H2 engine as an alternative to fuel cells
H2 engines burn hydrogen and work in a similar way to conventional combustion engines. The German Hydrogen Engine Alliance is committed to greater funding for this alternative, and there are good reasons for this. A review.
The idea sounds tempting: instead of investing in completely new vehicles with fuel cells or battery-electric drives, conventional diesel trucks could be converted to run on hydrogen. It would also be relatively easy to set up the series production of new commercial vehicles with so-called hydrogen combustion engines. This sounds like a pragmatic solution, especially for heavy-duty transport, that would make it easier to achieve climate targets.
More robust than fuel cells
But how realistic is this scenario and what technology is behind it? A hydrogen combustion engine or H2 engine is a modified combustion engine that burns hydrogen instead of diesel. Technically, the solution is closely related to classic combustion engines, which results in a number of advantages: manufacturers can fall back on existing combustion technology.
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This means that this CO2-neutral alternative is quickly available and inexpensive to develop. In addition, hydrogen combustion engines are considered to be very robust. They are less sensitive to impurities in the hydrogen than fuel cells. Meanwhile, the achievable range is on a par with diesel engines. In addition, refueling stops can be completed in just a few minutes without any problems. Another important argument is the lower dependence on critical raw materials such as rare earths.
However, the hydrogen engine also has disadvantages compared to battery electric drives (BEV – Battery Electric Vehicles) and fuel cell electric vehicles (FCEV). These include its significantly lower efficiency. Only 30 to 40 percent of the energy is actually converted into drive energy in the H2 engine. Compared to a fuel cell with the same output, this results in higher consumption. In addition, nitrogen monoxide (NOx) is produced when hydrogen is burned, similar to natural gas vehicles. This not being completely emission-free could lead to tax disadvantages in some countries in future regulations.
300 billion euros for a clean transportation sector
Overall, however, the H2 engine is a serious alternative that should play a role in future investment decisions. Hydrogen propulsion via H2 engines and FCEVs is supported by the “REPowerEU strategy”. The 300 billion euro plan of the European Union aims to free Europe from fossil fuel supplies as quickly as possible and to reduce CO2 emissions in the transport sector. The plan is to reduce CO2 emissions in the transport sector by 45 percent across Europe by 2030.
The Hydrogen Engine Alliance, founded in January 2022, is also committed to the hydrogen engine, combining the knowledge of almost 50 renowned members from industry and research. As part of a special show by the Hydrogen Engine Alliance, visitors to this year's NUFAM (September 25–28) in Karlsruhe can get comprehensive information on the topic over two days.
The Hydrogen Engine Alliance sees hydrogen as an indispensable factor for a decisive reduction in CO2 in Europe. The association's experts are convinced that sufficient hydrogen is available for long-distance transport and that there will be no “competition with other uses” here. The background to this is figures from the EU and the automobile association ACEA, according to which hydrogen does not represent a limiting factor for commercial vehicle applications.
“Five percent of the green hydrogen available by 2030 is enough to refuel 100,000 commercial vehicles,” says Andreas Kufferath of the Hydrogen Engine Alliance. At the same time, he urges politicians to quickly define the regulatory framework. After all, Europe is not alone in pursuing this technology. In India, the first heavy-duty commercial vehicle with a hydrogen engine will hit the road as early as 2026.