How the Horizon H-racer Works

Green Science Image Gallery The Horizon H-racer runs on hydrogen fuel. See more green science pictures.
Photo courtesy of Horizon

Hydrogen power has been on the drawing board for decades, and many carmakers have hydrogen-powered prototypes showcasing the eco-friendly technology. Hydrogen is, in theory, an ideal fuel source: It's the most abundant element on Earth; it generates power when it combines with readily available oxygen in the atmosphere; and the only byproducts of the reaction are water and heat [source: Lee].

Powering a large automobile with this type of clean-burning hydrogen fuel cell is problematic right now. There are issues to overcome surrounding hydrogen production and storage before we start seeing hydrogen vehicles on car lots. But powering a tiny automobile is apparently well within reach: A toy car called H-racer runs entirely on hydrogen fuel.


H-racer is an assemble-it-yourself model car kit much like any other model car kit, with one notable exception: Instead of running on disposable batteries, H-racer runs on renewable hydrogen. It has its own hydrogen fuel cell and itty-bitty hydrogen refueling station. All you put into the system make the car go is water.

From an educate-the-kids-about-alternative-energy standpoint, it's tough to beat a hydrogen-powered RC car (actually, only H-racer 2.0 has remote steering -- the original version does not). But considering how many batteries end up in U.S. landfills every year -- about 2.4 billion -- a toy car that doesn't need any is a not just an educational novelty [source: Ji]. It has actual ecological benefits.

So what's the H-racer all about? In this article, we'll check out what's going on under the hood, what the car can do with hydrogen, and what a hydrogen toy car might mean for the future of hydrogen power. Could a palm-sized RC car help usher in the age of full-size fuel-cell fleets?

We'll get back to where the H-racer fits in with the hydrogen movement in general. For now, first things first: How does hydrogen power the H-racer, and what can the little car do?

The H-racer connects to a refueling hose.
The H-racer connects to a refueling hose.
Photo courtesy of Horizon

The 6-inch-long (15-centimeter) H-racer is actually a lot like the kind of full-size hydrogen-powered car you'd find at an auto show. Inside is a PEM fuel cell, the type that powers cars like the Honda FCX Clarity concept (which is actually being driven by some lucky Californians).

A PEM (proton-exchange membrane) fuel cell is kind of like a battery. There's an anode (hydrogen), a cathode (oxygen), an ion-exchange barrier (the membrane), and a wire circuit that connects the anode and cathode so electrons have a place to flow. Hydrogen molecules in the anode react with a catalyst, breaking them into electrons and hydrogen protons. The electrons travel across the wire to the positively charged cathode, creating an electrical current, and the protons cross the proton-exchange membrane. Once in the cathode, the hydrogen protons and electrons react with atmospheric oxygen, creating water.

That's the basic process, anyway (see How Fuel Cells Work for a complete explanation). The big question is: Where does the hydrogen fuel come from? That's one of the obstacles to large-scale hydrogen power -- how to generate hydrogen gas cleanly and efficiently. In the H-racer, the feat is accomplished using water and electricity.

Solar electricity, to be exact.

Powering up the H-racer goes like this:

  1. Insert the refueling hose into H-racer's gas tank.
  2. Pour water into the hydrogen refueling station and activate the solar panel (if it's not sunny, you can still play -- just insert a couple of batteries).
  3. The solar panel generates an electric charge and applies it to the water, resulting in electrolysis. The water splits into hydrogen molecules (H2) and oxygen molecules (O).
  4. The refueling station releases the oxygen into the air and sends the hydrogen to the H-racer via the hose, where it enters the car's PEM fuel cell.
  5. In the fuel cell, the hydrogen generates an electrical current and recombines with oxygen from the air. The car releases the resulting water vapor.
  6. H-racer is ready to drive.

Using one tank of hydrogen, H-racer 2.0 can drive about 100 meters (328 feet) at approximately 25 meters per minute, which is faster than the original model thanks to a more efficient fuel cell [source: Arbor]. That gives you about four minutes of driving before you refuel. The fuel cell also powers the LEDs that give the car its neon glow.

Since refueling is pretty much the point with this particular model car, the four-minute tank isn't really a drawback. But it highlights some of the complex issues facing hydrogen implementation in real cars. A system this clean and simple doesn't exactly translate.

So does something like H-racer really affect the progress toward hydrogen-powered cars?

The H-racer glows in neon colors.
The H-racer glows in neon colors.
Photo courtesy of Horizon

Water electrolysis is basic science, and PEM fuel cells are nothing new. NASA's been using PEM fuel cells in space since at least the 1960s. If that alone were the solution to the energy crisis, we probably wouldn't be in a crisis in the first place.

But if a hydrogen-fueled auto industry is part of the solution to our current energy woes, then generating hydrogen power for a car the size of your hand is at least a step in the right direction. And while you can't just up-size the technology in H-racer and stick it in a Buick, it's probably a mistake to underestimate the value of an appealing toy that brings hydrogen power to the masses.

Horizon, the company that makes H-racer, is not a toy company. It's a hydrogen-power company that develops all types of fuel cells. H-racer is an attempt by the company to bring hydrogen power to the marketplace (and, perhaps, to make some extra cash while other, bigger applications are in development). The exposure and education value alone are a boon to the furtherance of a hydrogen agenda. Horizon has already sold tens of thousands of H-racers just in the United States, which means tens of thousands of kids and their parents are now able to use hydrogen power on a regular basis [source: Ji].

Are mass-produced automobiles and transit systems next? That's probably still at least a decade away, if not more [source: Ji]. But Horizon has other "in the meantime" plans besides H-racer: The company has shown off prototypes of fuel-cell powered motorbikes and golf carts, and plans to bring H-racer-type power to consumer electronics applications, like laptop batteries.

On the toy front, Horizon is also talking to major mainstream toy companies about incorporating its fuel cell into traditionally battery powered devices already popular with kids. If that happens, maybe hydrogen could become the next AA battery -- at least as far as kids are concerned.

For more information on H-racer, hydrogen power and related topics, look over the links on the next page.

Related HowStuffWorks Articles


  • "H-racer." Horizon Technologies.
  • "H-racer 2.0." Horizon Technologies.
  • "H-racer 2.0." NADA Scientific.
  • "Hydrogen Fuel-Cell Runs Toy Car." Wired. July 23, 2006.
  • Ji, Xiang. "The Fuel-Cell Car -- for Kids." BusinessWeek. July 16, 2007.
  • Lee, Evelyn. "H-RACER: Hydrogen Fuel Toy Car." Oct. 11, 2006.
  • Maas, Franz. "H-racer and Hydrogen Station." Franz Maas Weblog. Dec.15, 2006.