Jones wrote: > I have often wondered about using the massive cooling towers of nuclear > power plants to move large amounts of electric charge a few hundred feet > apart, which requires work - (which is essentially 'free' due to the > buoyancy of waste heat in the water vapor).
> By collecting the additional energy in a wire grid at the top of the > tower, if that could be done - then it might be possible to get net > 'free energy' from the waste heat. Typically such plants must expel > twice the net heat energy of the grid electrical equivalent going out. > IOW a gigawatt(electric) plant would expel upwards to 2 gigawatts of low > grade heat in the form of warm water vapor, through these towers. If one > could convert this into electricity at 5% efficiency, then the system > required to do that would easily have a market value (worth) of ~10% of > the cost of the nuclear plant itself ! which would amount to hundreds of > millions of dollars. A huge win-win situation for any inventor. Jones, I think you're onto something, your "Night Shift" tendencies notwithstanding. The configuration would have to be a little different,I believe,than what you propose. One problem is that electrets really aren't very good. Much better and easier to make is simply charging up an insulator against a grounded conductor with a high voltage source, i.e., a one plate capacitor with a dielectric. These hold a charge for a remarkably long time and can store a lot more coulombs than an electret. Besides, electrets aren't so permanent either. Naturally, the single plate capacitor's charge is easily replenished when necessary. Instead of using pointed emitters to tranfer the electrons or "holes" to the water vapor, you would want to have the water vapor transported in close proximity to a grounded conductor and the charged dielectric. This would charge the water vapor by induction rather than corona discharge. In other words, it would be a continuous electrophorus with the work being provided by the tremendous waste heat emitted from the reactor. As you point out, this may be a way around M. Carnot since it's not really a heat engine per se. As the water vapor rises from the area where the induction charging takes place, the voltage would rise in a fashion similar to a Van de Graaff generator and the electric charges could be collected quite easily. M. _______________________________________________ Join Excite! - http://www.excite.com The most personalized portal on the Web!
