Green hydrogen

Green hydrogen is hydrogen that is produced by electrolysis using renewable energies such as wind power and solar power. It plays a central role in the energy transition and contributes to the decarbonization of industry and transport.

Definition
Green hydrogen refers to hydrogen that is produced from water by electrolysis using only renewable energy sources. This hydrogen is climate-friendly and as such is an important resource in the transformation to a more sustainable and lower-carbon economy.

Background / Origin
The EU and Germany have set themselves the goal of being climate-neutral by 2050. In this context, green hydrogen is identified as a key component of the energy transition. In particular, the German government's National Hydrogen Strategy promotes the marketability, industrial production, transportability and usability of green hydrogen. Production from renewable energies, particularly at sea, is a central aspect of this strategy and is supported by projects such as AquaVentus.

The process for producing green hydrogen is based on electrolysis, in which water is split into hydrogen and oxygen. Both drinking water and desalinated seawater can be used. The use of renewable energies is crucial for hydrogen to be classified as green. In addition, the development of alternatives, such as gray, blue and turquoise hydrogen, shows the individual classification depending on the energy sources used.

Properties
Green hydrogen has the physical characteristics of a colorless gas. When producing it, it is crucial that the energy sources used are renewable. Physical properties of hydrogen include

- High energy and thermal conductivity
- Low density
- Combustibility with oxygen

The chemistry of hydrogen makes it a versatile energy carrier. It can be used in a variety of applications, with the type of production (renewable energy versus fossil fuels) influencing its climate friendliness. Only green hydrogen has a positive environmental footprint, which makes it extremely important in the fight against climate change.

Application and importance in the market
Green hydrogen is used in various sectors, particularly in industry for the production of chemicals, plastics and steel. It plays a key role in decarbonization, especially because it makes chemical industry processes more climate-friendly and replaces fossil fuels.

In addition, hydrogen can be used as a fuel in various modes of transportation, such as aviation, shipping and road transport. Especially in areas where electrification is difficult, hydrogen represents an alternative regenerative energy source. Hydrogen can also be used in the form of fuel cells to supply electricity and heat to buildings.

Differentiation from similar terms
- Gray hydrogen: Is obtained from fossil fuels and has a higher CO2 footprint.
- Blue hydrogen: Also produced from fossil fuels, but with CO2 capture and storage.
- Turquoise hydrogen: Is produced by pyrolysis of methane, but is less common.

The distinction is based on the energy sources used in the production process.

Summary
Green hydrogen is a key component of the energy transition and is produced by electrolysis from water and renewable energies. Its importance is evident in the decarbonization of industry and transport. The various forms of hydrogen, especially as green hydrogen, are inextricably linked to the climate targets of the EU and Germany. Its use in various sectors makes it a promising energy source for the future.