To overcome the problem of distribution infrastructure, why not build small hydrogen extraction device?

Question

I'm thinking about a unit small enough to be in or near your garage. Sort of a "personal hydrogen plant" that would only need to produce enough for one family's use. It might be powered by solar or wind making it cost effective even if the initial investment were fairly high. Anybody seen anything like this being developed?

Answer 1

Besides the economy of scale problem with a home-sized unit, you've got the obvious problem of what to do with the hydrogen once you've created it. I assume you're planning to use electricity to split water (I make this assumption based upon your use of solar or wind as your power source). Be aware that it takes a great deal of electrical energy to accomplish this.

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In fact, the rest of my answer is moot -- Based upon the fact that you've already generated the electricity, you'd have a FAR more efficient system by storing and using the electricity directly without going through the cracking conversion to hydrogen! So while the idea is "interesting", it's not efficient. Systems like that by Honda (below) have *large* energy losses associated with their hydrogen production. Storing the power initially generated would make more sense. Heck, generate enough electricity with your wind/solar and you can sell any overage to the grid!

Note: NO one believes an efficiency of greater than 40% is physically possible for solar->hydrogen generation (***best current technology has it at around 13%***). For most purposes, direct electrical storage makes a great deal more sense. There would have to be some major overriding reason to employ hydrogen instead of stored electrical energy for this type of design to be of value.
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Hydrogen gas isn't dense enough to be useful. You'll need to compress it in order to develop enough pressure to store and use it for home heat, and would need to chill it enough to use to fill a tank to run an automobile (you'd be better deriving your hydrogen from a fuel cell for the latter). Both of these take a fair bit of electricity to accomplish. Big efficiency problem. More energy used than created. Again, you're better off storing and using the electricity that you started with.

There are the obvious technology related safety issues in the production and pressurization of hydrogen that make it an unlikely candidate for "home use" at this time.

Answer 2

I first saw a similar idea at the Knoxville Worlds fair in the early 80's. For was introducing the Probe as a concept car with a natural gas variant. The car could be refuled using a natural gas compressor overnight. The demo compressor package shown with the car at the fair was about 3 ftx2ftx2ft in size.

Residential recharging stations are available (see link) .

Using Natural gas would prove far more cost effective than generating hydrogen on site. Although the existing Natural gas inferstructure could easly distribute hydrogen and/or methane. I was think that it would be easier to incorporate methane from landfill sites easily into a natural gas distribution system with the idea of augmenting and not totaly replacing natural gas.

Answer 3

There are several that have been proposed and prototyped. They are being considered by companies in the energy field. One uses aluminum scrap and the addition of strong sodium hydroxide (lye) to generate oxygen. The other newer idea uses aluminum with gallium that will not oxidize on the surface and so can give off hydrogen by simple water addition. They are small enough to fit in a car and generate oxygen there.

Answer 4

I saw this article on the topic...
http://www.sciencenews.org/articles/20000916/fob6.asp

Answer 5

http://world.honda.com/FuelCell/FCX/station/

Honda has a prototype