Small but mighty
Hydrogen (H) is the smallest and lightest known chemical element, making it number one on the periodic table. It is a colourless, odourless, and highly flammable gas at room temperature. The liquid point is at -253 degrees Celsius. Due to its small size, hydrogen can enter and exit almost everywhere. Even plastic is no obstacle. An effective barrier can only be created using special metals. It is also by far the most common element in our universe. However, this is not the case for the earth, where hydrogen is predominantly found in bound form. Water (consisting of hydrogen and oxygen - H2O) is the best known and most common compound. In the air, hydrogen occurs mainly as water vapour. As the name already suggests, hydrogen is also part of the hydrocarbon compounds such as natural gas or petroleum.
Hydrogen is ecologically very beneficial. Its "combustion" via fuel cells does not produce any greenhouse gases or other undesirable by-products such as fine dust. It only produces energy and water. Hydrogen has the potential to become a climate-neutral fuel that is harmless to health.
However, note that hydrogen is only an energy carrier and not an actual energy resource like oil, natural gas or coal. In other words, there are no pure hydrogen deposits that we could develop and use. Therefore, hydrogen must first be artificially produced and then stored in large quantities before it can be used.
Not all hydrogen is the same - it is grey, blue or green
Hydrogen can be produced by various methods, with the two methods of steam reforming from fossil fuels and water electrolysis using electrical energy being primarily relevant in today’s industry. As these methods suggest, the "cleanliness" of hydrogen depends on how it is produced. There are primarily three different types:
- Grey hydrogen is produced from fossil fuels (primarily natural gas), generating between 5 and 25 tons of CO2 per ton of hydrogen as a by-product.
- Blue hydrogen is also produced from fossil fuels, whereby the CO2 is captured and stored (Carbon Capture and Storage, CCS). This method and its economic viability depends crucially on the development of CCS technology
- Green hydrogen is produced from water by electrolysis. Electricity is used from renewable energies such as solar or wind power. No harmful CO2 is produced as a by-product, just oxygen.
Since there is a consensus that carbon capture and storage will be needed more urgently in other areas in the future and there are still many unanswered questions about this technology, green hydrogen is considered the most sustainable option. It is the focus of politics and business.
Hydrogen versus electrification: the big competition?
Hydrogen releases energy very cleanly, but it brings other challenges. This concerns in particular storage and transport due to the very small size of the molecules, the low liquid point, the high flammability and the reactivity with oxygen (remember the oxyhydrogen experiment in chemistry class).
Although there are already hydrogen cars and even bicycles, experts assume that hydrogen will prevail in areas beyond electrification. Where batteries are too heavy or high heat is needed, it represents an exciting alternative. In concrete terms, this means that hydrogen is considered a promising technology in four areas:
Heavy transport, energy storage, heat-intensive industrial processes such as steel production and as an addition or even replacement of natural gas as a heating medium. It is equally important to understand that hydrogen solutions in mobility are always related to electrification, as a hydrogen drive also requires an electric motor and a battery.
On the way to a low-carbon society, hydrogen and electrification are less of a competitor rather than complementary partners.
Costs, costs and more costs
Last but not least, it is crucial for new technologies whether and when they are economically competitive with the competing conventional technologies. At the peak of the gas prices in recent years (October 2021), green hydrogen already reached price parity with grey hydrogen. Regardless of the volatility of the gas price, a more profound and longer-term development was observed, which shows a lower cost of green hydrogen on the one hand and increased capacity and market adoption on the other:
- The costs of renewable energy and electrolysis have fallen sharply and continue to do so. Therefore, the cost of green hydrogen has fallen by 50% in the past five years. It is expected to fall another 60-90% by 2030. On the other hand, prices for fossil fuels are expected to rise in the longer term.
- There are technological developments in electrolysers and fuel cells that further increase their efficiency and thus increase the attractiveness of the technology.
- In recent months, various countries around the world, including the EU, have recognized hydrogen as an important component of their decarbonization strategies and have passed far-reaching draft laws and funding programs. Countries that generate around 70% of global economic output measured in terms of GDP, have now defined a hydrogen strategy. The EU and China are ascribed pioneering roles here.
- A clear dynamic is also emerging in the private sector. Parallel to the political funding programs, several companies have announced large hydrogen projects. For example, the “Green Hydrogen Catapult” consortium plans to produce 25 gigawatts of green hydrogen from 2026. This corresponds to fifty times the current global production and requires an investment of over USD 110 billion.
In addition to the climate, the manufacturers of hydrogen technologies, their suppliers and the producers of renewable energies should benefit from this positive development too.
The signs are good that hydrogen technology can make a significant contribution to solving climate change. The stronger the political support and the higher the investments, the faster the energy transition will take place. However, (green) hydrogen should not be hyped up as the sole silver bullet against climate change. It must always be seen in combination with other approaches and technologies for reducing greenhouse gases, such as electrification.