Interview Prof. Reimann

Hello Prof. Reimann, this year the German government published a National Hydrogen Strategy. Why is this energy carrier now becoming the focus of industry and research?

Reimann: Hydrogen is a very interesting energy carrier. It is ecological and can be produced very well with known processes, but also with new ones that are to be developed. It can be stored, transported, converted into various energy media and used in many different ways. Hydrogen is therefore not only a key element in the energy transition, but also in the mobility transition. In addition, hydrogen is an important chemical element in many process technologies - this is where the interface with the process engineering industry exists. However, international research projects on hydrogen have been ongoing for at least 20 years.

Hydrogen is an important energy carrier for realizing the energy transition. In which areas is this energy carrier used?

Reimann: Mostly hydrogen is discussed in connection with mobility issues. You hear a lot about cars, trains or buses that run on hydrogen. In reality, the field of application is much broader.

Hydrogen is also a highly interesting storage medium in connection with the use of renewable energies such as sun and wind. They are volatile energy sources that fluctuate greatly and therefore require storage. Hydrogen can store energy. There are already very interesting energy supply concepts for private homes today, where the surplus of sun and wind is exploited in summer and hydrogen is produced from it. This is stored and used in winter to generate electricity and heat for the house again. Because: Hydrogen can be stored easily and for a long time and converted back into different quantities such as heat or electrical energy.

Where else is hydrogen used?

Reimann: Another application is in process technologies in industry. For example, there are processes in which a lot of carbon dioxide is emitted. This includes the building materials industry. Processes for the production of lime or cement generate a lot of C02. The companies now have to contribute to the costs of the emissions with C02 certificates and pass these costs on to the price of the building materials. The exhaust gases from the manufacturing processes can be mixed with hydrogen, which binds the C02. This produces methane, which in turn can be used as a useful gas in the processes.

Stationary applications are further possible uses of hydrogen. One can realize emergency power generators on the basis of hydrogen. One has to imagine hydrogen tanks for this purpose. With the addition of oxygen, fuel cells convert the hydrogen into electrical energy. This can be used, for example, to build local power supplies for remote consumers. Scientific measuring stations but also IT systems are part of this.

Research on hydrogen is being carried out at the TU Ilmenau. What makes hydrogen so interesting for university research?

Reimann: The research field of hydrogen is so interesting for universities because you have to look at the entire spectrum, starting with the scientific fundamentals and ending with engineering systems. You can involve a great many disciplines because there are many detailed topics to be researched. And you have to work together on an interdisciplinary basis. The teams are made up of scientists from different disciplines and faculties. At the TU Ilmenau, many disciplines are involved in research and work together on an interdisciplinary basis. I see enormous research potential at the TU Ilmenau in the field of engineering. That is why central coordination via the cross-faculty institutes and competence centres at the TU Ilmenau is very important.

How long have scientists at the TU Ilmenau been working on hydrogen?

Reimann: At the TU Ilmenau we have been researching this topic for at least 15 years.

Researchers at the TU Ilmenau have succeeded in setting an international world record for solar water splitting. How is hydrogen produced in this process?

Reimann: Most hydrogen produced today is produced in so-called electrolyser plants. In this process, water is split into hydrogen and oxygen with the addition of electrical energy.

Photo-electrochemical generation, also known as solar water splitting, uses solar energy to split water. Photosynthesis is technically reproduced. Prof. Thomas Hannappel works in this field at the Department of Fundamentals of Energy Materials. Prof. Andreas Bund is also working on solar water splitting in the Department of Electrochemistry and Electroplating.

How far has research on hydrogen progressed at other Thuringian universities, and could you imagine collaborating with them?

Reimann: The Friedrich Schiller University of Jena with its high-performance institutes is also researching hydrogen, but clearly with a focus on the natural sciences. I believe that a collaboration could be very fruitful here.

At the Bauhaus University Weimar there is a professorship for energy systems, headed by Prof. Mark Jentsch. He is working on urban infrastructure systems of the future. Especially in urban agglomerations, the topic of regenerative energy and the use of hydrogen plays a very important role. Prof. Jentsch coordinates some activities on hydrogen in Thuringia and I myself cooperate with him in some projects. The question of how sustainable mobility and energy supply can be integrated into our cities and rural structures is very relevant here.

In addition, application-oriented research institutes such as the Fraunhofer Institutes as well as universities of applied sciences are pursuing detailed questions on the research topic of hydrogen in particular.

What is the situation in Thuringia's industry?

Reimann: It is very interesting to observe that in the field of industry as well as in the municipal sector very many players have taken up the topic of hydrogen. In Thuringia we have companies that develop and manufacture, for example, electrolysers, line electronics, control and regulation technology, sensors, or hydrogen filling stations for passenger cars. In Ilmenau alone, there are two companies that develop and manufacture power electronics systems that can be used to operate electrolysers and fuel cells.

The interview was conducted by Eleonora Hamburg.