Not Really Free Energy from Silicon and Water

Jan 28 2013 Published by under Physics

A reader sent me a link to an article about a new technique for producing hydrogen. His original request was for me to debunk it, because it looked like another free energy scam. But it isn't, so I'm going to attempt to explain why.

BUFFALO, N.Y. — Super-small particles of silicon react with water to produce hydrogen almost instantaneously, according to University at Buffalo researchers.

In a series of experiments, the scientists created spherical silicon particles about 10 nanometers in diameter. When combined with water, these particles reacted to form silicic acid (a nontoxic byproduct) and hydrogen — a potential source of energy for fuel cells.

The reaction didn’t require any light, heat or electricity, and also created hydrogen about 150 times faster than similar reactions using silicon particles 100 nanometers wide, and 1,000 times faster than bulk silicon, according to the study.

Producing hydrogen from water, with no light, heat, or electricity! I can't blame you if you read that, and think that it sounds like a free-energy scam. We're talking about producing hydrogen from water without using any energy!

But here's the catch: it's a chemical reaction. It consumes the silicon, producing silicic acid.

There are all sorts of chemical reactions that can release energy. That's why we like gasoline so much: it's a chemical that reacts easily with oxygen, and releases lots of energy when it does. There's no cheating going on there. As thermodynamics predicts, everything trends towards the lowest energy state - if you look at the thermodynamic system containing a reaction that releases energy, it properly ends up in a lower energy state.

In the case of this silicon bead technique, all that we're seeing is a typical entropy increasing chemical reaction.

If the silicon wasn't consumed by the reaction, but we were still able to break water molecules producing free hydrogen, which we could then burn to produce energy, that would be a free energy system: you could take water, dump in the silicon, produce hydrogen, burn the hydrogen, releasing energy and producing water, and then take the resulting water, and dump it back into the silicon mixture. But that's not what's going on here. Instead, the silicon is getting consumed, and if you wanted to re-use it, you would need to use energy to extract it from the silicic acid - which would be a typical lossy thermodynamic process.

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  • bardbloom says:

    Pity. I initially hoped you were talking about artificial leaves -- silicon devices which you put in water and expose to sunlight, and they break the water into hydrogen and oxygen. No violation of thermodynamics or consumption of silicon there, just a clever use of sunlight. And by "clever" I mean "plants have been doing this since forever."

  • Mu says:

    These are for low weight low output power devices like fuel cells. If you need 200 W continuous to power a radio in the field, you can carry 5 m^2 of solar cells (with 5 kg of batteries and inverter for nighttime), 1kg of batteries per day, or a 2 kg fuel cell and 50 g of silicon powder per day.