Hydrogen – A technology for the future:

Hydrogen – multifaceted applications

Hydrogen, “H”, is by far the most common chemical element in the universe. On Earth, hydrogen is practically non-existent in its elemental form, but it is present in many compounds. In everyday life, we encounter hydrogen first and foremost in combination with the element oxygen “O”. Together they become water – “H₂O”.

The process to separate hydrogen from oxygen is referred to as electrolysis. So-called electrolysers are technical devices that can separate water into hydrogen and oxygen with the help of electric current. One of the world’s largest hydrogen electrolysis plants is currently being built in Wesseling in North Rhine-Westphalia.

Its many uses make hydrogen and its applications key technologies in the energy transition. Hydrogen can be used as an energy storage medium as well as an energy carrier to drive engines, machines and heating systems. The central areas of application for hydrogen are in the following areas.

Mobility

Modern (engine-powered) mobility is electric. The fossil fuels of petrol and gas are finite and pollute the climate with excessively high CO₂ emissions. As electric vehicles become increasingly popular on the market, they will gradually replace conventional internal combustion engines.

Electric mobility is the key technology for shaping a sustainable transport system. The electricity required by electric vehicles is provided either by batteries or fuel cells. The fuel cell converts hydrogen directly into electricity.

Battery or fuel cell-powered electric mobility not only affects our cars, but a wide range of means of transport, including:

• Buses: Run by private companies and public transport authorities alike. Hydrogen buses have already been in use in public transport for several years.
• Commercial and special vehicles: Trucks and vans of all sizes, emergency vehicles for the fire brigade, paramedics and other rescue services, but also tractors, forklifts, waste disposal trucks and many other vehicles can be powered by hydrogen.
• Trains: Initial practical trials with so-called hydrogen multiple units powered by electric motors are promising and show that hydrogen also has a future in rail transport. Hydrogen multiple units are already in regular service. Since 17 September 2018, two hydrogen trains from Alstom have been running on the route between Cuxhaven and Buxtehude via Bremerhaven and Bremervörde.
• Aircraft: Hydrogen can replace petroleum-based jet fuel. Aircraft can also be powered by hydrogen. After successful test flights, the first four-seater passenger aircraft, powered solely by a hydrogen fuel cell battery system was presented at its home airport in Stuttgart on 11 December 2020.
• Ships: Hydrogen and fuel cell technology can be used in the maritime sector for emission-free propulsion and for the on-board power supply.

Hydrogen: Key technology for sector coupling

Sector coupling connects the energy sectors of electricity, heat and mobility. It is considered a core concept for a successful energy transition. Its many uses as a storage medium and fuel make hydrogen a key technology for the energy transition.
Various concepts and technologies are suitable for coupling the sectors. The most promising approach today is the power-to-gas concept. Power-to-gas describes the generation of hydrogen or methane by means of electricity. The green hydrogen generated by renewable energies can then be stored and used in a variety of ways in all sectors.

• In transport: In combination with the fuel cell, hydrogen can be used as a fuel in almost all forms of mobility.
• In buildings: In apartments and houses, hydrogen can be used as an admixture or as a “synthetic natural gas” to help heat buildings.
• In industry: In the chemical industry, hydrogen forms the basis for many chemical value chains. For energy-intensive industries such as the metal processing industries or the cement industry, green hydrogen is the bearer of hope for a comprehensive decarbonisation of the industries.
• As energy storage: One of the great challenges of the energy transition is the storage of renewable energy. Hydrogen is an ideal energy storage medium. Rather than storing excess electricity in batteries, electrolysers can be turned on when needed to convert the electricity into renewable gas. Such green hydrogen can be very easily stored in pressurised tanks or, theoretically, in caverns. There are currently numerous projects and test projects underway to examine the storage of hydrogen in cavern storage facilities in salt rock.
  Another major advantage of hydrogen is that it can be transported via the already existing and widely networked gas infrastructure throughout Germany and distributed equally to private households as well as industries alike.
  Hydrogen via power-to-gas is the only technology available today that makes both seasonal storage of electricity and its use in all energy-intensive sectors possible.

Hydrogen Strategy of the Federal Government

A successful energy transition means balancing security of supply, affordability and environmental compatibility with innovative and intelligent climate protection. Hydrogen is a versatile energy carrier, energy storage medium and an essential element of sector coupling.

With the National Hydrogen Strategy , the German government is creating a holistic framework for action for the future production, transport, use and further application of hydrogen and consequently for corresponding innovations and investments. It defines the steps that are necessary to contribute to achieving the climate targets, to create new value chains for the German economy and to further develop international energy policy cooperation.