What is Hydrogen and how do hydrogen cars work?
- Camilla Coletta
- May 27, 2024
- 7 min read
Hydrogen cars are getting closer and closer to being a new reality on the track, especially in the World Endurance championship. In fact, for years ACO and MissionH24 have been working to insert hydrogen powered cars into the WEC, but they are not the only ones.
"With the introduction of hybrid prototypes to the 24 Hours of Le Mans, the reduction in fuel consumption was remarkable. A revolutionary step has been made with the electric-hydrogen propulsion prototypes since they are zero emission competition. A car equipped with an electric-hydrogen powertrain releases only water vapor into the atmosphere."
Said Bernard Niclot, Director of Innovation of the MissionH24 program.
But what is hydrogen and how could it replace fossil fuels?
Defined as a safe, efficient, versatile and emission-free fuel, hydrogen is, in fact, a fuel that has the distinction of not emitting CO2. But if it doesn’t emit carbon, what is the waste product of hydrogen? The answer is Water. Yes, hydrogen, reacts in contact with oxygen, producing energy and water as the only waste element.
A fuel with zero emissions, but it has a big flaw: it is true that this element is present in huge quantities in nature but always linked to other elements, and it is precisely this that makes it unusable in the state in which it is naturally. It then becomes expensive to extract and would require amounts of energy that would "not be worth it" as it would be more waste than gain.
This is the biggest obstacle of this type of fuel that does not make it the best choice yet, but it is not the only one.
Hydrogen storage is another big problem as this gas is not very dense and therefore takes up a lot of space in the gaseous state. A manufacturer had thought of another way of storage, that is to liquefy it, but the hydrogen remains liquid only at temperatures below -253ºC and the challenges were not missing.
Moreover, because hydrogen is a very small molecule, it can surpass many materials that would apparently look solid, thus escaping from tanks and becoming potentially dangerous.
How does a hydrogen combustion engine work?
A hydrogen engine can be a great resource in terms of reducing emissions, although it is very important to make distinctions on the type of engine but, above all, the origin of hydrogen as this can be green (from renewable sources) or less (from fossil fuels).
When we talk about hydrogen engines it is important to make a distinction. In fact, there are two completely different types of hydrogen engine: the fuel cell system and the hydrogen-powered thermal engine.
Fuel Cell System
The Fuel cell system is an engine composed, as the name implies, of combustion cells that transform the chemical energy of hydrogen into electric energy thanks to the chemical reaction that takes place between this element and the oxygen in the air. This chemical reaction allows the electrons extracted from hydrogen to create energy that will then be stored in a battery, without any combustion, we can therefore say that this system is approaching the operation of an electric machine, The difference lies in the fact that the car is not powered directly by connecting it to the current, but this is generated thanks to the hydrogen circuit.
Hydrogen powered thermal engine
The hydrogen-powered thermal engine is completely different from the Fuel Cell system. The hydrogen combustion engine has a similar function to fossil combustion engines (gasoline or diesel), the difference is that the gas is burning. When hydrogen enters the combustion chamber it encounters the oxygen present in the air, this process allows, when the gas burns, the piston to move, thus transforming chemical energy into mechanical energy.
It is important to note that this type of engine cannot be considered zero-emission. It is true that hydrogen, in its pure state, does not contain carbon and therefore is not able to release it, but during the combustion of this gas, nitrogen and oxygen (ambient air) participate and this reaction between the elements can release oxides of nitrogen, considered very polluting.
Mission H24
Mission H24 is a project that was born in 2018 by GreenGT and ACO that aims to bring hydrogen powered cars on track. This program has already given birth to several prototypes, using this technology, that have been taken to the track over the years proving that hydrogen could get to race in Le Mans.
In 2022, for the first time, a MissionH24 prototype was entered into a championship, the Michelin Le Mans Cup, with the H24 in the "experimental" category participating in 4 races of the championship.
In October 2023, the new prototype of MissionH24: H24 EVO, a prototype that will be tested on the bench from October 2024 and should be on track from January 2025 for the first circuit tests.
This year, for the occasion of the ninety-second Le Mans, on June 15, 2024, before the race, several hydrogen prototypes will step on track, including Ligier-Bosch with the Ligier JS2 RH2, a car equipped with a H2 thermal engine, and the H24 of MissionH24, a prototype fitted with a Fuel Cell electric engine. Joining them there will also be the Alpenglow Hy4 of Alpine.
"This June 15 2024, will mark the history of the 24 Hours of Le Mans. For the first time, the hydrogen prototypes will evolve on the grand circuit of Le Mans with the h24 of our missionh24 program. The Ligier JS2 RH2 faces this challenge and I’m excited about it. This demonstration is much more than symbolic, it demonstrates the merit of missionh24 that participates in the creation of a hydrogen category at the 24 Hours of Le Mans with vehicles engaged by manufacturers. With hydrogen, endurance races prepare for sustainable competition."
Said the president of the automobile club de l'Ouest Pierre Fillon.
The reliability of the Fuel Cell hydrogen engine
On the official website of MissionH24, they talk about hydrogen engine as "perfect for endurance racing" because its reliability is very high thanks to the particular formation of the hydrogen engine formed by no moving organ, but in reality they're talking about the Fuel Cell system, the one used in the H24.
Hydrogen Class: will there really be a future of zero-emission racing?
The ACO’s mission towards decarbonization, although there are still improvements to make, continues and, by 2027, the arrival of the first car for the hydrogen category is expected at Le Mans: Hydrogen. The arrival of the Hydrogen class for manufacturers, however, is scheduled for 2030.
The arrival date at Le Mans of the category continues to slip, this because, as Pierre Fillon said, there are still some changes to be made in the safety area which they are currently working on.
The largest car testing bench, the WEC, has been working on hydrogen-powered prototype designs with Powertrain fuel cell technology for years, but in the Hydrogen category the hydrogen combustion engine will also be allowed.
Meanwhile, according to Pierre Fillon, the regulations for this new category are in the works and will be effective from 2027. In addition, the president of the Automobile Club de l'Ouest told motorsport.com about hydrogen engines and the new category:
"It will be a new technology and it will take a year or two for it to become fully competitive, but the regulations are designed to allow a hydrogen car to win. Next month at Le Mans there will be an important announcement about hydrogen."
But who will be competing in this category? It is still too early to define who the competitors will be, even if, apparently, eight manufacturers are interested at the moment. There is no certainty about the names, but we had the opportunity to see the GR H2 Racing Concept of Toyota at Le Mans last year and Alpenglow of Alpine at Spa last weekend. Two concept cars that make us understand that even manufacturers are getting closer to this reality.
Toyota
Toyota with the GR H2 Racing Concept was presented at an ACO press conference on the 9th of June of last year at the 24 Hours of Le Mans. A new very important piece for the Japanese company that, for the first time, presented a prototype car with a hydrogen-powered thermal engine.
The specifications of the GR H2 Racing Concept are to date unkown, except that the engine designed is a hydrogen engine combined with a hybrid system.
But it was not the first time that Toyota approached this new reality: in 2021, in fact, a Corolla with hydrogen engine stepped on track in the Super Taikyu Series and, the following year, in the IDEMITSU 1500 SUPER ENDURANCE 2022 for some stages.
L’utilizzo di idrogeno liquido con la Corolla H2
In 2023 Toyota GR steps on track, for the first time in the world, with a car that used liquid hydrogen. A choice, as mentioned above, smart from the point of view of reducing the space of hydrogen storage, which also allowed to double the autonomy of the car with the same time of refueling; even the pit-stops were faster and more efficient, as the refueling could be carried out in the same area where it was carried out by the other competitors thanks to the smaller filling stations and a shorter number of necessary refueling.
But it is good to remember that hydrogen remains liquid only at very low temperatures that, to be maintained, they need a system that has significantly increased the weight of the car and that has made it difficult to develop fuel pumps capable of maintaining such low temperatures which that did not evaporate the gas during the introduction into the tanks.
The Corolla H2 was not only a challenge for the Japanese company and for the increase in technology, but it was the demonstration that this type of engine can really compete in endurance racing, finishing the 24 Hours of Fuji.
Alpine
Alpine presented a concept car with the name Alpenglow Hy4 taking it to the track this year at the weekend of the 6 Hours of Spa with demonstrations. Alpenglow has a 4-cylinder development engine and a V6 engine designed entirely by Alpine to be powered by hydrogen, rear-wheel drive with 340 horsepower and a 7-speed transmission.
The cockpit of the French company’s concept car has two seats, enclosed in a futuristic design of the body entirely in carbon carved specifically for the track, although this car is also designed for the road. The design of Alpenglow is designed to withstand the high pressures of cylinders for the combustion of hydrogen, the storage of the latter is pressurized and capable of containing over 6 pounds.
Bruno Famin, VP Alpine Motorsports:
"As part of our active participation in the decarbonization of motorsport, we see the hydrogen internal combustion engine as an extremely promising solution. Hydrogen could very well be an essential step in the decarbonization of the next generations of Formula 1 and Endurance cars, especially moving to the storage of liquids in the future to improve performance. The Alpenglow concept perfectly illustrates this, a real technological laboratory for the development of tomorrow’s hydrogen engines."
This is not the definitive model; a new version of Alpenglow is planned before the end of the year. The Alpine concept car underscores the French manufacturer’s commitment to decarbonizing sports cars not only on the track but also on the road while maintaining high but sustainable performance.
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