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Large-scale trial:
truck with hydrogen tanks leaves the power-to-gas facility in the Mainz energy park
Photo: Andreas Arnold / dpa
What can hydrogen do?
Hydrogen (in gas form H2) is the most common element in the universe, it has a high energy density.
If it is burned or otherwise converted to release this energy, only water vapor and heat are produced instead of harmful exhaust gases - these are the outstanding advantages.
However, H2 must first be obtained, usually by separating it from oxygen in the water (electrolysis).
Because it takes up an enormous amount of space, hydrogen is usually compressed or liquefied for storage and transport.
All of these processes cause energy losses.
And hydrogen is highly explosive, so it has to be specially secured.
Where is hydrogen used today?
For a future technology, hydrogen is already quite present.
According to the federal government, Germany currently consumes around 55 terawatt hours of hydrogen annually, the majority of which is either in the chemical industry for the production of ammonia (mostly as a fertilizer) or in oil refineries as a by-product and at the same time an aid for the production of fuels.
Hydrogen can also be burned directly in engines, for example as rocket fuel.
Fuel cells that drive electric motors with the help of hydrogen are rather rare, which saves space but leads to further energy losses.
After decades of research, however, the first cars are already on the market.
Some countries such as Japan or South Korea are already relying on large-scale replacing natural gas as a heat source or process gas, for example in the chemical industry, with hydrogen.
The existing gas infrastructure can at least partially be used for this.
What makes hydrogen a hope for the future?
For a climate-neutral future, hydrogen makes sense, "where electrification is not economically or process-technically difficult," says Daniel Kronenwett, partner of the management consultancy Oliver Wyman, to manager magazin.
As a rule, climate protection is more efficient if you rely on electricity from renewable sources without any further detours.
But this is technically out of the question for large parts of the economy.
Above all, the steel and cement industries as large CO2 emitters, whose products are still needed, are still looking for a way to fulfill the promise of climate neutrality.
Burning hydrogen is now the only plausible answer for most companies - but the technology is only in the pilot stage.
Veronika Grimm
(49) is convinced
that the goal of zero CO2 emissions will be impossible to achieve by the middle of the century without hydrogen
.
Whether hydrogen is also used to heat buildings or industrial plants, as fuel for ships, planes, trains, trucks or even cars is a more open question.
What do the different colors mean?
The hydrogen economy follows its own color theory. Only
green
hydrogen that is generated from water by electrolysis with the help of green electricity
is truly climate-neutral
. Currently,
gray
hydrogen
is used almost exclusively
, for the production of which natural gas is vaporized and thus CO2 is released.
The rest is mostly
blue
hydrogen, which is produced using the same method as gray, but without releasing CO2 into the atmosphere. Instead, it is saved. A special form is
turquoise
hydrogen: the methane pyrolysis process leaves solid carbon that can be reused as a raw material - but this has only happened on a small scale so far. The carbon footprint of these methods depends, among other things, on whether the heat is generated using renewable energy.
Hydrogen is
low in CO2, but not green but
red
or
purple
, if the electrolyser is operated with nuclear power. And as a variant of the gray, there is also
black
or
brown
Hydrogen, if coal is burned instead of natural gas.
While Japan initially wants to establish a gray hydrogen economy and later switch to green, the German and European hydrogen strategy are relying on a quick breakthrough for green technology - which means, among other things, that much more green electricity is needed than already.
The federal government therefore wants to promote the import of huge amounts of green hydrogen from sunny and windy countries.
What does this cost?
Green hydrogen is not price competitive today.
That could only change with mass use - or with CO2 prices clearly in the three-digit range.
And everything is missing for the conversion of the previous fossil processes: electrolysers, distribution networks, storage ... In order to realize the EU hydrogen strategy, Oliver Wyman considers investments of 350 billion euros to be necessary by 2030 alone - and that is only the impetus before the market really starts to move from 2040 onwards.
It will not work without government subsidies.
At the same time, however, a lucrative business is also emerging, especially for mechanical engineering.
Who's in the running?
Hydrogen is hot. Hardly any industrial or energy company takes the opportunity to adorn itself with H2. Some can still be highlighted. The industrial gas group Linde sees itself as the world market leader in several stages of the hydrogen business. On the site of the Total Leuna refinery in Saxony-Anhalt, Linde plans to open the world's largest electrolyser for green hydrogen with a capacity of 24 megawatts next year, and the Sultanate of Oman, with the help of various Asian companies, is increasing it with 25 megawatts. The city of Hamburg is aiming for as much as 100 megawatts at the site of the abandoned coal-fired power station Moorburg. The plant is to be built by Siemens Energy, which has teamed up with Linde's French competitor Air Liquide as a major hydrogen player.
The previous record holders with 10 megawatts each were set up by Toshiba in Fukushima, Japan, and Shell in the Rhineland refinery.
Like other oil and gas companies, Shell sees its future in the hydrogen business.
The steel company Thyssenkrupp not only depends on its fate for green steel production, it also sees hope in the company's own plant construction in the short term to ensure survival in a weak core business and at the same time gigantic future investments.
Thyssenkrupp, for example, has a contract for a 20-megawatt electrolyser for the Saudi Arabian art city Neom, where ex-RWE boss
Peter Terium
(57) is the energy director and wants to build a world center for hydrogen
exports
for five billion dollars.
Why is there a dispute about hydrogen?
That usually happens when it comes to mobility. Volkswagen CEO
Herbert Diess
(62), for example, reacts to the touch whenever fuel cells are brought into play as an alternative to battery-electric cars, in which his group invests tens of billions of euros. "The hydrogen car is proven NOT the climate solution" and "pure waste of time", he tweeted to Federal Transport Minister
Andreas Scheuer
(46, CSU) - who sees it very differently, in line with
Wolfgang Reitzle
(72). The Linde and Continental supervisory board chief sees the previous energy turnaround and fixation on electric cars as a wrong path. Reitzle and Diess were once in the management of BMW at the same time.
The hydrogen strategists hope for the broadest possible purchase. For the mega-investments in new plants to be worthwhile, ammonia and green steel would probably not be enough. At the same time, some of them hope that the technology could offer a way out to save industrial structures around the combustion engine with hundreds of thousands of jobs in Germany alone into the climate-neutral age. The proponents of electromobility, on the other hand, fear that this could slow down their success.
There are definitely fans of hydrogen in the green electricity industry because electrolysers also offer an option for storing German wind and solar power in times of surplus.
They then sometimes connect their systems to hydrogen filling stations for trucks, buses or cars - but are in conflict with the federal hydrogen
strategy
in other ways: Research
Minister Anja Karliczek
(50, CDU) describes it as "green, global and big" - not green, local and small.
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