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Status: 08/22/2022 5:29 p.m
Hydrogen should make Germany more climate-friendly and independent of fossil fuels. The problem: The production of hydrogen is energy-intensive – and creates new dependencies on other countries.
In the future, hydrogen will play an elementary role in many areas – especially where fossil fuels cannot be replaced by green electricity in the foreseeable future. With over 60 lighthouse projects, Germany wants to become the number one hydrogen country and advance important technologies. But still many problems are not solved.
Producing hydrogen costs energy
Hydrogen can store a lot of energy, more than fossil fuels: One kilogram of hydrogen provides about as much energy as 2.8 kilograms of petrol. But in turn, producing hydrogen requires a great deal of energy. Because hydrogen is a gas that only occurs in bound form in nature, for example in water or natural gas. So it has to be detached from this connection.
So far, however, the energy for this process in Germany has mainly come from fossil fuels such as oil and natural gas. This is anything but climate-friendly: the production of this so-called “grey” hydrogen produces a lot of climate-damaging CO2. So far, however, it was cheaper, but that is currently changing due to the energy crisis, explains physics professor Tabea Arndt from the Karlsruhe Institute of Technology (KIT), who researches hydrogen technologies: “Due to the current energy shortage, the situation has arisen that the cost of gray hydrogen is greater have become than the cost of hydrogen from green renewable energy sources.”
Too little climate-friendly hydrogen
By 2030, the federal government wants to decisively advance the production of climate-friendly “green” hydrogen with the National Hydrogen Strategy. This is obtained from water by means of electrolysis: Water is broken down into its components hydrogen and oxygen by supplying sustainably generated electricity from the wind or sun.
So far there is hardly any green hydrogen in Germany, but it is becoming more and more popular. It is to be used primarily where a lot of energy is needed and there is no electrical alternative, for example in the energy-intensive steel or chemical industry. There he should reduce CO2 emissions. Hydrogen technology is also being developed as a fuel for aircraft, trucks and ships, for example, because the batteries would be too large and heavy. “If we want to fully decarbonize traffic, i.e. want to do without fossil fuels, then we also need a fuel that can also move large vehicles if batteries or overhead lines are not possible,” says Arndt.
Limited use in traffic
Hydrogen currently plays hardly any role in transport, and that will remain the case for the time being. According to the current state of knowledge, a dominant role in road traffic seems less likely due to the technical development of batteries and fast charging as well as the overall costs, admits that Fraunhofer Institute for Systems and Innovation Research a. At the beginning of 2021, there were just about 25,000 hydrogen fuel cell cars on the roads worldwide. In contrast, there are currently more than 15 million battery-powered electric and plug-in hybrid vehicles on the road.
New dependencies from abroad
Current hydrogen consumption is around 50 to 60 terawatt hours. Researchers have different estimates of how great the need will be in the future. That also depends on how cheap the manufacturing process is: The figures range from 40 to 180 terawatt hours. However, the experts agree that Germany can never meet this demand alone and that imports from South and West Africa or Australia are required.
New dependencies from abroad are therefore to be expected, says Arndt: “As an industrial nation, Germany will probably never be able to supply itself with green energy independently. This means that we will remain an import nation for primary energy sources and thus also an import nation for green hydrogen .”
transportation necessary
It is also still unclear how the hydrogen will get to where it is needed: more by pipeline or by ship? Physicist Arndt and her team at KIT are researching this. Her vision is a pipeline that transports both: “A special development at our institute is a hybrid energy transmission line that can transport electrical energy and liquid hydrogen,” she explains. “This is particularly helpful if you have a consumer, for example an airport, that needs liquid hydrogen but also electrical energy, so that you can use the same route for both.”
However, the liquefaction of hydrogen for transport also requires a lot of energy, which is why in the future it will be necessary to calculate exactly where hydrogen is really worthwhile and where not. All in all, Arndt calls for better framework conditions so that hydrogen can really become a key energy carrier of the future: “With fossil fuels, the environmental damage is not priced in, while with green hydrogen we have priced in the entire circular economy from the start.”
Therefore there is a large price difference between these two energy sectors, explains Arndt. “In order to break this dilemma, the framework conditions should be set accordingly, be it that products made from green steel are taxed less or that tolls for trucks that run on hydrogen are reduced.”