, which are some of the top sources for worsening air pollution, may help globalize its use.
John: In what ways has the electrolyzer become more efficient?
They can now be integrated into projects directly so that they can help produce green hydrogen as cheaply as other hydrogen. For example, a project called Gigastack is planning to have 100 megawatts of electrolyzers for green hydrogen production.
Hannah: You mentioned that the process of creating green hydrogen consumes a lot of electricity, so is there a possibility that creating a lot of it ends up harming the environment?
That is partly the reason why the scientists have not implemented this hydrogen production in the past. However, with sufficient renewable energy and efficient electrolyzers, the researchers are optimistic about its potential. Also, even if it may not have enough resources or supporting technology, it will not harm the environment like grey hydrogen.
Eric: we go through the process of creating green hydrogen to make fuel, but that process requires energy in the first place; how much more energy is created through electrolysis, and does it justify going through an extra step?
Since green hydrogen production uses excess renewable energy in a way so that they are stored in hydrogen instead of batteries, researchers agree that the use of electricity is justified.
Wooseok: Are there any other disadvantages to this technology other than the requirement of excessive electricity?
The main disadvantage is cost; it is three times more expensive than natural gas and other hydrogen.
Josh: Are there any economic limitations in the installation of electrolyzers in various different areas? For example, is there a large amount of infrastructure required in order to operate one? Is it that only well-developed/rich nations can effectively generate green hydrogen?
Researchers did mention that with limits of manufacturing and infrastructures of electrolyzers, it will take about 10 more years until green hydrogen can be widespread.
Works Cited:
“From Grey and Blue to Green Hydrogen.” TNO, www.tno.nl/en/focus-areas/energy-transition/roadmaps/towards-co2-neutral-industry/hydrogen-for-a-sustainable-energy-supply/.
7, Renee Cho |January, et al. “Why We Need Green Hydrogen.” State of the Planet, 11 Jan. 2021, blogs.ei.columbia.edu/2021/01/07/need-green-hydrogen/#:~:text=If the electricity is produced,growing interest in green hydrogen.
Carbeck, Jeff. “Green Hydrogen Could Fill Big Gaps in Renewable Energy.” Scientific American, Scientific American, 10 Nov. 2020, www.scientificamerican.com/article/green-hydrogen-could-fill-big-gaps-in-renewable-energy/.
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