Mange taler om brint som fremtiderns bedste energiform, men det er kun muligt, hvis der produceres grøn brint, og det er foreløbig en dyr og besværlig proces, skriver Deutsche Bank i en analyse. Tyskland og EU har udviklet strategier for grøn brint som fremtidens energikilde, men det er et langtidsprojekt.
Green hydrogen as a source of energy: The trillion-euro question
If green hydrogen is to make a significant contribution to climate-friendly energy supply in the future, it will need to be produced (1) in large quantities, (2) cost-efficiently and (3) using low-carbon methods.
Any solutions to these problems have remained in the realm of theory so far. Additional challenges arise in connection with the transport and storage of hydrogen. Initially, green hydrogen will be used to satisfy large-scale demand at specific locations, for example in energy-intensive industries. Like many other climate-friendly technologies, hydrogen will need government subsidies in the beginning.
In the longer run, hydrogen might be used in the transport sector as well, for example as aircraft or ship fuel. In theory, hydrogen is highly versatile. However, it is quite expensive, too. That is one reason why hydrogen will probably make only a small contribution to the national and global energy transition in the next one or two decades.
Hopes are high that hydrogen may become the energy source of the future. Both the German government and the EU Commission presented new strategies for using hydrogen as a source of energy in summer 2020. The German government’s National Hydrogen Strategy says that hydrogen “will play a key role in enhancing and completing the energy transition”.
Policymakers regard green hydrogen as a potential “silver bullet”
In contrast to crude oil, coal, natural gas, nuclear fuels or biomass, hydrogen is not a primary source of energy and mostly occurs in bound form (usually water or hydrocarbons, such as coal, oil or natural gas).
If hydrogen is to be used as a source of energy, it thus will need to be produced first – and that process requires energy. Today, this energy is usually provided by fossil fuels. The resulting hydrogen is called “grey hydrogen”.
The National Hydrogen Strategy calls for “green” hydrogen, which uses electricity from renewable sources for the electrolysis of water. The procedure yields liquid or gaseous downstream products which can be used as energy source (power-to-x, “P2X”). In this way, hydrogen may close one of the gaps in the energy transition strategy. Remember, for example, that (at least for the foreseeable future) it appears impossible or prohibitively expensive to have some types of vehicles, such as aircraft or ships, run on electricity. Green hydrogen may also offer a number of industrial sectors an opportunity to reduce (process-inherent) carbon emissions. This applies, for example, to the metals industry, the chemical industry or building materials production. And finally, it is theoretically possible to use green hydrogen for heating purposes.
Federal government is not exuberant
That is the theory. There is no doubt that there are major practical hurdles. For that reason, the federal government’s National Hydrogen Strategy does not claim that hydrogen will become a “game changer” in the energy transition during the coming years. The strategy also points out that Germany will probably import a large share of any future hydrogen supplies from countries which offer more favourable conditions for the production of green hydrogen. This means that hydrogen is unlikely to make a significant contribution to energy self-sufficiency.
Technological progress, but no quick solutions
It may appear counterproductive to emphasise during climate and energy-policy discussions what is not (yet) possible or which hurdles need to be overcome. However, wise political decisions need to be based on a well-founded assessment of the potential contributions of individual technologies towards resolving the climate and energy problem. In this process, policymakers need to consider not only technological feasibility issues, but also subsequent economic and social costs in order to keep public expectations realistic.
Even if green hydrogen will remain expensive for now and cannot make a major contribution to climate-neutral energy, there are reasons to be optimistic. We are likely to see technological progress at all stages of the process. Costs for running electrolysers will decline on the back of scale effects, and hydrogen may be transported in existing pipelines (via the natural gas network). And instead of liquid hydrogen, ammonia (NH3) may be transported by ship over long distances.
Original in German published on February 1, 2021: ˮGrüner Wasserstoff als Energieträger: Die Billionen-Euro-Frageˮ
