How safe are hydrogen fuel cell cars in a crash?

How safe are hydrogen fuel cell cars in a crash?

May 1, 2020 2 By Bret Williams

Cars powered by gasoline need firewalls to protect from fire, but what about safety in alternative fuels?

Hydrogen fuel cell cars are becoming increasingly promising as the technology develops, particularly in the shipping and goods transportation industries as well as industries such as mining.

That said, one of the main hurdles faced by this alternative energy is in perception of its safety.

There are currently only a few types of hydrogen cars around the world. When it comes to passenger cars, the focus has been greatly directed toward rechargeable electric battery powered options. Still, there are heavier trucks, ships, trams, trains and machinery powered by H2.

Moreover, there are only a handful of cars available, such as the Hyundai Nexo and the Toyota Mirai. They each have storage tanks for the H2 and function by converting it into electricity which powers their drive wheels. The only emission resulting from this process is water, making this it eco-friendly and attractive for that reason.

UPDATED LIST OF HYDROGEN CARS IN PRODUCTION 2021:

2008–2015 – Honda FCX Clarity
2013–2017 – Hyundai Tucson/ix35 Fuel Cell
2015–2020 – Toyota Mirai
2016–2021 – Honda Clarity Fuel Cell
2018 – Hyundai Nexo
2020 – Toyota Mirai II

Many people fear the risk of explosion when they think of hydrogen fuel vehicles.

Though many of us think of this type of fuel as highly explosive, this is based on a common misconception. The Hindenburg is a typical example of what people consider to be the dangers associated with hydrogen, however, that disaster was caused by the fabric of the blimp and not nearly as much by the gas.

In fact, many feel that H2 can be considered to be considerably safer than cars powered by gasoline. Primarily, if there is a gasoline leak, there is a mess and a significant fire risk. In the event of a hydrogen leak, the gas simply dissipates harmlessly.

Moreover, the tanks that contain H2 are thick walled and carefully designed to prevent leaking, even after a substantial crash. The tanks in the Mirai, for example, are carbon fiber wrapped and can withstand a .50 caliber bullet without suffering a leak. The Nexo are made differently but can withstand the pressure of the gas up to 10,000 psi.

hydrogen fuel cell cars motor and tank safety

*image credit U.S. Department of Energy.

The tanks in hydrogen fuel vehicles also feature relief devices that cause the gas to be vented in certain circumstances in order to avoid heat-induced explosions.

For example, should the tanks ever be punctured, the device allows for a managed venting of the gas. Sensors throughout the vehicle also work to detect unexpected gas presence to shut everything down and bring the vehicle to a stop before anything can be permitted to ignite.