How do hydrogen cars work?

Hydrogen cars (H2) are vehicles that use hydrogen fuel for motive power, making them energy-efficient alternatives to gas-powered cars. Hydrogen fuel cells use hydrogen and oxygen to create electricity that powers a motor. 

Companies such as Toyota are investing in this fuel of the future as an alternative to harmful gas or electric-powered vehicles. Currently, there are an estimated 11,000 hydrogen cars on the road today. 

Why hydrogen? The U.S., Japan, China, and South Korea are making big investments in the future of hydrogen as an alternative and more sustainable fuel source. Toyota is leading the research in this field and is working to make a hydrogen vehicle future attainable and affordable. Read on to discover how hydrogen fuel cells work, the pros and cons of H2 vehicles, and more, or jump to our infographic for a visual aid. 

How do hydrogen fuel cells work?

Hydrogen fuel cells are made through a REDOX (reduction/oxidation) reaction between hydrogen and oxygen. This process directly converts energy into electricity, using hydrogen as the fuel and combining it with oxygen from the air to create an electrochemical cell. The end result is emissions made of electricity and water vapor.

A fuel cell is composed of two electrodes, an electrolyte, fuel (hydrogen), and a power supply. The reduction and oxidation reaction happens through a multi-step process involving the anode, the cathode, and the electrolyte membrane.

At the negatively-charged anode site, hydrogen molecules are split into electrons and protons. The electrons are then forced through a circuit where they generate an electric current and excess heat. The protons go on to the electrolyte membrane. At the cathode, the protons, electrons, and oxygen combine to produce water molecules. Flow plates facilitate the transfer between the anode and cathode.

Because an individual fuel cell only produces less than 1.16 volts of electricity, fuel cell stacks are needed to increase the amount of electricity generated.

The pros and cons of a hydrogen car

The current landscape of the auto industry is unsustainable, with carbon emissions now widely accepted as a direct contributor to climate change. Automakers are hoping H2 vehicles can provide an alternative to gas-powered vehicles and the battery-powered electric vehicles that have made waves over the past few years. Here are some of the pros and cons of hydrogen cars technology: 

Pros

Eco-friendly emissions: Pure hydrogen cells emit only water and heat, eliminating concerns around air pollutants or greenhouse gases.

Fast refueling: A hydrogen-powered vehicle can be refueled in about the same amount of time as a gasoline-powered vehicle — five minutes. Battery-electric cars can take anywhere from 30 minutes to hours to recharge.

Long range: Like gasoline-powered cars, hydrogen cars can travel 300 to 400 miles before they need to be refueled.

Cons

Lack of access: Infrastructure is the biggest challenge facing hydrogen cars. Refueling stations will need to be built throughout the world; currently, the U.S. only has 14.

High cost of production: The small scale of production makes hydrogen cars more expensive than their battery-electric counterparts. The cheapest hydrogen-powered Toyota is $57,500.

Limited options: Consumers have extremely limited options when choosing H2 vehicles. Only four automakers are currently investing in H2 car production: Toyota, Honda, Hyundai, and Mercedes.

What are the differences between fuel cell cars and other EVs?

Because hydrogen fuel cell cars are powered by electricity, it is a type of electric car, but unlike other battery-powered electric vehicles, hydrogen cars have a hydrogen fuel cell in lieu of a battery. This fuel cell recharges faster (in as little as five minutes!) and produces electricity while the car is running.

Check out our visual below to see how hydrogen cars work and what the future of electric cars looks like in the U.S. through 2030. 

Sources: 

FCHEA | FW:THINKING | NPR | Fuel Economy | IEA Fuel Cell | Hydrogenics