Engineers Forum » Energy Producing Condensation Blimp

[Grant]

I have an idea for a blimp that generates energy from water condensing on the blimp and then flowing down a very long tentacle with a hydroelectric turbine at the bottom. The tentacle could be very long if you used composites.

The top the tentacle would need to be strong in tension in the longitudinal direction to prevent the tentacle from ripping away from the blimp. The bottom the tentacle would need to be strong in tension in the circumferential direction to prevent the water pressure from exploding the tentacle. The mathematical limit on the length of the tentacle is probably determined by the tensile strength of the material used.

I am not sure what kinds of condensation rates one can expect on the massive surface area of the blimp but I imagine some coatings can help it along. This blimp can follow clouds around and drip out a stream of water. There would probably be some very creative names for a blimp like this. If oil prices continue to rise this blimp might make economic sense

[RTH]

You would need lots of water mass coming off this blimp to drive a turbine consistently and a method to restrain blimp so it didn't float away from the fixed turbine generator on ground and a way to intercept clouds at various heights. You would also need to place the blimp in humid air and have the surface cool sufficiently to remove the heat of vaporization and condense into water. Does blimp cool down at night and just produce water power then? In daytime sun, the surface would heatup and not condense water. Might work in Florida but not in southwest with dry air. On a scale of ABC, I give it a C.
But good thinking.
Bob H

[Grant]

With some clarifications I think I can get at least a B-.

I was thinking the generator would hang from the tether so the blimp can chase humid air around at will. It could also oscillate between different altitudes to take advantage of temperature gradients. Maybe it would rise to cooler, higher altitudes and then fall into warmer, humid air. I am sure there are things that can be done to help encourage condensation on the blimp. It might make sense to use a fraction of the energy it generates to help encourage more condensation. It could also use the night and day cycles to its advantage by finding a way to cool its insides at night to help it create condensation on its belly throughout the day.

If you work in stages and use balloons and generators periodically on the tether there is no real limit on the length the tether can be. If the longitudinal tension got too great you could add more balloons periodically down the tether. If the circumferential tension got too high you could place a hydroelectric generator at that location to extract the potential energy, relieve the pressure, and send the water back down the tether to the next generator.

I know there isn't a huge amount of water flowing through this thing but the pressures could be immense.

[Grant]

I ran some numbers about how many kilowatt hours of energy can be extracted from a gallon of water a couple miles high. It isn't a whole lot. I'll take my "C" and consider myself lucky. It sure was a fun idea while it lasted

[Grant]

One other thought is that you could park the blimp just below a big cloud that was raining cats and dogs.