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Hydrogen Cars: Beyond the Innovation – How Safe Are They

By Amirah Tan Last updated November 16, 2023
are hydrogen cars safe

Based on extensive research into hydrogen cars, they are the next innovative zero-emission vehicles to succeed electric cars. They rely on the combination of pressurized hydrogen gas and oxygen to generate electricity for the wheels. The electricity produced offers more power to the wheels than what an electric car battery can provide. The result is the ability to drive faster speeds and longer distances with a hydrogen car.

Are Hydrogen Cars Safe?

Yes, hydrogen cars are safe to drive. In some ways, they are safer to drive than ordinary gasoline-powered vehicles. You will learn more about that as you read on down below.

Why It’s Safe to Drive a Hydrogen Fuel Cell Car

When talking to people about hydrogen cars, their number one concern is about their level of safety. They always ask me, “Isn’t hydrogen highly explosive like a hydrogen bomb?” Technically, hydrogen is as flammable as gasoline. But the hydrogen gas in the hydrogen fuel tanks of cars is secured far better than gasoline fuel in petrol cars.

Based on extensive research, it’s evident that hydrogen fuel tanks are constructed from highly durable reinforced carbon fiber material. After numerous test crashes, this carbon fiber material has proven resistant to damage from most ordinary vehicle collisions. On the other hand, the gasoline in petrol vehicle fuel tanks can suffer damage and punctures in vehicle collisions more easily. The result is gasoline leaking out and becoming susceptible to igniting on fire.

Hydrogen fuel is also safer to use than gasoline or diesel fuels because it has a higher auto-ignition temperature than gasoline and diesel. For instance, the auto-ignition temperature of hydrogen is approximately 575°F, whereas the auto-ignition temperatures of gasoline and diesel are 500°F and 345°F, respectively. It takes more heat to ignite hydrogen into a fiery explosion than the other two.

 are hydrogen cars safe

are hydrogen cars safe

Here are some more interesting facts about hydrogen cars and hydrogen fuel itself:

  • Hydrogen is 14 times lighter than air, allowing it to disperse quickly into the atmosphere. This reduces the risk of fire and explosion in case of leakage after an accident.
  • Hydrogen gas flows into the anode of the fuel cell. The anode splits the gas into positively charged ions and negatively charged electrons.
  • Oxygen flows into the cathode of the fuel cell.
  • The polymer electrolyte membrane in the middle of the fuel cell allows positively charged ions from the anode to enter the cathode. It also passes electrons from the anode to the external electric circuit and the cathode.
  • The ions and electrons unite with the oxygen to produce electricity for the vehicle. Water emissions are released from the tailpipe.
  • It only takes 3 to 5 minutes to fill your hydrogen fuel tank with hydrogen gas. The process is similar to how you pump gasoline into a petrol fuel tank. You simply stick the nozzle of the hydrogen fuel dispenser into the receptacle of the hydrogen fuel tank. Once it finishes, close up the receptacle door and start up your vehicle.

Check out this video to learn more about how hydrogen fuel cell cars are safe to drive and refuel at hydrogen gas stations:

 

Addressing the Safety Concerns of Hydrogen-powered Cars

All gases have a risk of exploding depending on their pressure. But when you think about all the high-pressured gases we already use in our daily lives, such as liquified petroleum gas and compressed natural gas, you will realize that they are safe to use as long as the proper safety precautions are taken.

Are hydrogen cars safe in a crash?

Hydrogen cars are as safe as petrol cars in a crash. As indicated above, hydrogen gas is still highly flammable, except it has a higher ignition temperature than gasoline. So, there is a higher level of safety with hydrogen cars because it takes a slightly higher temperature for the hydrogen gas to explode. But that is not something you should depend on to save your life.

Your hydrogen fuel tank can still be damaged in a car crash, even without an initial fuel leak. Its carbon fiber-reinforced plastic material may be strong, but it is not 100% resistant to the massive impact and force of a major auto collision. A robust crash could cause the threads of the fiber to rip apart if the force of the crash is powerful enough. If that happens, the hydrogen gas would emit into the air.

Ultimately, you bear the same level of risk in a hydrogen car crash as you would in a petrol vehicle car crash. The usual safety risk of a car crash has more to do with the impact on the driver than on the fuel tank. So, if you remember to wear your seatbelt and drive as safely as possible, you will have the best chance of avoiding serious injury if someone else crashes into you.

Take a look at the video below for insights on the safety of hydrogen cars. 

 

Hydrogen’s flammability and potential risks

Hydrogen gas by itself poses no danger to anyone. However, enormous pressure needs to be added to hydrogen gas to increase its efficiency in generating electricity for hydrogen vehicles. Anytime more pressure is added to a flammable gas, there is a higher risk of explosion. And since 700 bar of atmospheric pressure is applied to hydrogen gas fuel, it can be highly explosive without the proper safety precautions.

Standard steel fuel tanks can quickly explode in extreme temperatures. Fortunately, hydrogen fuel tanks are made from reinforced carbon fiber, which is 10 times stronger than steel. Not only that but additional fire-resistant material is installed on the inside and outside of the hydrogen fuel tanks for extra safety and security.

In addition, the hydrogen fuel tanks contain safety valves designed to immediately release the internal pressure of the tanks if they are exposed to flames or extremely high temperatures. That way, there is a much less chance of an explosion occurring if the internal pressure is lowered while exposed to dangerously high temperatures.

Read also: Pros and Cons of Hydrogen Fuel Cell Cars

Challenges in storage and transportation

Storing and transporting hydrogen fuel is more complex than traditional gasoline and diesel fuels. According to the U.S. Department of Energy, hydrogen is more difficult to store because it has low energy content by volume. Because of this, lower temperatures and higher-pressure conditions are required to store the hydrogen gas safely and securely.

Heavier hydrogen vehicles are more easily storing hydrogen than light-duty vehicles. The problem with light-duty vehicles is they have a limited load size and weight capacity, especially when storing fuel. Even though hydrogen has less volumetric energy density than gasoline, a hydrogen car still needs a larger, high-pressure fuel tank to store the hydrogen gas.

Heavy and medium-duty vehicles have enough space to store a large hydrogen fuel tank, while light-duty vehicles do not. This challenges auto manufacturers wishing to create smaller hydrogen vehicles, such as sedans and pick-up trucks. The weight limitations of these vehicles simply cannot sustain a large hydrogen fuel tank.

Of course, I am optimistic about the technological innovativeness of major auto manufacturers like Toyota, Honda, and Hyundai. They have already created impressive hydrogen light-duty vehicle prototypes and concepts which can still travel over 300 miles before needing to be refuelled.

 

Real-World Incidents and Experiments

Do you still need more convincing that hydrogen cars are safe? Having been featured in reputable publications, I can attest that the Hyundai Nexo is a safe hydrogen fuel cell car.

All South Korean hydrogen vehicles for sale like this one must pass the safety assessment test of the Korean Transportation Safety Authority. They must also pass the safety test of the United Kingdom’s Vehicle Certification Agency and the vehicle safety tests in hydrogen tanks certifications of the Technical Inspection Association of Germany.

In 2018, the latest Hyundai Nexo was chosen as the safest hydrogen SUV in Europe. Part of the reason was that it passed a collision test performed by a U.S. nonprofit vehicle safety institute called “Insurance Institute for Highway Safety.” It also received the highest rating in six rating categories, such as moderate overlap front, driver-side small overlap front, passenger-side small overlap front, side roof strength, head restraint, and seat.

Hyundai’s testing proves they care about safety. In terms of the hydrogen fuel tank, the company conducts numerous hydrogen fuel tank safety assessments on its vehicles, such as drop flame and extreme temperature tests, to ensure the safety valves quickly reduce the internal pressure to prevent explosions.

Learn more about the safety tests performed on the Hyundai Nexo hydrogen car.

Read also: 10 Best Hydrogen Cars Revolutionizing the Future of Driving

Summary

All gases have a risk of exploding and causing fires. But based on my experience driving hydrogen vehicles and researching the science behind them, I can safely say they have a far less chance of causing injury or death than petrol vehicles. The limited number of hydrogen cars built as prototypes and concepts have proven to be durable, secure, and safe for drivers and passengers during and after collisions.

Amirah Tan

Amirah Tan, blending computer science expertise with a grasp of social dynamics, offers unique insights into Malaysia's software-society interface. Her...

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