You may have heard that major auto manufacturers such as Toyota, Honda and GM are starting to make hydrogen fuel vehicles for production, and not just as experiments. This could spell the end of the hybrid fuel vehicles or it could be just another failed attempt to get us off of fossil fuels. But there’s something interesting about hydrogen as a fuel source: it’s not technically a fuel.
Hydrogen does not exist in nature in any appreciable quantities. We can’t mine it or harvest it: we have to create it. And the way we create it is through a process known as a electrolysis. No, this isn’t the zapping of unwanted body hair, instead it’s a very simple electrochemical reaction where DC current is applied to water, and the water breaks down into its constituent components, H2, diatomic hydrogen, and O, oxygen. This is something you can do at home, or may have done in school chemistry class. But there’s one thing that’s always true about this reaction: it takes more energy to create the hydrogen than the hydrogen will give off.
Fossil fuels are very dense energy stores, and they store energy that ultimately came from the sun, in some cases millions of years ago. And while it’s true that the sun gave more energy than we can get out of fossil fuels, WE, that is humans, don’t have to put very much energy into the equation in comparison to the energy we can extract. With hydrogen, we have to put in ALL the energy we can extract, and then some. Energy is always lost when hydrogen is created and used as fuel. Because of this, it’s best to think of hydrogen as an energy conveyance medium rather than a fuel. It’s a bit like a battery made of gas, in practical terms.
But that doesn’t mean hydrogen powered cars are a bad idea. Though it is extremely flammable, and thus dangerous (see airship Hindeburg), so is gasoline. And unlike gasoline, burning hydrogen whether directly or in a fuel cell, produces only one “waste” component, and that is – you can figure it out – water, or most likely water vapor. It would even be possible to store this water in the vehicle and use it for cooling or windshield washing. Hydrogen fuel cell have been used for decades on human-inhabited spacecraft for this reason.
There’s a lot of debate over the so-called “hydrogen economy” and we’ll leave that to experts.
You may or may not be driving a hydrogen powered car in a few years. But one things for certain: if hydrogen powered cars hit the mass market, it won’t be long for someone installs a device that shoots flames into the air. Count on it.