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Water-powered gadgets - cheap tricks or real inventions?
September 21, 2007

So I was browsing the web the other day and came across a water powered clock. The description claimed that the clock’s “internal converter simply extracts electrons from water molecules… acting as a fuel cell to generate power…” Sweet! Water as a fuel? How did I miss this amazing development? Further surfing turned up a plethora of other water powered gadgets, from calculators to cars. Just add water and go! But is it that simple?

Of course the answer is no. Take the water powered clock. Extract electrons from water molecules? Last I checked, water liked to hold on to its electrons. So just how does this gadget work? It runs on the same principles as an ordinary battery, using metal electrodes and water as the electrolyte. You can construct a similar battery by sticking a penny and a nail in a potato (here the potato takes the place of the water as the electrolyte). These types of batteries, while certainly more environmentally friendly than your standard Duracell, are limited to very low power applications. Or are they? Turns out a water activated battery technology has been developed in Japan that uses carbon based compounds and that can produce the same amount of energy per kg as a normal battery. And because they are made of abundant carbon instead of processed metals they have the potential of being cheaper, non-toxic, and taking less energy to produce.

But what about the water powered car? I came across a video which makes it look like water powered cars (and indeed water powered everything) are right around the corner. But when you strip away the hype all you are left with is a car that increases combustion efficiency by burning a form of Brown’s gas – a mixture of hydrogen and oxygen. As with hydrogen fuel cells, the byproduct of this reaction is water – making it an entirely clean process. But also as with hydrogen fuel cells, the real problem is where to get the hydrogen. It takes more energy to split apart the hydrogen and oxygen atoms of water than you get when you recombine them, so the idea of having a car where you put water into the gas tank, split the water apart to form hydrogen and oxygen, then recombine them via combustion or a fuel cell, is totally infeasible. The only way to make this process totally green is to use some sort of renewable energy source – solar or wind, for example – for electrolysis (splitting apart the hydrogen and oxygen atoms in water), and then using the resulting hydrogen as a fuel. Until we have the infrastructure in place, pipe dreams like the water powered car will remain YouTube video fodder.

Sean, gearhead at large

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*water clock picture courtesy of www.Thinkgeek.com and potato battery courtesy of www.pbskids.org

Copyright 2007 Organicpicks