Hydrogen, but why?
When it comes to meeting our energy demands, fossil fuels have their days numbered. Fossil fuels are finite and, literally, running out. That alone is a good motivation to start thinking about alternatives. Another significant reason is the urgent need for decarbonisation and a sustainable transition, to avoid the emission of greenhouse gases such as CO₂.
Renewable energies hold the solution. Well, not entirely. One of the major issues is intermittency, particularly when it comes to solar and wind energy. This means we need a way to store the extra energy produced, which we can count on when the Sun isn’t shining, and wind isn’t blowing. Batteries can handle part of this ‘energy storage’ job, but not in every case. And that’s precisely where hydrogen comes into play.
Hydrogen serves as a clean energy storage solution —often also called a clean energy vector. It has the potential to decarbonise transport, industry, building heating, power… Plus it also serves as a feedstock, for example, combined with captured carbon to produce carbon-based liquid fuels and ammonia for fertilisers. And hydrogen isn’t just a future idea, hydrogen is already used as a significant solution.
Refining
Nowadays, the largest share of hydrogen demand comes from fossil fuel refineries. According to data from the latest Clean Hydrogen Monitor report, in 2023 refining accounted for 58% of the total demand in Europe. Big oil relies on refining processes, particularly hydrotreating and hydrocracking, which require hydrogen to convert crude oil into ubiquitous products such as petrol and diesel.
Hydrocracking is by far the most common hydrogen hungry process. It consists of the chemical breakdown of heavy, long-chain hydrocarbons into lighter ones under high temperature and pressure. The objective is to achieve more valuable products, increasing the yield towards gasoline and jet fuel. Hydrotreating, on the other hand, involves the removal of impurities like sulphur compounds, nitrogen, and metals from hydrocarbon streams to make them cleaner and more efficient.
Although hungry for hydrogen, refineries remain also a big producer of this gas, a subproduct at various stages of crude processing. While simpler configurations are sometimes self-sufficient, producing enough hydrogen to operate with catalytic reforming, bigger refineries with extensive hydrotreating or hydrocracking processes require an additional hydrogen feedstock. As hydrogen is not yet a global commodity and is rarely transported over long distances, it is typically produced on-site.
Currently, most hydrogen used in refineries is generated via a process known as steam methane reforming (SMR) —commonly called grey hydrogen—, which needs natural gas as starting material. SMR has however very high CO₂ emissions – in fact it generates over ten times more carbon dioxide than hydrogen in weight. Luckily, Europe is working and investing in innovation, towards green hydrogen production.
There are around 68 announced clean hydrogen projects across the continent scheduled for development by 2030. Major projects include Holland Hydrogen I at Shell’s Rotterdam refinery in the Netherlands, the Normand’Hy project in France, and Galp’s development in Sines, Portugal.
Ammonia, methanol and other chemicals
Hydrogen is also indispensable in the production of chemicals. The ammonia industry is, next to refineries, the second largest hydrogen consuming sector in the EU, accounting for 25% of total demand. Ammonia is primarily used in the synthesis of fertilisers and also plays a role in the production of synthetic fabrics, plastics or explosives. However, there is a growing interest in another potential application: ammonia as an alternative energy (and hydrogen) carrier.
The practical storage and transport of hydrogen present significant challenges. Hydrogen is the lightest element, which means it easily escapes even the most airtight vessels. Plus, it sometimes reacts with unprotected metals, creating embrittlement and degradation. Additionally, the storage and transport of compressed and liquefied hydrogen could carry a significant risk of combustion and explosion if exposed to oxygen, posing a serious safety concern.
Ammonia can lend a hand here. Through the Haber–Bosch process, hydrogen is combined with nitrogen to produce ammonia, which is stored and transported more easily and safely. When needed, hydrogen is reversibly re-extracted by ‘breaking’ ammonia using high temperatures or electrochemical methods, among other solutions.
Other chemicals that require hydrogen in their production include methanol, cyclohexane, hydrogen peroxide, and many more! Methanol is an important raw material in the chemical sector, used in the manufacture of adhesives, solvents, and paints. Cyclohexane is a precursor of nylon, while hydrogen peroxide plays a crucial role in the production of detergents, as well as for water purification, bleaching paper, pulp, and textiles.
As with refineries, large-scale hydrogen production is mostly concentrated in industrial areas near chemical producers. Many of these industrial clusters are located close to ports, which would facilitate future trade of hydrogen and its derivatives.
Other industries
Hydrogen is also used in industries beyond the chemical sector. In steel manufacturing and metals processing, mixtures of hydrogen and nitrogen are commonly used as an inert protective atmosphere in conventional batch annealing furnaces —a heat treatment process that makes materials more workable. Batch annealing with 100% hydrogen is also possible, though. This second method results in better productivity, improved mechanical properties, surface, and product quality.
In the glass industry, hydrogen serves as an inerting or protective gas during flat glass production. It also plays a role in the flame polishing of glass products.
We can even find hydrogen applications in food processing! Here, it’s particularly important in the production of margarine. Through hydrogenation, unsaturated fatty acids in vegetable oils are converted into saturated fats. This process involves dispersing hydrogen gas in the oil in the presence of a nickel catalyst, producing a more stable, solid fat suitable for food products.
Building heating
Hydrogen is increasingly being explored as a clean alternative, in the case of green hydrogen, for both industrial and home heating.
In industry, hydrogen is mainly used for generating high-temperature heat. It’s burned in boilers to produce steam or used in combined heat and power systems, often on-site. In many cases, this hydrogen isn’t produced intentionally, but is a by-product of other processes, such as the chlor-alkali reaction, used in the production of chlorine and soda. However, instead of going to waste, it’s reused to generate both heat and electricity.
In domestic heating, hydrogen is being tested as an additive (and, eventually, a potential replacement) for natural gas in household boilers. Across Europe, different trials are testing how hydrogen blends could safely power existing heating systems. The idea is to cut emissions without needing to rip out or replace existing infrastructure. However, some critics argue that heating homes with green hydrogen is inefficient, as a lot of energy is lost at each stage of the process. So, will hydrogen heat our homes in future? Possibly, but only if challenges like cost, efficiency and infrastructure are tackled head-on.
Transport
Hydrogen is fuelled in a very similar way to petrol and diesel, which is much faster than charging electric vehicles, especially larger ones. Refuelling a hydrogen car from a pump tends to take less than five minutes. Moreover, it also outcompetes with the infrastructure required. Hydrogen is easily and safely stored on-site and delivered with lower energy and cost requirements compared to a fast-charging electric station.
Hydrogen refuelling stations are exponential growing in Europe. According to data from the European Hydrogen Observatory , the continent scaled from just one station in 2003 to almost 200 stations today, most of them in Germany. Outside Europe, China is leading the way, followed by South Korea, Japan and the United States.
This growth also means an increase in vehicles powered by hydrogen, with examples in both private and community transport. Currently, these are fuel cell electric vehicles (FCEVs), similar to electric vehicles, but instead of getting energy from a battery, FCEVs generate electricity through an electrochemical reaction between hydrogen and oxygen in a fuel cell stack — which is sort of an electrolyser in reverse.
An example here is the Toyota Mirai model, launched in 2014 and claimed as the world’s first production hydrogen powered car. With a price tag of nearly €75,000, however, it’s not within everyone’s budget. Another model is the Hyundai NEXO, whose second generation was unveiled in April this year. It’s available in selected markets only and only with certain versions or models. Bigger options, such as hydrogen trucks, are also a reality, with models from major automotive companies such as Volvo, BMW and DAF.
Regarding community transport, we already see many hydrogen buses running in numerous European cities. Places like Barcelona, Oslo and Milan have integrated them into the public transport system just like regular buses, demonstrating feasibility and scalability.
Some regions have even gone further, literally, using hydrogen in long distance transport solutions, such as trains. In Germany, the French company Alstom, introduced the world’s first passenger train powered by a hydrogen fuel cell in 2018. These trains operated until last year, when the German rail operator RMV announced a return to diesel trains until the end of 2025 due to component reliability issues.
And what about travel by water? Norway’s longest ferry route will soon have two new vessels powered by locally produced green hydrogen. Outside Europe, San Francisco had the world’s first hydrogen-powered commercial passenger ferry, a six-month operational pilot during 2024.
One thing is clear: the hydrogen era has already begun. Hydrogen is both a present reality and a key part of our future in the journey towards decarbonisation. It offers a flexible and scalable solution to some of the greatest challenges in energy, transport, and industry. That’s why its use is expanding into new applications and growing within existing ones. The greatest challenge now is to commit to green hydrogen in order to ensure an effective and truly sustainable transition.