Hydrogen

Definition

Hydrogen is a colourless and odourless gas at ambient temperatures. It is 14 times lighter than air and can be stored in a gaseous or liquefied form in special containers or in salt caverns underground. Hydrogen has the highest weight-related energy density of all secondary energy sources. The combustion of hydrogen releases large amounts of energy that can be converted back into electricity in fuel cells or used in combustion plants as heat for high-temperature processes. Hydrogen is produced using the following processes: electrolysis, pyrolysis and steam reforming. Electrolysis involves splitting water into hydrogen and oxygen using electrical energy. If renewable electricity is used for this purpose, this is known as green hydrogen. During pyrolysis, also known as methane cracking, methane is thermally broken down into hydrogen and solid carbon in the absence of oxygen. The use of renewable methane leads to negative CO₂ emissions. By far the largest proportion of hydrogen used today is produced by steam reforming: Hydrocarbons from fossil sources such as natural gas or renewable sources such as biogas are converted into hydrogen and carbon dioxide in a thermal reaction with the addition of steam. If the resulting carbon dioxide is then stored using carbon capture and storage technologies (see negative emissions technologies), the process can be implemented with low emissions.  

Current applications and opportunities 

In industry, hydrogen has long been used on a large scale in the manufacture of artificial fertilisers and explosives as well as in the food industry. However, this results in high carbon emissions. The switch to green hydrogen opens up new opportunities for decarbonisation at various points in the value chain. For energy use, green hydrogen can be converted back into electricity via fuel cells without emissions and used as a low-carbon fuel for heavy goods vehicles. Since 2020, the Hydrospider consortium of companies has been implementing a decarbonisation concept for heavy-duty transport in Switzerland, operating production facilities and a network of filling stations for green hydrogen. Nearly two dozen well-known transport and retail companies now use their own fleet of hydrogen lorries for the local distribution of goods.  

Individual synfuels are also on the verge of entering the market. Hydrogen is used to produce synthetic energy sources such as methane, methanol or synthetic fuels. This opens up promising potential for sustainable mobility in applications that are difficult to electrify, such as long-distance freight transport, shipping and aviation, but also for use in industrial high-temperature processes or for the provision of electricity during the winter months. 

Significantly expanded production capacity for green hydrogen in Switzerland could also promote the expansion of photovoltaic systems, as this would allow the surplus solar power generated in summer to be stored and meet increased demand for renewable energy. 

Industry and academic researchers are working closely together to develop new hydrogen technologies, for example in the reFuel.ch consortium, which is developing robust approaches to supplying Switzerland with sustainable fuels and basic chemicals. A total of 76 hydrogen projects are currently underway in Switzerland, primarily based at Empa, PSI, the two ETHs and research institutes at various universities of applied sciences and other universities. 

Challenges 

The role played by sustainably produced hydrogen in the entire value chain is as yet (too) small. It is almost exclusively produced in refineries by means of steam reformation of natural gas. However, this process is very carbon-intensive. Low-carbon production processes currently account for only about one percent of hydrogen production. In general, the investments required for the production, storage and transport of sustainable hydrogen are extremely high. Depending on fluctuations in the energy market, the price for producing 1 kilogram of green hydrogen in Switzerland is currently around 7 euros per kilogram, which is more than twice as high as the market price for conventionally produced hydrogen. 

There are now four plants in operation in Switzerland that produce hydrogen from renewable energy by means of electrolysis. Three of them use hydropower as an energy source (Schiffenen in Fribourg, Gösgen in Solothurn and Kubel in St. Gallen), while the fourth (Dietikon in Zurich) uses waste heat from a waste incineration plant. Since electrolysis requires a lot of electrical energy and renewable electricity will not be available in sufficient quantities all year round in the foreseeable future, hydrogen will have to be imported on a large scale from regions where solar energy can be produced more cheaply and with less seasonal fluctuation, such as the Earth’s sun belt. However, transport, storage and distribution to applications also pose major challenges for the provision of sustainable hydrogen. 

The possibility of connecting Switzerland to the European Hydrogen Backbone, an association of 33 gas network operators aiming to establish a Europe-wide hydrogen transport network, should therefore be examined. In addition, an import strategy should be pursued with countries in the Earth’s sun belt. Regulatory and policy gaps must be closed and technical barriers addressed in order to improve planning certainty for investing companies. Science and industry should work closely together to invest in further pilot and demonstration plants in order to bring innovative projects in all areas of the value chain to market maturity. 

Focus on industry

The future holds great potential for the manufacture of production, transport and storage facilities for sustainable hydrogen and hydrogen derivatives. In Switzerland, the main focus is on developing electrolysis capacities and scaling up technologies for the production of synfuels and basic chemicals as feedstocks for other products.  

The hydrogen industry tends to be a highly automated sector. The shortage of specialists therefore plays a less important role. Companies and universities now offer various courses and training programmes that equip engineers and planners with the expertise they need to plan and operate hydrogen technologies. Key to this are the safety aspects of handling hydrogen and knowledge of processes in pressure vessels.  

International perspective

By international standards, Switzerland has led the way primarily with its pioneering work in the field of mobility. When it comes to using hydrogen as an emission-free energy source for high-temperature processes, countries such as Belgium, Germany, the Netherlands and Sweden are further ahead owing to their industrial focus and the resulting improved market conditions for decarbonisation projects. However, in the area of research and development of innovative projects and niche products, numerous local research groups work closely with European partners, for example in Horizon Europe projects as well as in collaborative ventures such as the EU project MetroHyVe, which is driving forward the development and standardisation of measurement techniques in the hydrogen sector. 

Future applications

According to the Swiss Energy Strategy 2050, the demand for hydrogen and its derivative products will increase to 10 to 20 percent of final energy consumption, depending on the scenario. In addition to direct energy applications for mobility, the focus is on the storage capacity of hydrogen. The surplus solar energy available in summer would be bound in hydrogen or hydrogen derivatives, stored and made available again in winter as required, which could make an important contribution to stabilising the entire electricity system. 

In the future, sustainable hydrogen will be increasingly used in industry as an emission-free fuel for high-temperature process heat, which is the third-largest consumer group after mobility and space heating. In addition, hydrogen could become important in the cement, steel, glass, ceramics and chemical industries as well as in the processing industry or in refineries as a starting point for the production of base chemicals for various materials such as polymers. 

Thanks to its beneficial properties, hydrogen has enormous untapped potential as an energy source and chemical feedstock for decarbonisation in a wide range of sectors. Whether this succeeds also depends on trends in demand and pricing in the energy market and the political landscape.