The colours of hydrogen

There are different kinds of hydrogen. The different methods of producing the gas emit different amounts of CO2. Depending on the production methods, hydrogen can be green, turquoise, blue or grey.

For hydrogen to support climate targets, it is essential that it be generated in a climate-neutral manner, without causing additional CO2 emissions. This can only be achieved by green hydrogen.

Green hydrogen

Green hydrogen is produced by the electrolysis of water, meaning the breakdown of water molecules into the two individual elements hydrogen and oxygen. Only electricity from renewable energies is used. This way no CO2 is produced, making the generated hydrogen climate neutral. This is how hydrogen should ideally be produced.

In order to produce large amounts of green hydrogen, we need considerably larger electricity generation capacities from renewable energies. In addition, electricity prices must be affordable so that green hydrogen is also economically competitive. An important lever for achieving this would be the reform of the charges and levies on electricity.

Turquoise hydrogen

Turquoise hydrogen is created when natural gas is broken down with the help of methane pyrolysis into hydrogen and solid carbon.

CO2 is not directly generated; instead, natural gas, which is difficult to obtain, is used as a raw material.

Blue hydrogen

Blue hydrogen is produced by what is known as natural gas steam reforming, meaning the separation of natural gas into hydrogen and CO2.

The CO2 is not released into the atmosphere afterwards but is directly stored (CCS = carbon capture and storage).

Grey hydrogen

Grey hydrogen is obtained by steam reforming fossil fuels such as coal or natural gas.

Per tonne of hydrogen, ten tonnes of CO2 are generated as waste which is released unused into the atmosphere.