a central solution to the climate crisis to emotionally heated detailed
discussions on the possible use of hydrogen as a fuel for a wide variety of means of transport, from cars and trucks to ships, railways and aircrafts.
The different perspectives, from the all-encompassing energy carrier to the question of whether one‘s own car should soon have a hydrogen drive, also have an effect on the valuations of the shares of companies with hydrogen technologies. Companies like Nel ASA, Ballard Power, Plug Power & Co are on everyone‘s lips, so to speak. The opinions on them also range from strict rejection to „absolutely buy“.
Yet, hydrogen has been used in industries for a long time already.
In addition to the „mundane“ use of hydrogen to produce nitrogen fertiliser, synthetic fuels or to crack crude oil in refineries, hydrogen has been used as
a fuel in space travel since the 1960s, which would not even be possible without it. Derived from this, hydrogen is being investigated and
in some cases already used as a possible energy source for aviation, for the automotive industry, for power plants, for heating purposes and much more.
On the one hand, hydrogen is to be used wherever high-temperature processes have so far only been technologically feasible through the use of carbon-containing energy sources such as natural gas, crude oil or coal, whereby enormous amounts of CO2 are released. It is assumed, for example, that in steel production 95% of the CO2 emissions can be avoided through the use of hydrogen compared to conventional methods.
On the other hand, hydrogen is considered a potent energy storage medium for powering all kinds of vehicles, as it is relatively easy to store and transport. In the field of transport technology, hydrogen is a direct competitor of stored electrical energy and there are real „religious wars“ about whether the mobility of the future can rather be guaranteed by hydrogen drives or accumulators
and electric motors.
What are the fundamental arguments for or against the use of hydrogen as an energy source?
Against: Hydrogen is an explosive gas and there are no natural hydrogen deposits. Hydrogen must be produced in processes with a high energy demand. If this is not done „just in time“ and at the desired place of consumption, it has to be transported and stored.
For: Hydrogen can be burnt almost residue-free. It can also be converted into electricity by electrochemical processes at the point of consumption without leaving any residues.
However, the respective hydrogen production process – and there are quite a few of them – plays a decisive role in assessing whether the use of hydrogen makes sense. Basically, only „green“ hydrogen is „good“ hydrogen. When people talk about „green hydrogen“, they are really only implying that
this hydrogen is CO2-free, usually obtained by using renewable energies – in the best case unused energy, e. g. from electricity generation by wind
or solar power. Water is split into hydrogen and oxygen by electrolysis. The whole process is complex and cost-intensive.
Therefore, newer processes, which are still being tested, rely on the fermentation of biomass and the production of hydrogen from green algae, for example, for cost and efficiency reasons. These technologies are said to have enormous development potential.
The German government wants to support this process with the national hydrogen strategy, a 300 million euro funding programme. Its objectives are as follows: Green hydrogen is the petroleum of tomorrow. The flexible energy carrier is indispensable for the energy transition and opens up new markets for us. With the National Hydrogen Strategy, we are making Germany a global pioneer.
The EU community of states is also currently addressing these problems and has opened a discussion under the heading „Hydrogen – Key to More Climate Protection in Europe“ in the background of the EU‘s climate goals.
One of the central problems of the hydrogen economy is the relatively low efficiency of producing green hydrogen from electricity. As long as electricity is scarce and production and consumption are synchronised, its direct transport has clear advantages over the diversions via hydrogen.
However, this is changing at a rapid pace because renewable energy sources such as sun and wind do not always occur when they are needed. Until now, the storage of excess electricity has been a task of pumped-storage power plants, which are increasingly being supplemented by accumulators.
However, these are expensive and also have losses. This is where hydrogen technology comes into its own. Electricity can be converted into hydrogen directly at the point of generation, e.g. in offshore wind farms, which is then transported to the consumers via pipelines. Since the transport of pure hydrogen in pipelines makes high technical demands, an alternative currently being tested is the conversion of hydrogen plus carbon dioxide into methane, which is then suitable for normal natural gas pipelines and natural gas storage facilities. (Power to Gas).
Whether one then uses the hydrogen itself as an energy source and burns it, generates electricity from hydrogen
in fuel cells, or burns it as methane depends on the purpose of use as well as the efficiencies to be achieved. How differently this is viewed by industry can be seen from the fact that VW,
for example, sees no future for hydrogen-powered cars, but BMW is researching this topic with already existing test models.