Energy transition: who will supply Germany with green hydrogen?

"The energy transition will require large amounts of green hydrogen and fuels and chemicals made from it. A study shows where the energy source could come from.

Green hydrogen and products made from it such as ammonia, methanol and synthetic fuels are considered a central pillar of the energy transition. 

Estimates assume an energy requirement of up to 110 terawatt hours, which can be covered annually by the end of the decade using hydrogen as an energy source, when 80 percent of the energy system has been converted to renewables. This corresponds to about half of the current annual hydrogen consumption in Germany (1.7 million tons of hydrogen). By 2045, the amount could potentially quadruple.

Despite a massive expansion of photovoltaic and wind power plants, Germany will only be able to produce a certain proportion itself via electrolysis of water in order to meet the needs of the steel, chemical and glass industries and the transport sector (especially ship, heavy goods and air traffic) and the energy sector in gas power plants or as energy storage. 

But where should the lion's share of green hydrogen come from and on which transport routes? And when will it be available? Questions that "Energy Systems of the Future" (ESYS) - an initiative of the German Academy of Science and Technology, National Academy Leopoldina and Academy Union - dealt with in a current study.

Ukraine is also a possible export country

"We looked at the options for importing green hydrogen by 2030 and saw that each option has advantages and disadvantages," says Cyril Stephanos, head of the ESYS coordination office. 

Green hydrogen, produced in sunny Spain, for example, could be transported to Germany by pipeline in three to five years if the existing infrastructure is converted accordingly. New infrastructure would require a construction period of eight to ten years. In principle, the Ukraine could also be considered as an export country because there is a large network of natural gas pipelines there.

 

However, hydrogen gas can only be efficiently transported by pipeline up to a distance of 4000 kilometers. 

 

For more distant potential hydrogen suppliers such as Morocco, shipping is the only option. 

 

However, the gas has to be liquefied for this, which requires a corresponding system at the respective production site. According to the study, imported liquid hydrogen cannot be expected before 2030 because there are still no ships for transporting liquid hydrogen. 

"We will therefore not be able to import large quantities of green hydrogen and its derivatives as quickly as many in this country would like," admits Stephanos. The import costs for green hydrogen would range between seven and 17 cents per kilowatt hour, depending on the production conditions, distance from the exporting country and transport route, in line with the prices of fossil hydrogen produced via gas reforming.

Other methods still under development

 

Synthetic hydrocarbons could be obtained cleanly from green hydrogen and carbon dioxide in Saudi Arabia or South Africa using Fischer-Tropsch synthesis. 

 

The same applies to methanol, which is produced in Brazil, for example. The chemicals could be available from overseas in as little as a year or two if the CO₂ needed to produce them is captured from industrial waste gases, such as those from cement production. 

It will take longer if carbon dioxide is extracted directly from the air. Appropriate methods are still under development. Depending on the CO₂ price, green methanol would not be competitive with the simple alcohol obtained from natural gas, which is the starting material for many chemicals, until 2030. It will take longer for green fuels from overseas to pay off and replace petrol.

The quickest way could be green ammonia from Morocco. “We could immediately import the ammonia produced from green hydrogen and nitrogen to a certain extent because ports, plants and the corresponding infrastructure already exist in many places,” says Stephanos. Green ammonia could then replace the counterpart made from natural gas in Germany, which could quickly help reduce CO₂ emissions.

The study shows that the import quantities of green hydrogen required for 2030 could be achieved provided the right political and economic course is set now. This also includes the creation of regulations for hydrogen transport by pipeline and by ship and certification for hydrogen production. Stephanos says Germany and the exporting countries must meet as equal partners. The exporting countries should also benefit from trading in green hydrogen and participate in the added value. Environmental and labor standards must be observed, resource conflicts over land and water monitored and avoided. It must not just be about who can deliver the cheapest hydrogen quickly.”