Hydrogen is the lightest and most abundant chemical element in the universe. On Earth, you can find it rarely in its pure form, but mostly as part of a compound (e.g. water).
Hydrogen has been discovered in the 18th century, and for over 100 years hydrogen it has played numerous roles, such as coolant or in the semiconductor industry.
Its innovative potential as an energy source is coming more and more to the fore in our time: In order for us to rely completely on renewable energy, hydrogen is necessary as it permits the storage and transportation of primary energy (e.g. solar and wind power).
Renewable energy is abundant in principle, but is not always available precisely where and when it is needed. These mismatches between supply and demand can be bridged with the help of the hydrogen as an energy vector. It is a complement to electricity as a means of transporting energy, which is the usual method of choice and will remain so.
In addition to the technical facilities, a primary energy source is required for the production of hydrogen. In order to provide a sensible replacement for fossil fuels, no energy from fossil energy sources should be used, but rather alternative, renewable energy sources such as hydropower, solar energy, wind power or biomass, producing "green" hydrogen.
With the necessary equipment, hydrogen can be produced and stored at almost any location, allowing renewable energy sources be used much more efficiently. In addition, hydrogen can replace oil (and natural gas) as a fuel in the mobility sector. This not only avoids the environmental and health problems associated with the use of petroleum, but also reduces dependence on oil imports and promotes local added value.