Germany is far more advanced than France when it comes to the configuration of hydrogen energy facilities: Germany has 90 hydrogen refueling stations compared to more than 50 in France. Each service station is worth about 1 million euros. The hydrogen from these hydrogen refueling stations is supplied by tanker trucks.
”I believe that water will one day become a fuel, and that the oxygen and hydrogen that make up water will become an endless source of heat and light.” This moving promise did not come from Elon Musk, owner of electric car maker Tesla, but from Cyrus Smith, a character in Jules Verne’s “The Mysterious Island,” in 1875!
Just as motor vehicles are struggling to break free from the limits of oil and find a transition, not only are electric cars attracting manufacturer after manufacturer, but the development of hydrogen vehicles is not far behind: in 2020, 864 hydrogen vehicles were registered in Europe, including 211 in France, an increase of 40% over 2019. However, it remains to be seen whether hydrogen is indeed as good as it is made out to be and whether there is really a market for such vehicles.
Hydrogen energy, which is effective in heavy-duty vehicles, is eventually expected to be used in buses. While the price is still prohibitive, the advantage of 300 kilometers on a full charge gives it a leg up on pure electric buses.
| A car that emits only water |
For now, hydrogen cars are still a type of electric car, and they power their bodies through a hydrogen-oxygen fuel cell. In this cell, hydrogen and oxygen combine to produce water, which is exhausted from the exhaust pipe in the form of water vapor, and it has almost zero carbon emissions. If a fuel car running 100 kilometers emits an average of 17 kilograms of carbon dioxide, a hydrogen-powered car could shrink its carbon emissions to 1.4 kilograms, according to projections made by the French Montaigne Institute in 2017. However, hydrogen must be compressed before it can be used in the engine, otherwise it will take up a huge amount of space. To have a range of 100 km, a hydrogen car needs 11,200 liters of hydrogen, which is 1/3 of the volume of a tanker, but at a pressure of 70,000 kPa, it can be compressed so that it can be supplied at a hydrogen refueling station. At present, France already has more than 50 hydrogen refueling stations to supply hydrogen for hydrogen cars.
Today, there is no need to worry about the flammability of the fuel for such cars, as the developers have embedded multiple safety systems in the fuel tank. Gerald Bonom, a professor at Lorraine University, said, “The hydrogen cars from Toyota and Honda in Japan and Hyundai in Korea are running very well. It’s a proven technology.”
| Carbon Emissions in Hydrogen Production |
The pursuit of hydrogen energy began in 2002. In his book “The Hydrogen Economy,” Jeremy Rifkin, president of the American Economic Trends Foundation, envisioned a “Jules Verne-style” civilization free from oil and pollution. But in reality, hydrogen is still far from being a clean energy source: 95% of hydrogen comes from fossil sources, especially methane, which is heated to 880°C and mixed with water vapor to separate out the hydrogen atoms, while the remaining carbon atoms combine with oxygen atoms to produce carbon dioxide. Like this, to obtain one kilogram of hydrogen, at least ten kilograms of carbon dioxide are produced! So, although carbon dioxide does not come out of the exhaust pipe of a hydrogen car, it is present in the initial hydrogen production process.
Other ways to produce “green hydrogen” include biomass gasification, which does not require electrolysis. The picture shows researchers doing experiments related to hydrogen production at the Pascal Institute of the University of Clermont Auvergne.
In order to distinguish the way hydrogen is produced, a color classification is used. Black means the source is coal, gray means the source is methane, and blue means the carbon dioxide produced during the hydrogen production process is captured and landfilled. …… “I don’t like these colors. For me, there is only hydrocarbon and no hydrocarbon.” Bonom says bluntly. As it stands, however, hydrogen production is carbon-emitting. The International Energy Agency reports that 70 million tons of hydrogen are used globally each year for industrial production (ammonia industry, steel industry, etc.). France consumes about 1 million tons of hydrogen per year, which means that the carbon dioxide produced during hydrogen production accounts for about 3% of its total carbon emissions.
In fact, there is a more environmentally friendly way to produce hydrogen – electrolysis of water, where electricity simply “breaks” the water molecules to release hydrogen atoms. However, the yield of this form of hydrogen production, which seems to be enough to put fossil fuels out of business, is not promising. “One kilogram of hydrogen produces 33 kilowatt hours of energy, yet it takes 50 kilowatt hours of electricity to make it!” Bonom said. “Energy is never black or white.” Olivier Joubert, a researcher at CNRS and member of the French Hydrogen Fuel Cell Association, agrees.
In its June 30, 2020 report, the French Institute of Technology also said, “In order to promote the use of hydrogen for transport, we need to increase the amount of electricity produced by nuclear power plants.” But this is something that some countries are unable to do: immediately after the Fukushima nuclear leak, Germany decided to abandon nuclear power and go back to using coal to generate electricity. As a result, 1 kilogram of hydrogen made through electrolysis of water produces 25 kilograms of carbon emissions in Germany. In other words, hydrogen cars in Germany are less environmentally friendly than conventional cars!
|Is “green hydrogen” a fantasy? |Is “green hydrogen” a fantasy?
France is torn between non-nuclear hydrogen and nuclear hydrogen. Unless there is a completely environmentally friendly option – “green hydrogen” – that underpins all the optimistic visions surrounding hydrogen vehicles. “‘Green hydrogen’ is the hope by which alone we can be truly carbon neutral by 2050.” So say four French researchers in the magazine “The Developing World” in 2020. To do so, we must use the “recipe” of electrolysis of water, but here the electricity must be generated exclusively from renewable sources, such as wind, solar and perhaps in the future, biomass. The director of a hydrogen refueling station in Sargemine, Moselle, France, said that since 2017, they have been providing customers with hydrogen fuel produced entirely from renewable sources.
But for now, the manufacture of “green hydrogen” remains marginalized: it accounts for only 5% of global hydrogen production. The reason is that the conditions for manufacturing “green hydrogen” are difficult to control: it is susceptible to weather and is extremely seasonal. “Is solar and wind energy enough? The answer is no.” says Bonnom. The French Institute of Technology shares this view: “If hydrogen cars account for 1/3 of the current car fleet in France, then with their demand for ‘green hydrogen’ we would need nearly 300 TWh of electricity, which is far more than the amount of electricity produced from 100% renewable energy. ” In 2020, France as a whole will produce 52.3 TWh of electricity from solar and wind, which is only 1/6 of the electricity needed for “green hydrogen”.
| Battery Issues |
Like purely electric cars, hydrogen cars are equipped with a battery that holds the electricity generated by a fuel reactor. However, the batteries of hydrogen cars have come under the same fire: the production process is very energy intensive and requires the use of rare metals, especially platinum, one of the world’s most expensive metals (worth more than 25,000 euros per kilogram).
The “hydrogen economy”, as Rifkin calls it, could cause demand and prices for platinum to soar, causing a major geostrategic reshuffle. Platinum production is extremely high in some places: about 70% of the world’s platinum comes from South Africa, with Russia in second place (12%), followed by Zimbabwe (7%), Canada and the United States. As a giant in the platinum market, Pretoria, South Africa, may hold the key to energy in the hydrogen era.
However, while this scenario is worrisome, hydrogen fuel cell advocates are already seeking to rule it out. The French Hydrogen Fuel Cell Association says progress has been made in the area of platinum recovery, “Recent technological innovations have reduced the platinum content of the cell to 1/2000th of its previous level! platinum catalyst. “Hydrogen technology still needs to improve,” says Joubert, “and we need to reduce the percentage of platinum in batteries. We’ll get there.”
| The “hydrogen car” that burns money|
”The problem with hydrogen cars is that they don’t offer any economic or energy advantages.” Bonhomme lamented, adding that the class of cars consumes four times more electricity than conventional electric cars. Frederic Levet, director of the French National Center for Scientific Research, is even more pessimistic: “The energy conversion efficiency of fuel cells is hardly more than 50 percent, and with other losses, the true conversion efficiency from hydrogen to electricity is only 40 percent.” In other words, 60% of the hydrogen obtained after all the hard work is wasted. Users of hydrogen cars are afraid they will have to watch their wallets shrink: hydrogen refueling stations are expected to sell hydrogen for around 10 euros per kilogram. “This energy source will not be cheap, even in the long run.” According to Felix Mattes, a member of the French National Hydrogen Energy Commission.
It is not only fuel that is expensive, but also cars. At 500 to 1,000 euros per kilowatt for the engine, a Toyota Mirai – a simple four-door sedan – costs more than 70,000 euros, while a Hyundai Nexo reaches 80,000 euros.
As the French Institute of Technology says, the government also has to build the infrastructure from scratch, “investing at a time when the demand is not yet there, and at the moment it seems that only the government will take that risk.” The German Research Center in Jülich estimates that 20 million hydrogen cars would cost 50 billion euros to manufacture. The French government announced in September 2020 that it would spend €7 billion on hydrogen energy sector development by 2030, but private cars are not included.
In 2018, the French Atomic and Alternative Energy Commission published the Hydrogen Energy for Energy Transition Program. In this program, the direction is very clear: the energy transition should focus on electrical energy and biomass fuels, with hydrogen as the last resort. This direction is mainly aimed at trucks and buses: under the pressure of environmental policies, the thermal engines of these two types of vehicles need to be gradually replaced by new engines. However, for heavy vehicles, once the power cell exceeds a certain volume, it does not produce enough energy to supply the vehicle for long distances. “The immediate approach should be: use as much electricity as possible and produce hydrogen energy on demand.” Mattes concluded.
So it seems that there is little hope for a future world ruled by hydrogen vehicles, which is precisely the conclusion that Toyota has released in its 2020 development plan. Toyota only plans to use hydrogen energy for heavy trucks, logistics vehicles and buses. So how do you explain the sleek lines of the Mirai sedan that Toyota has launched? “Toyota is a pioneer in hydrogen energy,” says Roubel, “but the Mirai’s battery can actually be used in a truck.” So the Mirai is like a more beautiful and persuasive window display for the public than a heavy truck, showing the viability of hydrogen technology. But more importantly, it confirms the point that Cyrus Smith’s prophetic words in “Mysterious Island” can ultimately only exist in fiction.
[Compiled from French newspaper “?a M’ intéresse”].
Edited by Hou Yin
In 2020, 10,480 hydrogen-powered vehicles will be registered worldwide. South Korea’s Hyundai says the Nexo is capable of a range of 666 kilometers. The global hydrogen production is responsible for 830 million tons of CO2 emissions per year.
Source: International Energy Agency
How do hydrogen cars work?
A hydrogen car works on the same principle as an electric car, but because it can generate its own electricity, it has twice the range of an electric car.
Initial trials of hydrogen-powered cars put engineers in a dilemma: should they opt for the classic reciprocating internal combustion engine or should they incorporate hydrogen into an electrical system. The first solution attracted the attention of some car manufacturers, among them BMW – who thought they could play to the strengths of their own engine manufacturer. Only unfortunately, the popularity of electric cars and the inefficiency of hydrogen internal combustion engines eventually made the German manufacturer abandon its development plans. Today, the technology for hydrogen fuel cells is so mature that hydrogen cars have been able to reach a range of 700 kilometers.
Electric engines
The engine of a hydrogen car is not fundamentally different from that of a normal electric car. In terms of performance, hydrogen cars are no less powerful. The Toyota Mirai2 can reach a maximum power of 182 hp and a maximum torque (acceleration force) of 300 Nm. From these figures, it is second only to the Mercedes-Benz A-Class sedan – it can pick up speed to 100 km/h in less than 10 seconds.
Battery power module
This module is like the “brain of the car”, which controls the operation of the engine and the generation of electric current according to the driver’s actions. In order to control the cost of the car’s electrical system, engineers designed it to be placed next to the engine. However, this choice also has its drawbacks, because the module has temperature requirements and must be between -40°C and 160°C to operate properly.
The battery
It is the left and right arm of the fuel cell. The current generated by the fuel cell varies depending on the usage, and if the current is too low to meet the driver’s boost requirements, then the battery is engaged. During smoother driving phases or when braking, the battery is able to store or recover the electrical energy produced by the fuel cell.
Water vapor
This is the main advantage of a hydrogen car: water vapor is its only emission.
Hydrogen bottle
The hydrogen bottle is the main safety component of a hydrogen-powered vehicle. In order to put the hydrogen under a pressure of 70,000 kPa, the hydrogen bottle is designed to be particularly heavy: the 95 kg tank is designed to store only 5 kg of hydrogen. Since hydrogen is very flammable, the hydrogen bottle uses a metal or polymer housing in order to prevent impacts and ignition sources from igniting the hydrogen. Its valve device ensures that hydrogen can be quickly discharged in the event of an accident.
How the hydrogen fuel cell works
The hydrogen fuel cell, the core component of a hydrogen car, converts hydrogen energy into electricity. This cell is expensive because platinum is commonly used as a conductor.
1. Hydrogen is sent to the anode plate (negative terminal) of the fuel cell, while oxygen is allowed to enter the cathode plate (positive terminal) of the cell.
2. A hydrogen atom is decomposed into two positively charged hydrogen ions and two negatively charged electrons.
3. The hydrogen ions pass through a permeable exchange membrane to the cathode plate (positive) of the battery, but the electrons cannot pass through the exchange membrane.
4, Electrons flow through the wire (platinum) between the anode and cathode plates of the battery, and the current generated by the flow is used to feed the engine.
5, Hydrogen ions and electrons recombine with oxygen at the cathode plate (anode) to produce water molecules, which are then exhausted by the car in the form of water vapor.
