A Call for Standardization: Evaluating the True Greenness of Hydrogen Production

The discussion surrounding the various colors of hydrogen used to describe its production methods has led to confusion and an overwhelming number of descriptors. To address this issue, there is a growing need for a standardized carbon intensity scale or scoring system that can be universally applied to assess the environmental impact of hydrogen production and usage. This article proposes the adoption of such a system to provide a clearer understanding of the benefits and drawbacks associated with different hydrogen production methods.

The Current Array of Hydrogen Colors

The hydrogen industry currently utilizes a range of colors to denote the cleanliness or carbon intensity of hydrogen production. However, the proliferation of these colors has made it increasingly complex to navigate and compare various production methods. Here are some common hydrogen colors and their respective production processes:

1. Green Hydrogen: Produced through electrolysis using surplus renewable energy sources, such as solar or wind power, resulting in zero carbon dioxide emissions.

2. Blue Hydrogen: Primarily generated from natural gas using steam reforming, with carbon capture and storage (CCS) employed to trap and store the resulting carbon dioxide.

3. Gray Hydrogen: The most common form of hydrogen production today, created from natural gas without capturing greenhouse gases emitted during the process.

4. Black/Brown Hydrogen: Generated from coal or lignite, these production methods have the highest carbon intensity and are environmentally damaging.

5. Pink/Purple/Red Hydrogen: Produced through electrolysis powered by nuclear energy, offering low-carbon hydrogen production.

6. Turquoise Hydrogen: Under development, this hydrogen is created through methane pyrolysis, potentially with renewable energy sources and permanent carbon storage.

7. Yellow Hydrogen: A relatively new term for hydrogen produced through solar-powered electrolysis.

8. White Hydrogen: Naturally occurring hydrogen found in underground deposits, which is currently not exploited for commercial purposes.

The Case for Standardization

To simplify the evaluation and comparison of hydrogen production methods, a standardized carbon intensity scale or scoring system is proposed. This system would consider the carbon emissions throughout the entire production, storage, transportation, and end-use lifecycle of hydrogen. By providing a universally recognized score, stakeholders can make informed decisions based on the true environmental impact of hydrogen production and usage.

Incorporating all Lifecycle Factors

The proposed scoring system should account for carbon emissions from the hydrogen production process, including any carbon capture and sequestration measures employed. It should also consider the storage and transportation of hydrogen, as well as its ultimate usage as a fuel source or in other applications. Additionally, carbon capture and sequestration efforts related to the use of hydrogen should be factored into the scoring process.

Advantages of a Standardized Approach

The implementation of a universal carbon intensity scale or score for hydrogen offers several benefits. Firstly, it provides a more accurate representation of the environmental impact of hydrogen production methods, allowing for easier comparisons and informed decision-making. Secondly, it instills market confidence by offering transparent and standardized information. Finally, it incentivizes the adoption of cleaner hydrogen production methods by highlighting their superior environmental performance.

Final Thoughts

The current system of using various hydrogen colors to denote production methods has led to confusion and a lack of clarity. By implementing a standardized carbon intensity scale or scoring system, the true greenness of hydrogen production and usage can be assessed in a comprehensive and transparent manner. This approach will enhance decision-making, encourage the adoption of cleaner hydrogen technologies, and contribute to a more sustainable and efficient hydrogen industry.

If you want to learn more about the industrial gas service, you can contact me at 713-383-7010 or email me at

Recent Posts

Contact Us