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first the TFA is wrong. the goal is to cut the weight by only a factor of 2.
http://www.dod.mil/ddre/prize/rules_doc.html

from the DOD site:
"Demonstrate a wearable electric power system providing 96 hours of equipment operation at less than half the current weight. The power system should attach to a garment (vest) and provide 20W average electric power for 96 hours with peak power requirements of up to 200W for short periods. All components, including the generation, storage, electronics, and connections must weigh 4kg or less, including the attachment system. The total minimum energy required is 1920 W-hr (20W * 96hr)."

The call is incredibly poorly worded but it appears the current weight is 9Kg (about 20 pound, not the 40 pounds states in the article linked to)

1920 W-hr is about 6 MJoules and if we assume that means 4.5 KG then that's 1.5MJ/Kg.

currently Mg-hydride (with Li) gets over 8Mj/Kg. So you could win this contest right now using those, assuming the pulse-power requirments are achievable.
http://www.energyadvocate.com/fw64.htm

  to put this in perspective, as to what is ultimately possible to achieve in a quasi theoretical limit: Gasoline holds about 44 Mjoules / Kg. So a perfect electrical conversion from gasoline would be only 5 fold more than what is available now.

Ok AC, I'll bite.

Yes, I did read the article. And no, I haven't read everything else in this thread. I'm responding to one post, not an entire thread.

If you'll read my post, I didn't say that hydrogen wasn't a problem. What I did say was that "hydrogen was not the only reason". I still stand by that. Wikipedia articles tend to present all sides of an argument, so you'll find points both pro and counter in most any article there.

What I get sick of are people hearing about hydrogen cars and going "OMG you're gonna blow up like the Hindenburg!!!11one11!!", and never once realizing that they were sitting on maybe 12 gallons of gasoline all the way to work, which has the explosive potential of two-fifths of a ton of TNT. No kidding.

The fellow you replied to may have been talking about corn-based ethanol. What you may not know is that those folks at Archer Daniels Midland who make the ethanol in American gasoline 18.9 MJ of energy per kilogram of ethanol produced. See, it costs more (in energy) to farm and distill that ethanol than you get back out of it. It's a black hole. It's a stupid idea.

'Course, this is only because we subsidize corn so much in this country. The Brazilians use sugarcane, which can be farmed much more energy-efficiently, and which is why the Brazilians are now laughing their asses off at the Americans.

(See, Brazil has cut back enormously on the quantity of petroleum it imports. America hasn't. Yeah, this is what we should have had, if we'd responded to the 1970s oil crisis in a more sensible way. Now we're acting surprised and pretending no one could have seen this coming. Pfah.)

--grendel drago

check out this

What this tells me that the manufacturers are idiots and we can improve it.

If we're not even close to producing one that is 59% efficient why wouldn't something like this help improve it. From my thinking it would help in several ways:

1) These turbines are designed for everyday use which means that they have to be cheap and replaceable as they die.
2) They produce 3 - 4 watts per device. This is not insignificant in larger numbers. How many rivets do you see on large buildings?
3) By breaking up the wind collection into smaller pieces it's possible - at least I think it is - to help increase the efficiency of the energy production due to more even losses due to friction, faster initial generation time, etc.
4) These things are small enough that they can be placed almost anywhere . I can easily see these being placed on the outside of the tops of large buildings to suppliment power.

I think these things are more important as devices per-se than just cell-phone rechargers.

check out this

I remember some time ago seeing a documentary by James Burke written as a retrospective (in 2050) on global warming. A pretty good (and very critical) synopsis of the show is here.

I recall him mentioning something about how the polar ice would melt, diluting some kind of salt/mineral/whatever transport stream in the atlantic, and effectively killing off the ability of the oceans to simultaneously absorb CO2 and somehow effect some atmospheric flow (the jet stream, perhaps?)

As the above critique points out, though, even that was perceived to be approximately a 70 year cycle and couldn't explain global ice ages or anything really apocalyptic.

Perhaps we should start digging tunnels now to prevent any mine shaft gap.

First, we don't really know where oil comes from.

This is "science" that is only meant for political posturing. By his theories, coal is a better source of energy because it took less plant matter to make it.

"After the last deep ice age, (about 10,720 years ago) an enormous lake (Lake Agassiz) remaining from melting glaciers in central Canada burst through, and dumped an enormous quantity of water through the St. Lawrence River and out into the north Atlantic. This fresh water diluted the Gulf Stream and literally stopped it, because the diluted water was not dense enough to sink. All of this took place in a short period of some 70 years. The effect was to chill the northern regions considerably; in fact, the event was discovered only because seeds of some Canadian flowers that favor extreme cold were found in abundance in the Antarctic ice formed at the time. It was well after the ice age was supposed to be over."
- Burke's delusion: After the Warming

Burke then goes on to say that we are currently having the same drastic effect on the environment today with our polution and pumping out greenhouse gasses way too fast for the environement to cope. His prediction, is that global warming is going to come upon us hard here soon. Unfortunately, he leaves this same scenario out to off-set global warming. This makes his presentation somewhat lacking. However, I found his video-essay very enjoyable anyways. And yes, this is the same James Burke that did the 'Connections' series you may have seen on the Learning Channel.

• Other James Burke Information
• Palmer's James Burke Fan Companion
• Connections Summaries