Frequently-asked questions (FAQ) about hydrogen

What is hydrogen?

Hydrogen is a chemical element that occurs in nature, for example in combination with atoms of oxygen as water - H2O. The chemical element is abbreviated as H.

Green hydrogen?

Green hydrogen is produced by the electrolysis of water. With green hydrogen, the electricity for electrolysis comes exclusively from renewable sources. As a result, the electricity used is free of CO2 and so is the production of hydrogen. This does not depend on the electrolysis technology used.

Where can hydrogen be used?

Hydrogen offers many possible applications in centralized and decentralized power generation. But it can also be used to power vehicles, to produce alternative fuels, combustibles and gases, for long-term storage, and as a raw material for industrial (especially chemical) processes.

Why hydrogen?

The significance of green hydrogen stems from the possibility of storing it in large quantities, transporting it and flexibly transforming it into electricity. Green hydrogen offers the prerequisite for advancing the coupling between the heat, transport and energy sectors that is necessary for the energy revolution.

Hydrogen, fuel cell, electrolysis?

Electrolysis is necessary to produce hydrogen from water (H2O) and electricity. In this process, H2O is separated into H2 and O2. The fuel cell is necessary to produce electricity from H2 again (e.g. to drive an electric motor). For this, H2 (from a tank system) is converted into H2O using O2 from the air.

Hydrogen – is its efficiency is too low?

If you compare the storage of electricity in hydrogen with the storage in a battery, you come to the conclusion that there are higher losses with hydrogen due to the conversion steps (electrolyzer and fuel cell). To properly qualify this, the future of the overall energy system must be considered. Due to the steadily growing share of fluctuating renewable energies, green electricity must be made storable and transportable in situations of over- and underproduction. To meet the global energy demand for clean electricity, it will be necessary to transport green electricity from countries with favourable conditions for green electricity production to industrialized countries with less favourable conditions for green electricity production, where larger quantities can be produced at significantly lower prices due to higher efficiency. Green hydrogen will thus be needed as an energy source in any event and will thus be available for use in fuel cell vehicles. For economic analysis, the factors of charging time, investment in infrastructure and flexibility must also be taken into account.