Hydrogen is the most abundant chemical in the universe, accounting for around 75% of all matter. Most stars, including the Sun, are composed of plasma hydrogen. It is typically found on Earth in the form of molecules such as water and organic compounds.
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What is Green Hydrogen?
The term green hydrogen refers to hydrogen gas produced without releasing any pollutants into the atmosphere, also known as sustainable hydrogen.
Green hydrogen is touted as the main energy source for accomplishing global decarbonization and keeping the climate change pledges made for the year 2050.
The opportunity for using hydrogen to address significant energy challenges has never been higher. The recent performances of electric cars and renewable energy sources have proved policy and technological innovation's capacity to establish a global clean energy sector.
Hydrogen-based fuels can transfer energy from renewable sources across vast distances, from locations with ample energy supplies to energy-starved areas thousands of kilometers distant. Hydrogen is emerging as one of the top possibilities for storing energy from renewable sources.
At the UN Climate Conference, COP26, green hydrogen was mentioned in a variety of pledges to reduce emissions as a way to decarbonize heavy industries, long-haul freight, shipping, and aviation.
Production of Hydrogen
As of 2020, coal gasification, partial oxidation of heavier hydrocarbons, steam reforming of natural gas, and other light hydrocarbons all contribute to the bulk (95%) of hydrogen produced from fossil fuels.
Other hydrogen production techniques include water electrolysis, methane pyrolysis with no CO2 emissions, and biomass gasification.
Since hydrogen is needed for so many crucial chemical reactions, its generation is crucial in any industrialized society. With a compound annual growth rate (CAGR) of 5.4% from 2021 to 2030, the market for hydrogen generation was estimated to be worth US$135.94 billion globally in 2021. It was projected to reach US$219.2 billion by that year.
Natural gas, oil, coal, and electrolysis are the four main methods used to produce hydrogen for commercial purposes. These four methods account for 48%, 30%, 18%, and 4% of the hydrogen produced worldwide, respectively.
The primary source of industrial hydrogen is fossil fuels. For the manufacture of hydrogen, carbon dioxide can be extracted from natural gas with a 70–85% efficiency and from other hydrocarbons with a range of efficiency. The steam reformation of methane or natural gas typically results in the production of bulk hydrogen.
Production of Green Hydrogen
Green hydrogen is formed when water is electrolyzed and split into two halves. Only oxygen and hydrogen are produced by this method without any harmful byproducts. Hydrogen produced is used for energy applications, with oxygen being released into the environment.
Electricity and power are needed for the electrolysis. Renewable energy sources such as the sun or wind fuel this procedure to produce green hydrogen. With no CO2 produced as a byproduct, green hydrogen is the most environmentally friendly choice.
The Green Hydrogen Catapult, a United Nations program, stated that it is virtually tripling its objective for green electrolyzers from 25 gigawatts set last year to 45 gigawatts by 2027 to reduce the price of green hydrogen.
Hydrogen Energy Hubs
Projects that interconnect the production, storage, distribution, and end-use of clean hydrogen are called clean hydrogen hubs. Hydrogen hubs are networks of clean hydrogen producers, prospective clean hydrogen users, and connective infrastructure, all located adjacent to each other.
Several hydrogen-based energy services are integrated under a project called the Hydrogen Hub. These services balance the supply and demand for energy to meet the demands for heat, power, and transportation. The central hydrogen hub shares technology and infrastructure. This clustering generates economies of scale and lowers energy unit costs for each service that shares the infrastructure.
Benefits of Hydrogen Energy Hubs
Although widespread adoption will not happen immediately, the hydrogen-based economy has the potential to replace fossil fuels and fully use the promise of renewable energy technology.
Without supporting infrastructure, hydrogen is not viable, and this infrastructure is not feasible without the right demand. The high initial investment costs of infrastructure need targeted strategies, where projects are first concentrated in areas with the right demand. Hydrogen hubs fund these initial infrastructure investments.
To speed up the use of hydrogen as a clean energy carrier that can carry or store enormous amounts of energy, clean hydrogen hubs will build networks of hydrogen producers, consumers, and local connective infrastructure. These hubs will help reduce carbon emissions in hard-to-reduce industries, improve air quality, expand and diversify the economy, generate new employment, strengthen energy security, and provide companies with more options for growing their bottom lines and cutting emissions.
References and Further Reading
Kakoulaki, G., Kougias, I., Taylor, N., Dolci, F., Moya, J., & Jäger-Waldau, A. (2021). Green hydrogen in Europe – A regional assessment: Substituting existing production with electrolysis powered by renewables. Energy Conversion and Management, 228, 113649. https://www.sciencedirect.com/science/article/pii/S0196890420311766
Mansour-Satloo, A., Agabalaye-Rahvar, M., Mirazaei, M. A., Mohammadi-Ivatloo, B., Zare, K., & Anvari-Moghaddam, A. (2021). A hybrid robust-stochastic approach for optimal scheduling of interconnected hydrogen-based energy hubs. IET Smart Grid, 4(2), 241–254. https://ietresearch.onlinelibrary.wiley.com/doi/full/10.1049/stg2.12035