Climate change has prompted governments to take action to reduce their greenhouse gas emissions. With road transport responsible for almost a quarter of emissions, it is no surprise that new regulations against combustion engines have been introduced. As a result, manufacturers have taken advantage of the availability of public funds to develop greener technologies. As a result, battery-electric cars have become an integral part of our daily lives. But what about the hydrogen car?
Of the many new propulsion systems, electric motors have taken the lead. Generally speaking, when we talk about electric cars, we think of vehicles with rechargeable batteries. This is typically the case with Tesla or the VW ID3. However, there are other technologies available to create the electricity that powers the vehicle. One of these is the fuel cell, also known as the hydrogen fuel cell. In this article, we discuss this relatively unknown system.
How does it work?
Technology
Hydrogen cars are not the same as cars powered by natural gas or LPG. They are closer to electric cars than to those with internal combustion engines. Hydrogen cars are equipped with a tank to store hydrogen (H₂). The gas is then transferred to the fuel cell, which has an anode (positive electrode) on one side and a cathode (negative electrode) on the other. As the hydrogen atoms enter the fuel cell, they pass over the anode, thus isolating the protons (positively charged particles) from the electrons (negatively charged particles). A polymeric electrolyte membrane redirects the electrons towards the electric motor used to power the vehicle. The protons pass through the membrane. At the cathode, the protons and electrons are mixed with oxygen (O₂) to create water. This water is the end product of the reaction that makes the vehicle work. The car then disposes of it. There is therefore no gas emission.
Hydrogen cars are also equipped with a low capacity battery. This allows energy to be stored and released when necessary, especially when an acceleration requires more power.
Safety
Safety seems to be one of the main concerns when it comes to fuel cells. Indeed, hydrogen is compressed at high pressure (between 350 and 700 bar) inside the tank. However, the risk of explosion is (almost) non-existent. The homologation tests carried out on the tanks are extreme and more extensive than for products with combustion engines. In addition to the highly resistant tanks, auxiliary systems ensure the occupants' safety. For example, the hydrogen supply system is automatically switched off in the event of an accident. Also, ventilation systems are activated if gas is detected in the cabin. Thus, hydrogen cars are as safe as any other car.
Is it really environmentally friendly?
As explained above, hydrogen cars do not release any harmful gases into the atmosphere. The product resulting from the combustion is H₂O, better known as water. In addition, the battery capacity is low, which limits the need for metals. This propulsion system is therefore rather environmentally friendly.
However, the processing of liquid hydrogen is a serious challenge. Transporting and compressing it requires a lot of energy. It is important to point out that no car is completely ecological. The combustion engine emits many harmful and greenhouse gases, while battery-powered cars require large quantities of metals, the extraction of which is often polluting and ethically questionable. In its current form, the hydrogen car is therefore relatively green.
What are the advantages and disadvantages?
Advantages
Hydrogen cars have several advantages:
Firstly, as explained in the last paragraph, the hydrogen car is quite green. Also, hydrogen is not really limited in quantity as it is the most abundant element in the universe.
Compared to battery-powered cars, hydrogen cars are light, as they are equipped with a small battery only. This reduces the overall weight of the vehicle and improves its driving dynamics.
Some governments offer incentives for low or non-polluting vehicles. In Switzerland, the benefits vary by canton.
Filling up the tank takes the same time as for petrol vehicles. Also, there is no need to recharge the battery.
Disadvantages
Nevertheless, hydrogen vehicles still suffer from serious drawbacks:
The lack of infrastructure is enormous. The first hydrogen station was opened in 2016 in the canton of Aargau. Since then, only about ten stations have been added to the Swiss territory. In comparison, there are over 3,600 public charging stations in Switzerland. The number of filling stations is even higher.
In contrast to rechargeable cars, the costs of running a fuel cell car are not particularly attractive. The cost of a full tank of hydrogen is comparable to that of a full tank of gasoline or diesel. If the number of fuel cell vehicles increases, these costs should decrease.
Which models are currently on sale?
Currently, only two hydrogen cars are available on the Swiss market: the Toyota Mirai and the Hyundai Nexo. However, other projects are in development.
Conclusion
The hydrogen car appears to be an attractive proposition. It combines the ecological advantages of the electric car with the ease of use of the combustion engine. However, the current disadvantages remain significant. The lack of infrastructure is a real obstacle to the adoption of this technology. In addition, the limited offer reduces its visibility and attractiveness. In order to overcome these disadvantages, significant investments need to be undertaken by the private sector and public authorities. Due to limited financial resources, only a few technologies are expected to establish themselves in the long term. The future will tell whether hydrogen is one of them.
If you are not sure which car is right for you, or if you simply cannot find it, contact Carequest! We will be happy to help you.
Sources - text
https://www.futura-sciences.com/sciences/actualites/univers-element-plus-abondant-univers-90978/
https://www.h2-mobile.fr/dossiers/fonctionnement-voiture-hydrogene-comment-ca-marche/
https://www.swiss-emobility.ch/fr/electromobilite/Mesures-d-aide-/
https://www.tcs.ch/fr/tests-conseils/conseils/mobilite-electrique/bornes-recharges-publiques.php
Styczynskia, A. B., & Hughes, L. (2019). Public policy strategies for next - generation vehicle technologies: An overview of leading markets. Environmental Innovation and Societal Transitions, 31, 262-272. https://doi.org/10.1016/j.eist.2018.09.002
Ritchie, H. (2020, October 6). Cars, planes, trains: where do CO2 emissions from transport come from? Retrieved March 2021, from Our World in Data: https://ourworldindata.org/co2- emissions-from-transport
Sources - photos
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