Simple Device Invented in 1833 May Lead to Cheap Hydrogen
A modern team of Italian researchers has uncovered a device invented by fellow Italian G.D. Botto in 1833 that can be used to generate hydrogen with inexpensive, everyday parts. By reflecting sunlight from two parabolic mirrors onto a hollow tube wrapped in metal and filled with water, the device generates enough electricity to produce hydrogen through electrolysis. Theoretically, the device is so simple that anybody could build it in their garage.
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In the original Botto device, alternating links of platinum and iron were connected in a chain that was then wrapped around a wooden rod. By heating one side of the rod with a flame, Botto was able to generate an electric current in the chain through thermocoupling of the two metals.
Botto’s original intent was to simply show that he could produce electricity using a thermocouple of two metals. Making hydrogen bubbles in water through electrolysis was his way of visually confirming an electric current was present. But, after uncovering the original Botto work, the modern Italian team realized the device had a different kind of potential in today’s energy-dependent world: a cheap way to make hydrogen without advanced manufacturing techniques using off-the-shelf components.
With some modern thinking, the Italian team was able to modify Botto’s device in rather ingenious ways. Firstly, they replaced the flame that Botto used to produce heat with parabolic mirrors to concentrate the sun’s rays on the tube. Secondly, they replaced the rather expensive platinum metal with copper. And thirdly, in order to create a greater temperature difference between the heated side of the tube and the cool side of the tube (greater temperature difference equals larger current), they ran water through the center of it.
The researchers estimate that, although the power output for their experimental device is small (only about 20 mW), it could generate enough current to produce hydrogen gas through electrolysis of water. Given that the device is scalable, I’m guessing it would simply be a matter of daisy chaining enough of them together to generate the required amount of hydrogen.
The researchers also suggest that rather than using a thermocouple of two metals, it would be more efficient to use a thermoelectric semiconductor to obtain a much higher power output. I’m just waiting for them to release a design on the internet so that we can all start experimenting with hydrogen production.
Image Credit: De Luca, R.; Ganci, S.; and Zozzaro, P. “Revisiting an idea of G D Botto: a solar thermoelectric generator.” Eur. J. Phys. 29 (2008) 1295-1300.
Source: PhysOrg.com
The only use of this comparatively inefficient device would be for countries that have no contact with the outside world yet have all of the resources needed to build this. However, why not just build a simple thermal solar system and run a steam generator? If you can make a metal thermocouple you surely can make a simple wire wound electrical generator. It’s sure to be many more times more efficient at converting the sun into electricity.
This is a fun science experiment at best until we are shown the efficiency and cost numbers. I expect them to be uncompetitive compared to even other proven and extremely simple systems.
Nate hit it right on the head. Hydrogen is an energy sucker. Just produce energy, not Hydrogen! LOL
If I’m going to pick on anything in this article it would have to be the headline. You have deliberately sensationalised a dull and uninteresting event in a shameless attempt to draw more readers to your website.
What actually happened here was a couple of scientists were looking through some old papers with today’s green perspective. They saw something mildly interesting and speculated whether it could be adapted to be useful by today’s standards. That’s not worthy of the headline you gave it.
Actually, I’m going to pick on another bit of the article. 20mW is not just small. It’s minuscule. Scientists and engineers are known for understating things in conversational articles. It’s important that you understand this when reading articles written by scientists.
To illustrate just how small 20mW is, we receive roughly 1KW of energy from the sun per square metre. In order to capture 20mW of electricity using conventional solar panels at 20% efficiency you would need a single solar panel that was 3mm x 3mm. There is no indication of how large this device is but I’m guessing that it is larger than 3mm x 3mm. If we’re generous and call it 10cm x 10cm then it has an efficiency of 0.2%. Daisy chaining enough of them together would cover the earth several times over which is somewhat impractical.
When the scientist summed up at the end of the PhysOrg article, the main point he was making is that we should be getting energy directly from the sun, not that this device was the one that was going to make that goal feasible.
That’s awesome. It might be time to start digging into older scientific archives of everything to see if inventions can be rediscovered with a modern approach to help make the world better.
nice device great post
This is just dumb!
Thermocouples are expensive and inefficient. Replacing them with standard high power density solar cells would produce several times more power from the same solar collector setup.
H2 is a valuable fuel-cellable gas! Gimme enough of it during the day from a home-brew generator, I could keep my wrinlkled old butt warm at night - for free, off-line by my Post (GRD) great republican depression humanure and compost fed veggie garden! G d is good to provide such amazing secrets to the uber-slothful, sinful and immoral American people! I wonder how large a bank of gadgets like this it takes to provide a practical, usable amount of H2 gas? The fuel price, solar, is free, now what? Maybe some Chinese engineering student can figure it out instead of going to a beer bash, football game, cruise in his sports car or having a sexual interlude with his bitch, or filling out Microsoft applications like the American boys, and we can get some answers? Seems to me going from Solar to H2 in one step might fit many useful circumstances.