Run Your Car on Water! (No, Not Really)

The other day, I came across a pseudoscience site so laughably ridiculous I just had to share it:

(Warning: Page has sound.)

As the URL indicates, the unknown people behind this site are selling a kit which they claim will enable you to turn your car into a “water-burning hybrid” that can use ordinary tap water as a fuel source. I’ll go over the mechanics of why this is impossible in a minute, but first, I want to call attention to this curious claim:

You can run your car on water, supplemental to gasoline, to increase your car’s fuel efficiency and reduce your fuel costs significantly.

Supplemental to gasoline, not as a replacement for it. The site elsewhere claims that this technology allows you to save “over 40%” on fuel costs. Now, if you think about this, why would it be only 40%? Either water works as a fuel source or it doesn’t, and if it does, then why can’t you rely on it exclusively? Why can’t you make a car that runs entirely on water and doesn’t use any gas at all?

In any case, the site has an explanation of how this technology is claimed to work:

Our easy conversion guide will show you how to use electricity from your car’s battery to separate water into a gas called HHO (2 Hydrogen + 1 Oxygen). HHO, also called Brown’s Gas or Hydroxy, burns smoothly and provides significant energy – while the end product is just H2O!

Clearly, the proprietors of this site are banking on their readers not knowing the laws of thermodynamics. Yes, water can be electrolyzed into hydrogen and oxygen gas; and yes, those gases can be burned and will recombine into water. The inconvenient fact that this ad leaves out is that each step of this process necessarily involves a loss of energy. This technology “works” only in the same way as a businessman who loses money on every sale but thinks he can make up for it on volume.

The problem is that water, unlike natural gas or petroleum, is a highly stable compound. The chemical reaction that turns hydrogen and oxygen into water is said to be thermodynamically irreversible – that is, under natural conditions, it runs only in one direction. To put it another way, it takes more energy to break water into its component elements than you get by putting those elements back together. You certainly can use an external source of energy, such as a car battery, to break water down into hydrogen and oxygen; but the process of burning those gases will inevitably release less energy than it took to break the water down in the first place. Therefore, if this technology operates as described, it not only will not increase the mileage of your car, it will actually decrease it!

The description quoted above – “use electricity… to separate water” into Brown’s Gas, and then burning the Brown’s Gas, which “provides significant energy” – sounds suspiciously like a perpetual motion machine. Another excerpt confirms that that is what this site is claiming:

Your car will become at least 40% more fuel efficient…

The only way this could make your car more fuel efficient is if burning the Brown’s Gas produced more energy than it takes to extract it from water, and if that were the case, this cycle could be repeated indefinitely. If this technology worked as its vendors claim, it would produce unlimited energy for free. Anyone who chooses to believe that this is possible is joining the long line of perpetual-motion devotees who’ve bet against the first law of thermodynamics. And, as noted physicist and skeptic Robert Park points out in his book Voodoo Science, no one has ever won that wager.

That said, there is a plausible, non-crackpot scheme for using water as a fuel. That technology is called nuclear fusion. With a working fusion reactor, such as the one the ITER consortium is currently building, it’s theoretically possible to extract hydrogen from water and then, under extremely high temperatures, fuse that hydrogen into helium. But this, too, is a thermodynamically irreversible reaction, and more importantly, it’s a nuclear reaction. It in no way resembles the crackpot pseudoscience of splitting water into hydrogen and oxygen, then recombining those gases into water and somehow ending up with more energy than you started with.

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About Adam Lee

Adam Lee is an atheist writer and speaker living in New York City. His new novel, Arc of Fire, is available in paperback and e-book. Read his full bio, or follow him on Twitter.