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| Thread ID: 26325 | 2002-10-24 11:39:00 | OT - Electricity from hot water | Mike (15) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 92612 | 2002-10-24 11:39:00 | Read it here Mike. :D |
Mike (15) | ||
| 92613 | 2002-10-24 17:32:00 | You can buy electrical device called "Peltier" that get hot on one side and cold on the other when current is passed, I suppose they just reverse engineered it, like a dynamic microphone is the reverse of a typical loudspeaker. Will it take off like the French car powered by compressed air? they say the biggest problem there is time taken to recharging the tanks, in that case why can't they just swap a tank for long distance travel. |
E.ric (351) | ||
| 92614 | 2002-10-24 20:25:00 | >>> in that case why can't they just swap a tank for long distance travel. Ever tried to lift a tank of compressed air? Just because it's "air" doesn't make it light :D Mike. |
Mike (15) | ||
| 92615 | 2002-10-25 02:55:00 | It's not the air that's heavy, it's the tank which holds it at very high pressure, Helium is the worst case ... a big cylinder holds about 4 lb of gas, and the cylinder weighs about 240 lb. That's one reason why helium was always expensive in NZ. It's still expensive, but is imported as liquid in a Dewar. A compressed air car will work. But the range will be ridiculously short. It's like battery cars ... Unless you can carry fuel, which contains a lot of energy per unit weight, you are wasting so much energy carrying energy. The idea of a borax compound which will carry hydrogen for a fuel cell looks the best idea yet. Seebeck was the one who found current produced with a temperature difference --- that's how thernocouples work for temperature measurement --- and he beat Peltier who found the opposite action. Seebeck generators have been built(a few, not popular because of the danger) which have been used for space applications. I've seen a couple of the remote weather stations which use them too. Unfortunately they use plutonium as thre heat source, and there's a certain amount of worry about what happens when the rocket blows up during the launch, or someone naughty pinches one of the weather stations. |
Graham L (2) | ||
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