Hydrogen and fuel cells for cars – Auto & Mobil

The vision is half a century old, it comes from the oil crises of the 1970s: The Middle East as a center of global oil production would also be an ideal region for non-fossil fuels. With enough sun to produce photovoltaic electricity for now barely more than a cent per kilowatt hour. The sun enters the tank with hydrogen. This universal fuel can also be produced cheaply by hydropower in Canada or by wind energy in Patagonia, on the stormy southern tip of South America. It would be the energetic declaration of independence from the fossil fuel age and the climate crisis caused by it.

However, not much has happened in the past 50 years. At least not with individual hydrogen mobility. Mercedes announced a B-Class with fuel cell drive in 2004 – proof that the drive technology fits into a compact car. But after a small series (later also with the EQC F-Cell), the entire know-how was outsourced to the truck division Daimler Trucks. Toyota did better with the Mirai fuel cell car and Hyundai with the Nexo. Both models are now in the second generation and in larger numbers. In China, too, there are already over ten thousand fuel cell vehicles on the road, especially buses and trucks.

Hydrogen is a key element in solving the climate crisis, not just in Asia

The hydrogen future is foreseeable in Asia. The technology becomes cheaper with higher quantities, the first Chinese automobile manufacturers bring their own fuel cell cars onto the market and the governments (also in Japan and Korea) are promoting the development of the corresponding refueling infrastructure. In this country there can be no talk of such a spirit of optimism. But why is Asia behaving so differently?

Hydrogen is a key element in solving the climate crisis, not just in Asia. In the meantime, more than 35 countries have drawn up a national hydrogen strategy. Even China, Russia and Saudi Arabia want to be climate neutral by 2060; Australia, as one of the largest emitters of CO2, has set itself this target by 2050. Germany wants to be ready by 2045, but the transport sector remains one of the biggest hurdles. Since 1990, cars and trucks, diesel trains, airplanes and ships have been emitting around 160 million tons of CO2 per year in this country at a relatively constant rate. Despite all the new electric vehicles, a consistent turnaround in traffic is a long time coming.

Hydrogen can accelerate this process. Governments around the world have made around 100 billion euros available for the next few years to build a new energy path – from hydrogen generation and transport to distribution. This sum is currently being tripled by investments from the industrial, heating and transport sectors. If you add in the latest announcements, the sums at stake are even larger.

A global hydrogen economy for the generation and transport of the green energy carrier is developing at breakneck speed. A solar and wind park with four gigawatts (GW) capacity is currently being built in Saudi Arabia in the north-west (NEOM), and electrolysers with a total output of 2.2 GW are to be built for this purpose. Part of the hydrogen generated in this way will then be synthesized into ammonia with nitrogen from the air and shipped to Rotterdam from 2025. Australia is also currently developing several solar and wind parks with an output of up to ten GW. The hydrogen produced there is to be liquefied (at minus 253 degrees Celsius), and the production of liquid methanol or ammonia for ship transport is also planned. Transport via pipelines directly from the European neighborhood is even simpler and more energy-efficient and cost-efficient. The European Hydrogen Backbone, an initiative of gas network operators, expects that almost 40,000 kilometers of hydrogen pipelines will be built in Europe by 2040. Parts of the natural gas network can also be used for this purpose through reallocation.

But how useful are fuel cell cars? In urban mobility with small vehicles, short journeys and many charging points, battery-only vehicles will dominate. But what about regions in which green electricity is only available to a limited extent and grid expansion is stalling? And what do drivers who want to combine long ranges and fast refueling times do? Fuel cell vehicles are a useful addition here, and the corresponding infrastructure can also be financed.

The bottom line is that there is a tie. From solar / wind generation to the drive wheel, battery and fuel cell vehicles have comparable energy efficiencies. The total emissions over the life cycle (including vehicle production through to the charging and refueling infrastructure) are similar for both types of drive. In regions with limited expansion potential for renewable energies, including Germany, hydrogen-based drive systems have great advantages, as they can participate in the emerging world market for green hydrogen and can also store it on a large scale and for long periods in salt caverns or locally in pipe fields.

If the transport sector in Germany is to reduce its CO2 emissions by half by 2030, this can only be achieved through the use of all climate-neutral drive technologies. Because mileage, especially in private transport, will not decrease in the future; individual mobility remains a basic need for most people.

The author heads the Hydrogen Technologies division at the Fraunhofer Institute for Solar Energy Systems and holds an honorary professorship at the University of Cape Town. He is also co-speaker of the hydrogen network with 35 Fraunhofer institutes and is vice president of the German Hydrogen and Fuel Cell Association.

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