Slashdot Mirror
Laptop Fuel Cells Coming Soon
tomsastroblog writes "Soon laptop batteries could last all day and be recharged from a cartridge. BBC News has a piece on fuel cells as laptop batteries, and what their adoption could mean for laptop usage." From the article: "At the Cebit technology fair in Hanover, Taiwanese hi-tech firm Antig said its fuel cells should be on the shelves of computer shops by early 2007. The first versions of the methanol-using units should keep a laptop going for up to nine hours. Fuel cell technology got a boost recently when international air flight regulators changed rules that banned passengers from carrying flammable methanol onto aircraft."
http://hardware.slashdot.org/article.pl?sid=06/03/ 03/0134241
There is a German company (http://www.smartfuelcell.de/ that is already producing fuel-cell powered generators for camping. I guess it won't take too long until they are small enough to fit in a laptop bag.
where's all that Karma?
Laptop fuel cartrages mean new DRM and propriatary designs as well as messy (and dangerous) 3rd party refil kits.
A lot of people keep saying this, but it just doesn't hold true!
First of all, methanol doesn't pose nearly the health risk most people believe. As someone with a solid non-practitioner background in both chemistry and pharmacology, I would play with methanol over toner or ink any day... Additionally, the breakdown products the the electrolyte in Li-ion batteries makes methanol exposure look like a cool drink of mountain water by comparison (for an idea, the most common counts as a chemical WMD in a different context).
Second, methanol doesn't pose nearly the fire/explosion risk most people believe. The Li-ion batteries we use now pose a FAR greater risk of explosion, and as for fire, if you take the same precautions you would when refueling your car (with yet another far more flamable/explosive liquid), you have nothing to worry about.
Third, refilling... Aside from the previously-mentioned toxicity of ink and toner, methanol evaporates cleanly. So if you spill a few drops, you can just let them evaporate rather than permanantly staining yourself, your table, your laptop, your carpet, your dog, and seemingly anything else even in sight of the ink refill kit.
The biggest complaint about the idea of using fuel cells over a rechargeable battery in laptops comes from the UPS-factor. Even an all-but-dead laptop battery will let it stay up (assuming you have it on AC) through a short power outage, or to move to another outlet, or to quickly reinsert the plug your cat pulled out, etc. Running on a fuel cell, all those advantages disappear unless you use the fuel cell as your primary power source, which could get expensive over time (despite methanol's low cost, AC power costs a hell of a lot less).
The reason fuel cells are much hyped, and preferred over batteries is that they use liquids to produce the electricity. This means that the size of the reaction interface is decoupled from the energy storage medium (whereas in a battery, they are intimately linked [normally]).
So, the size of the reaction interface determines the power that you can get out of the fuel cell, and the size of the energy reservoir determines how long it will last.
A laptop draws, what, 100 watts peak? A car with an 80 hp engine is at 60 kW - 600 times more. A fuel cell big enough to power that would be prohibitive in cost. Not to mention, the fuel cell will degrade with time - impurities in the fuel, and (if it's a polymer cell), degradation in the polymer itself.
Next point is the fuel medium. The energy density of methanol is less than gasoline, at about 22MJ/kg vs 45MJ/kg for gasoline. So, assuming comparable fuel efficency with the internal combustion + mechanical drive vs fuel cell + motors, you'd need twice as much fuel.
There are no good fuel cells that operate on gasoline - the more complex the hydrocarbon, the harder it is to build a fuel cell. Couple that with the way the sulpher tends to kill fuel cells, and it's not feasable (low sulpher gasoline is available - have you ever seen guarenteed no sulpher gasoline?)
So, it would cost more, and you'd only get half the distance on a single tank of methanol. Assuming that you can get the methanol. The whole fuel distribution problem is a seperate case.
All the numbers here are conservative - I'm sure my powerbook draws significantly less than 100W, 80 hp is at the low end for a car - I believe 100hp is more typical. The laptop fuel cells don't use pure methanol, it's methanol and water, further reducing the energy density.