Green Hydrogen as a Potential Solution for Reducing Carbon Emissions: A Review

Ali Mohamed Elshafei *

Department of Microbial Chemistry, National Research Centre, 33 El Bohouth St. (Former El Tahrir st.), Dokki, Giza, P.O. Box-12622, Egypt.

Rawia Mansour

Egyptian Petroleum Research Institute (EPRI), 1 Elzhoor Region, P.O. Box-11727, Cairo, Egypt.

*Author to whom correspondence should be addressed.


Hydrogen is one of the types of energy discovered in recent decades, which is based on the electrolysis of water in order to separate hydrogen from oxygen. These include grey hydrogen, black hydrogen, blue hydrogen, yellow hydrogen, turquoise hydrogen, and green hydrogen. Generally, hydrogen can be extracted from a variety of sources, including fossil fuels and biomass, water, or a combination of the two.  Green hydrogen has the potential to be a critical enabler of the global transition to sustainable energy and zero-emissions economies. Worldwide, there is unprecedented momentum to realize hydrogen's long-standing potential as a clean energy solution. Green hydrogen is a carbon-free fuel and the source of its production is water, and the production processes witness the separation of its molecules from its oxygen counterpart in the water by electricity generated from renewable energy sources such as wind and solar energy. Green hydrogen is one of the most important sources of clean energy, which may be why it is called green hydrogen. It is a clean source of energy, and its generation is based on renewable energy sources, so no carbon gases are released during its production. Green hydrogen produced by water electrolysis becomes a promising and tangible solution for the storage of excess energy for power generation and grid balancing, as well as the production of decarbonized fuel for transportation, heating, and other applications, as we shift away from fossil fuels and toward renewable energies. Green hydrogen is being produced in countries all over the world because it is one of the solutions to reducing carbon emissions, and it is clean, environmentally friendly energy that is derived from clean renewable energy. However, due to the combination of renewable generation and low-carbon fuels, projects for the production of green hydrogen are very expensive. The goal of this review is to highlight the various types of hydrogen, with a focus on the more practical green hydrogen.

Keywords: Green hydrogen, electrolysis, renewable energy, hydrogen types, economics

How to Cite

Mohamed Elshafei , A., & Mansour , R. (2023). Green Hydrogen as a Potential Solution for Reducing Carbon Emissions: A Review. Journal of Energy Research and Reviews, 13(2), 1–10.


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Dawood F, Anda M, Shafiullah GM. Hydrogen production for energy: An overview. International Journal of Hydrogen Energy 2020;45(7):3847-3869. Available:

Al-Breiki M, Bicer Y. Investigating the technical feasibility of various energy carriers for alternative and sustainable overseas energy transport scenarios. Energy Convers Manag 2020; 209:112652. Available:

Tarkowski R. Underground hydrogen storage: characteristics and prospects. Renew Sustain Energy Rev 2019;105: 86-94; Available:

Wang Q, Xue M, Lin BL, Lei Z, Zhang Z. Well-to-wheel analysis of energy consumption, greenhouse gas and air pollutants emissions of hydrogen fuel cell vehicle in China. Journal of Cleaner Production 2020;275:123061.

ISSN 0959-6526; Available:

Staffell I, Scamman D, Abad AV, Balcombe P, Dodds PE, Ekins P, Shah N, Ward KR. The role of hydrogen and fuel cells in the global energy system. Energy Environ. Sci. 2019;12(2):463-491. Available:http://doi:10.1039/C8EE01157E.

IRENA; Hydrogen from Renewable Power: Technology Outlook for the Energy Transition, Tech. Rep. International Renewable Energy Agency; 2018. Available:

Rabiee A, Keane A and Soroudi A. Technical barriers for harnessing the green hydrogen: A power system perspective, Renewable Energy. 2021;163:1580- 1587.

ISSN 0960-1481 Available:

Renee C. 2021. Why we need green hydrogen. State of the Planet; 2021. Retrieved 22 January 2022.

Purtill J. What is green hydrogen, how is it made and will it be the fuel of the future?. ABC News. Australian Broadcasting Corporation; 2021. Archived from the original on 29 January 2021. Retrieved 4 February 2021.

Miha J, Narita J, Piria R, Samadi S, Prantner M, Crone K, Siegemund S, Kan S, Matsumoto T, Shibata Y, Thesen J. The role of clean hydrogen in the future energy systems of Japan and Germany. Berlin: adelphi. Adelphi Wuppertal Institute dena. IEEJ; 2019.

Bruce S, Temminghodd M, Hayward J, Schmidt E, Munnings C, Palfreyman D, Hartley P. Australia’s National Hydrogen Roadmap’, CSIRO, Energy and Futures, Australia; 2018. Available:

Ortigao FR. White hydrogen BW3rev; Presentation of BW3 conference.

Available:http:doi.10.13140/RG.2.2.15364. 86409

El-Shafie M, Kambara S, Hayakawa Y. Hydrogen production technologies overview. Journal of Power and Energy Engineering. 2019;7(1). Available:https://doi:10.4236/jpee.2019.71007

Hague O. What are the 3 Main Types of Hydrogen? [online] Available: [Accessed 03 December 2021].

Giovannini S. 50 shades of (grey and blue and green) hydrogen; 2020. Available: [Accessed 03 December 2021]

Ibeh B, Gardner C, Ternan M. Separation of hydrogen from a hydrogejn/methane mixture using a PEM fuel cell, International Journal of Hydrogen Energy. 2007;32(7): 908-914. Available:https://doi:10.1016/J.IJHYDENE.2006.11.017Corpus ID: 96649640

Deloitte. Investing in hydrogen – Ready, set, net zero’; 2020.

Ghazaie SH, Sadeghi K, Sokolova E, Fedorovich E, Shirani A. Nuclear desalination in Iran, current status and perspectives. E3S Web of Conferences 2019;140,04001. Available:; EECE-2019

IAEA (International Atomic Energy Agency), New Technologies for Seawater Desalination Using Nuclear Energy TecDoc, Vienna; 2015.

Sapienza R. Turquoise Hydrogen Energy Summary; 2021.

Dini D, Hydrogen production through solar energy water electrolysis, International Journal of Hydrogen Energy. 1983;8(11–12):897-903.

ISSN 0360-3199 Available: 99(83)90113-1

Kim KS, Seo J-H, Nam J-S, Ju WT, and Hong S. Production of hydrogen and carbon black by methane decomposition using DC-RF hybrid thermal plasmas. Plasma Science, IEEE Transactions on 2005;33(2):813-823. Available:https://doi:10.1109/TPS.2005. 844526

Barreto LA, K. Makihira K, and Riahi, The hydrogen economy in the 21st century: A sustainable development scenario. In Press, International Journal of Hydrogen Energy 2003;28(3):267-284.

ISSN 0360-3199 Available:

Azinheira G, Segurado R, Costa M. Is Renewable Energy-Powered Desalination a Viable Solution for Water Stressed Regions? A Case Study in Algarve, Portugal. Energies. 2019;12(24):4651.


Bezdek, RH. The hydrogen economy and jobs of the future, Renew. Energy Environ. Sustain. 2019;4.


Cavana M and Leone P. (2021). Solar hydrogen from North Africa to europe through greenstream: A simulation-based analysis of blending scenarios and production plant sizing’, International Journal of Hydrogen Energy 2021;46: 22618-22637; Available:

BNEF. Hydrogen Economy’ Offers Promising Path to Decarbonization. [online]; 2020. Available: [Accessed 22 December 2021].

Ibrahim JM, Moussab H. Recent advances on hydrogen production through seawater electrolysis, Materials Science for Energy Technologies.2020;3:780-807. Available:

Kalamara CM, Efstathiou AM. Hydrogen Production Technologies: Current State and Future Developments, Power Options for the Eastern Mediterranean Region, Conference Papers in Energy; 2012. Limassol, Cyprus. Conference Paper | Open Access; Volume 2013 | Article ID 690627 Available:

Guo Y, Li G, Zhou J, Liu Y. Comparison between hydrogen production by alkaline water electrolysis and hydrogen production by PEM electrolysis’, Earth and Environmental Science 2019;371. Available:https://doi:10.1088/1755-1315/ 371/4/042022.

Khan MA, Al-Attas T, Roy S, Rahman MM, Ghaffour N, Thangadurai V, Larter S, Hu J, Ajayan PM, Kibria MG. Seawater electrolysis for hydrogen production: A solution looking for a problem? Energy & Environmental Science 2021;14(9):4831-4839. Available:https://doi:10.1039/d1ee00870f

Rao PMP, Jhala PP. Green Hydrogen-Energy source of the future; An Analysis of the Technology Scenario; 2021. Available:https://doi:10.13140/RG.2.2.299 47.64807

Aakko-Saksa PT, Cook C, Kiviaho J, Repo T. Liquid organic hydrogen carriers for transportation and storing of renewable energy – Review and discussion. J. Power Sources 2018:396;803–823. Available:

Agarwal AK, Gautam A, Sharma N, Singh AP. Methanol and the alternate fuel economy. ISBN 978-981-13-3286-9 ISBN 978-981-13-3287-6 (eBook); 2019. Available:

Stevenson EV. Sustainable Hydrogen Delphi Survey Round 1 ‐ Participant Report, Low Carbon Research Institute; 2011.