Types of Hydrogen Energy : What’s Behind Grey, Blue and Green Hydrogen?

We have discovered different colours of hydrogen energy. Let’s explore more about functions and significant differences of each colour of them.

Grey Hydrogen

Grey hydrogen is the most common form of hydrogen. It is produced using fossil fuels, and during the process, carbon dioxide is released but not collected. The process in generating the natural gas or methane is known as “steam reforming”.

As it is the most common type of hydrogen, what about the cost? Talking about the cost, grey hydrogen is frequently used in the chemical industry to produce fertiliser and refine oil because it is reasonably affordable.

Then, is grey hydrogen environmentally friendly? As the world transitions away from fossil fuels, grey hydrogen is seen as a “bridging” energy source. Unfortunately, like oil drilling or coal mining, it has a negative overall influence on the climate.

Blue Hydrogen

The term “blue hydrogen” refers to natural gas-derived hydrogen that is backed by carbon capture and storage. According to Brunel (2021), the same method as grey hydrogen is used in blue hydrogen. However as for blue hydrogen, the carbon is caught and stored. It does not escape into the environment.

Compared to grey hydrogen, this type of hydrogen requires a significant price increase. Although there are greater technical difficulties as a result, it becomes considerably more environmentally beneficial.

Due to it producing much lower carbon dioxide (CO2) emissions than grey hydrogen, which makes it more environmentally friendly overall, blue hydrogen is currently gaining attention as a practical option.

Green Hydrogen

The hydrogen produced with no damaging greenhouse gas emissions is called “green hydrogen.” It is also called clean hydrogen as it has been created using energy that is clean and abundant from renewable energy sources, including solar or wind power.

Green hydrogen is formed when water is electrolyzed and split into two halves — oxygen and hydrogen. In spite of its eco-friendly process, green hydrogen has been making up a small portion of hydrogen due to the high cost of production.

Even so, the World Economic Forum (2021), has stated that green hydrogen is now viewed by many industries as the greatest solution to balance out the erratic nature of renewable energy sources. It is able to preserve extra energy during periods of low demand to be returned to the grid during times of high demand.

Doren is currently working on producing the green hydrogen to apply in various fields.

1. Green hydrogen as fuel

• Vehicles, trains, aircrafts, lorries, buses and even maritime transport.

2. Green hydrogen in industry

• Chemical industry
• Petrochemical industry (produce petroleum products)
• Steel industry

3. Domestic use

• Provides electricity and heat to households