When the Olympic flame is lit on July 23 in the National Stadium in Tokyo, a small revolution will take place. Because what will be burnt is not conventional propane gas (as is usually the case), but hydrogen. Apart from a small quantity of nitrogen oxide, it will produce only water vapor and no CO2 emissions. The Olympic organizers are relying heavily on the versatile element; the aim is for Tokyo to go down in history as the first Olympic Games of the hydrogen age. This is why 500 hydrogen-powered Toyota Mirai cars will transport the athletes to the competitions and fuel cells will supply the electricity for the Olympic village. The Japanese have often been early adopters of new technologies. For the last Tokyo Olympics in 1964 they introduced the Shinkansen high-speed train, which remains a benchmark for modern rail technology even today. Will the global sporting festival represent the start of the hydrogen era?
There is no lack of ambitious plans concerning the tiny molecule. At the end of May the German federal government announced its support for 62 new hydrogen projects. Investments of more than eight billion euros will fund investigations into how the element can be produced, transported, and used in an industrial setting. “We will make Germany into the hydrogen nation,” said transport minister Andreas Scheuer when the plans were presented.
Announcements of this kind have been made relatively often, for example, on January 12, 1999, when the first hydrogen fuel station in Europe was opened in Hamburg. But very little has happened during the intervening two decades. There are now just 91 H2 fuel stations in Germany – a very small number compared with the 14,000 or so conventional gas stations. And only a few thousand hydrogen cars have been produced around the world. Why should the hydrogen revolution really be starting now?
No climate neutrality without hydrogen
Because it has to, according to the experts. “We can’t become climate-neutral by 2045 without hydrogen,” says Roland Dittmeyer, professor at the Karlsruhe Institute of Technology (KIT). The specialists in the field argue that to stop climate change, the world needs to phase out the use of fossil fuels and raw materials quickly and the obvious replacement for them is the most common element in the universe. Hydrogen can be produced using green electricity. It can supply electricity and heat from fuel cells, be converted into synthetic fuels and replace both oil and coal in industry. “Hydrogen is a genuine all-rounder,” explains Eric Heymann from Deutsche Bank Research in Frankfurt, the bank’s think tank. But then he adds one small phrase: “in theory.” Because in practice there are still a lot of unanswered questions.
One thing that is uncertain, for example, is where the hydrogen will come from. If we are to make our economy more climate-friendly with the help of hydrogen, it will need to be the green form of the gas (see the box). Only electricity from renewable sources can be used to produce it and that is in short supply. “The hydrogen producers will be competing for the electricity with electric cars, data centers, and heat pumps. And the prospect of permanent surpluses from renewable sources is still a long way off,” emphasizes Heymann. He does not believe that this situation will change over the decades to come. “Germany will remain a hydrogen-importing country.”
The German research organization Forschungszentrum Jülich has run complex simulations to calculate how much hydrogen we will need in the future. The results show that if CO2 emissions are to be reduced by 95 percent, Germany will require twelve million metric tons of hydrogen per year by the middle of the century. In the lowest-cost scenario, 45 percent of our requirements would come from domestic production and the rest would be imported. In theory, this is possible. According to a calculation by the Fraunhofer Institute for Energy Economics and Energy System Technology IEE, by 2050 enough green electricity will be generated to manufacture almost two billion metric tons of liquid hydrogen. The requirement of twelve million metric tons calculated by the researchers at the Forschungszentrum Jülich could therefore easily be met. However, all of this is hypothetical because none of the necessary production facilities are yet in existence.
Imports of 55 percent of hydrogen by 2050
Hydrogen in the natural gas network
And then there is the question of transport. Professor Detlef Stolten from the Forschungszentrum Jülich believes that hydrogen will be imported in liquid form in the future, for example in tanker ships. “The existing natural gas pipelines could be used to distribute the hydrogen within the country. The network lends itself to this.” The energy expert is proposing that some of the pipelines in the natural gas network could be completely converted to hydrogen use. He believes that mixed distribution together with natural gas would only make sense on a local scale.
Hydrogen is a difficult substance to transport. To liquefy the gas, it has to be cooled to minus 253 degrees Celsius. It also attacks many metals, causing cracks and even breaks (this is known as hydrogen embrittlement). Some experts are therefore suggesting that H2 should be converted into more easily managed substances for transport purposes. “Practical solutions include methane, methanol, and ammonia,” says Dittmeyer. For example, methane can be synthesized from water and carbon dioxide and because methane is the main component of natural gas, it can be distributed via the existing networks.
More futuristic transport concepts are also under consideration. One idea is to combine the hydrogen network with the electricity grid. Special power lines could be installed inside the pipelines with the liquid H2. At an ambient temperature of minus 253 degrees, the power lines would lose their resistance (and become superconductors) which would allow the electricity to be transported almost without losses.
However, it is uncertain how much hydrogen will ultimately be needed, because the usage scenarios are constantly changing. In the field of transport, for example, hydrogen is likely to play a less important role than originally envisaged. The fuel cell car, which was supposed to represent the future of mobility, is currently facing serious competition from battery-powered models. “It is becoming less and less likely every day that hydrogen will be used in cars,” confirms Heymann. Fuel cell cars are being held back by their poor energy footprint. Firstly, the hydrogen has to be produced at great effort and then it has to be converted back into electricity in the fuel cell. As a result, between two and three times as much electricity is needed per kilometer as for battery-powered transport.
No market for hydrogen trucks?
The prospects are not looking good for hydrogen trucks either. Until now, the rule of thumb has been that the electricity needs to be supplied by fuel cells for a range of 600 kilometers or more, because the batteries would be too heavy. However, the energy density of batteries is constantly increasing, which shifts the balance in favor of battery trucks. In 2017, every kilo of battery supplied 150 watt hours. Now more than 200 are possible and in the future the figure will reach 400. The Dutch transport researcher Auke Hoekstra believes that in five years’ time there will be battery-powered 40-ton trucks on the roads that can cover a distance of 800 kilometers. They could take over around 80 percent of all journeys and not much would be left for the H2 trucks to do.
By contrast, hydrogen is certain to take off in the aviation industry. The aircraft of tomorrow will probably be burning e-fuels, which are climate-neutral synthetic fuels produced using electricity, in their jet engines. The Karlsruhe Institute of Technology already has a system that manufactures fuels in this way by filtering carbon dioxide out of the air and combining it with hydrogen from water. As electricity from renewable sources is used for all the processes, the result is a climate-neutral fuel. The carbon dioxide in the exhaust gases has already been extracted from the atmosphere, making this in principle a zero-sum game. In addition, the aircraft jet engines could run on e-fuels without the need for conversion.
A huge effort is required
However, an enormous amount of work is involved in all these green innovations. Electrolyzers have to be built, pipelines repurposed, and industrial plants and processes converted to new fuels. These things will not happen overnight. Refineries, steel plants, and heating systems are designed for a useful life of 25 years or more and so in these areas it is not possible simply to take a new technical direction. In addition, green hydrogen will continue to be in short supply for a long time to come. In order to stay even partly on schedule, we will need to abandon our green principles temporarily. “We could start right away, but using turquoise or blue hydrogen,” explains Roland Dittmeyer. But Detlef Stolten from the Forschungszentrum Jülich fears that even then we would not have enough time. “In many areas we will have to make increases of more than a factor of ten and we are not yet moving quickly enough.”
The new theory of colors
Green hydrogen is manufactured from water using electrolysis, with the electricity required coming exclusively from renewable sources.
Gray hydrogen is extracted from fossil fuels, usually from natural gas. For each metric ton of hydrogen, ten metric tons of CO2 are released into the atmosphere.
Blue hydrogen is produced in the same way as gray hydrogen, but the resulting CO2 is captured and stored safely, for example underground. If the CO2 does not reach the atmosphere, it does not contribute to the greenhouse effect and therefore the process is climate-neutral.
Turquoise hydrogen is made by breaking down methane gas at high temperatures. Instead of CO2, this process produces solid carbon, which can easily be stored underground or even used in products such as lithium-ion batteries. The process is only climate-neutral if the energy needed to break down the methane comes from renewable sources.
Red hydrogen is produced by means of electrolysis using electricity generated by a nuclear power station.
A forest of wind turbines – simply for hydrogen
A modern onshore wind turbine with a power output of 3.5 megawatts generates around seven million kilowatt hours per year. This is enough to supply about 2,800 households. To produce a kilogram of hydrogen, the combination of an electrolyzer and a compressor needs around 57 kilowatt hours. This means that using a single wind turbine it will be possible to manufacture around 123 metric tons of hydrogen per year. To meet Germany’s predicted demand of twelve million metric tons in 2050, more than 97,000 wind turbines would have to generate power purely for electrolysis. There are currently around 30,000 wind turbines in Germany.
Theoretical 97,000 wind turbines for H2 production in 2050
Who will be the hydrogen superpower? The global race has begun
Europe is pushing ahead with hydrogen technologies as part of its Green Deal. By 2030, the EU should have electrolyzers with a power rating of 40 gigawatts that produce ten million metric tons of green hydrogen per year. Germany’s federal government is determined that the country will play a leading role in hydrogen technology. In May, more than eight billion euros of federal and state funding was made available for 62 projects that will drive the production, transport, and industrial use of the element.
In the USA, the new President Biden is also promoting hydrogen. His energy minister has recently announced a large-scale project known as “Hydrogen Shot” and plans to spend 400 million dollars on hydrogen projects during the next year alone. The long-term goal is to reduce the price of green hydrogen to one dollar per kilo from the current figure of five dollars. California is playing a pioneering role in this field; the Golden State plans to invest 115.7 million dollars in its H2 fueling infrastructure over the next four years. Hydrogen has already become established as a fuel in niche sectors in the USA. For example, around 40,000 H2 forklift trucks are in operation in the country’s warehouses.
China is continuing to support the use of hydrogen in the transport sector and 50,000 fuel cell vehicles are expected to be on the country’s roads by 2030. The current figure is around 7,000. This relatively high number is the result of generous subsidies that for trucks can amount to as much as 133,000 euros per vehicle. The financial support often comes not only from Beijing, but also from individual cities. The Chinese media have calculated that the country could provide around 100 billion yuan (approximately 13 billion euros) of subsidies for fuel cells in the next four years.