Anyone thinking about buying a new car over the next couple of years may be introduced to an entirely new breed of vehicles: fuel cell cars. They're not exactly ready for sale today, but in the coming years everyone will be hearing from several car manufacturers that have these vehicles in the evaluation stage right now.
The engines used by fuel cell vehicles are a radical departure from the internal combustion engines installed in cars today. Just like electric vehicles, these cars are powered by electric motors. But unlike electric vehicles that depend on a sophisticated array of batteries to store energy, fuel cell cars have the ability to create their own electricity.
Using a chemical process, fuel cells are able to convert hydrogen fuel, and oxygen from the air, to produce electricity. The fuel is stored as hydrogen gas in onboard tanks, or it can be extracted from hydrogen rich sources such as natural gas, methanol, or even gasoline.
One of the benefits of this technology is the clean byproduct of the process used to create electricity. Only water and heat are produced in a fuel cell. Another benefit is the efficiency of the fuel cell itself, which can be twice as efficient in converting fuel to electrical energy as conventional combustion engines.
As is the case with hybrid cars, a fuel cell vehicle, or FCV, requires a high-output battery to store energy, a power control unit to manage the flow of electricity, and an electric motor. In addition, the vehicle requires a hydrogen fuel tank and a fuel cell stack, which is used to convert the hydrogen gas to electricity.
Right now, car manufacturers are dealing with several significant, and practical, barriers to the widespread use of fuel cell cars. These barriers include reducing manufacturing costs, improving performance, and safely storing the hydrogen fuel.
In a typical application, hydrogen gas needs to be stored in high pressure tanks located on the vehicle. Current technology allows for tanks that can only store enough hydrogen gas to allow the vehicle to travel 250 miles before refueling. Manufacturers are testing tanks that allow hydrogen to be pressurized in excess of the 500 p.s.i. limit of today's tanks. This allows more fuel to be stored in the tank, thereby extending the cruising range of these cars.
Fuels such as gasoline, methanol, or natural gas can also be used as the hydrogen source for fuel cell cars. However, removing the hydrogen from these fuels requires what's called a reformer. While reformers can extend the car's cruising range to 400 miles, they add to the complexity of the vehicle, and the reformers themselves require significant maintenance.
There are also safety considerations as well as distribution requirements that need to be addressed with this new technology. An extensive infrastructure to deliver gasoline to cars on the road today already exists. Storing hydrogen safely, and delivering it to consumers owning fuel cell cars, will take significant time, money, and public acceptance.
In 2017, there were only three car manufacturers offering fuel cell vehicles in limited numbers. Those cars include the Toyota Mirai, Honda Clarity and the Hyundai Tucson. Since each of these cars depends on hydrogen gas as the fuel source, availability is limited to those organizations with access to hydrogen refueling stations. As of March 2017, cars were only available where adequate refueling stations exist.
The following table compares the cruising range, vehicle class, motor and availability for each of these vehicles:
|2017 Toyota Mirai||2015 Hyundai Tucson||2017 Honda Clarity|
|Cruising Range||312 miles||265 miles||366 miles|
|Vehicle Class||Subcompact||Small SUV||Midsize|
|Power (kilowatts)||245 V NiMH||100 kW||130 kW|
|Availability||Sale or Lease||Lease Only||Sale or Lease|
On the one hand there are several significant hurdles faced by manufacturers of this new breed of car before their widespread availability and acceptance. On the other hand, there is the efficiency and environmental benefits these cars offer the marketplace. Over the next few years, the industry should have a better idea whether the benefits are enough to outweigh costs. If they do, Americans may all be driving a fuel cell car one day.
About the Author - Fuel Cell Cars