The world is at a critical juncture in its fight against climate change. Governments, executives, and researchers worldwide are accelerating the energy transition to align with the Paris Agreement's targets. The goal is to limit global warming to well below 2°C while pursuing efforts to limit the increase to 1.5°C. This requires replacing legacy systems powered by fossil fuels with low-carbon energy sources such as renewables.

Emergence of Green Hydrogen

Among these, green hydrogen is emerging as a promising solution. It could overcome the limitations of other renewable sources and become the critical clean hydrogen supply option in the long run, being both economically viable and truly sustainable.

Understanding Hydrogen and its Various Forms

Hydrogen is a versatile energy carrier that can address various critical energy challenges. Today, it is mainly used in the refining and chemical sectors and produced using fossil fuels such as coal and natural gas, thus responsible for significant annual carbon dioxide (CO2) emissions.

Production Pathways of Different Hydrogen Types

However, not all hydrogen is created equal. There are different "shades" of hydrogen based on their production methods:

  • Brown hydrogen is produced using coal, and the emissions are released into the air.
  • Grey hydrogen is produced from natural gas, where the associated emissions are released into the air.
  • Blue hydrogen is produced from natural gas, where the emissions are captured using carbon capture and storage.
  • Green hydrogen is produced from electrolysis powered by renewable electricity.

Each type of hydrogen ends up as the same carbon-free molecule. However, their diverse production pathways lead to varying greenhouse gas emissions like CO2 and methane (CH4).

Blue hydrogen follows the same process as grey. Still, it includes additional technologies necessary to capture the CO2 produced when hydrogen is split from methane (or coal) and store it long-term.

Traditionally produced from CH4, Grey hydrogen is split with steam into CO2 – the main culprit for climate change – and H2, hydrogen. It has increasingly been produced from coal, with significantly higher CO2 emissions per hydrogen unit.

Green hydrogen is produced by splitting water into hydrogen and oxygen using renewable electricity. This process offers a sustainable pathway compared to grey and blue hydrogen.

Potential Applications of Green Hydrogen

The potential applications for green hydrogen are vast. It can be used in fuel-cell hydrogen electric cars and trucks, container ships powered by liquid ammonia made from hydrogen, and "green steel" refineries that use hydrogen as a heat source instead of coal. It can also power electricity turbines during peak demand times to help firm the electricity grid and substitute natural gas for home cooking and heating.

Economic Viability and Sustainability of Green Hydrogen

Versatile and sustainable, green hydrogen is set to be a key player in the clean hydrogen supply chain. The global hydrogen market, valued at $155 billion in 2022, is projected to grow significantly, with green hydrogen's share expected to increase. The United Arab Emirates, for instance, aims to hold a fourth of the global low-carbon hydrogen market by 2030. These developments underscore the growing interest in green hydrogen as a viable solution for achieving carbon neutrality and a promising option for the future of clean energy.

Conclusion

In conclusion, green hydrogen emerges as a critical player in the global effort to combat climate change. Its versatility and sustainability make it a promising solution for replacing carbon-intensive energy sources. Its potential in fuel-cell vehicles, green steel production, and grid management highlights its role in diverse sectors as the world seeks to limit global warming in line with the Paris Agreement. Green hydrogen's economic viability and environmental benefits position it as a crucial element in the future of clean energy and carbon neutrality.