Microbes Pass Valuable Gas

inimicus writes "Wired reports: 'With a reliable source of hydrogen, fuel cells can produce energy with water as the only byproduct.' The good news is that there's a functional prototype (measuring 0.7 square centimeters and less than 1 millimeter thick) that produces 1 microwatt of power -- approximately enough to power a digital wristwatch. Personally, I'm intrigued by the concept of powering my laptop with sugar-water..."

Comments

Hydrogen balooney

[Muhammar]

"a 53-cubic-foot reaction chamber would provide enough hydrogen to run a 200-kilowatt fuel cell and supply energy for about 20 houses"

1. I do not believe that they can produce that much hydrogen from this much volume - maybe she is talking about the peak output her 15 liter tank, multiplied by the factor to get to 200kW "to power 20 houses".

2. 10kW per house is actualy very little - this is another example of "data massage". Average hair dryer takes about 2kW, so does ironing your shirt or vacuum your room. I am not talkig about things like electric laundry dryer or A/C. I *lived* in place which had 20Amp circuit brakers (which gives 20kW at 120V), and the circuit brakers were out all the time. We had an electric heater, but neither A/C nor laundry in the apartment.

3.Running fermentor is not the easiest thing to do - you have to keep the microbes happy - the output can vary, there can be problems with contamination (some mold gets in which wipes out the bacterias over time) etc. And they smell bad.

4. Using a fermentation tank to power laptop is pure unmitigated balooney - here the power source can be more expensive than with household source. With laptop, the premium is on weight+size. Much more compact and fairly affordable source of hydrogen for laptops can be sodium borohydride: this is a common industrial chemical, water-stable and 40g of the stuff + 40g of water produces 8g of hydrogen, which is one of the best weight ratios with nonelectrolytic sources of H2.

5. Enviro-technologies development: most of the time it's a confederacy of shabby science, political pressure and populism. The surest way to protect enviroment is to find a different job for pop-science enviromentalist - preferably in gender studies or postmodernist deconstruction university departments.

Re:Hydrogen balooney

[barakn]

Average hair dryer takes about 2kW, so does ironing your shirt or vacuum your room.

And I suppose you iron your shirt 24 hours a day. I just calculated a thirteen month average of my home's electrical usage (data straight from the power bill), and it comes out to 0.765 kW. The two of us use a 25 year old refrigerator, an electric hot water heater, electric stove, '80s vintage dishwasher, clothes washer and dryer, and limited electric baseboard heating and a space heater during the winter. Oh, yeah, and the computer, tv, stereo.....and lights. And a 24/7 fan to eliminate radon. And the iron and vacuum

I *lived* in place which had 20Amp circuit brakers (which gives 20kW at 120V), and the circuit brakers were out all the time.

Your electrical system's inability to handle peak usage says nothing about average usage.

Water Vapour Greenhouse Gas?

[DeadVulcan]

I often hear people touting hydrogen because the only by-product is water, which sounds wonderful... However, I suspect that's only because we can drink the stuff.

But isn't water vapour the most potent greenhouse agent in our atmosphere?

Not sure, just asking.

One must also ask how much water vapour is currently in the atmosphere, and how much would be added by large numbers of hydrogen-driven power plants. Again, I don't know. Anyone know of any research on this question?