Almost Free Electricity

Packer said:
If you launched at the top over the chimney the breeze will act like a thermal and you’ll go higher until it plays out. If you launched outside, gravity will take you lower.
Click to expand...
Incorrect.

There will be no breeze/updraft inside the chimney. Why would a column of air enclosed by a chimney but open at the top and bottom behave any differently to a column of air next to it that is not enclosed?

What mechanism is causing the chimney to use the pressure differential between top and bottom to generate a breeze that is not happening outside the chimney, where there is exactly the same pressure differential?
 
scudsucker said:
Incorrect.

There will be no breeze/updraft inside the chimney. Why would a column of air enclosed by a chimney but open at the top and bottom behave any differently to a column of air next to it that is not enclosed?
Click to expand...
Elves
 
Packer said:
That's why the hill. If you stand at the top of a building by an open lift shaft it acts as a chimney. You can feel a breeze as ²higher pressure air at the bottom seeks equilibrium with the lower pressure air at your level.
Click to expand...
No, I think you misunderstand.

The reason you feel air moving up an elevator shaft is because of a pressure differential created not by altitude, but by moving air. Same as lift on a wing.

Air (wind) at the top of the building is moving faster than air (wind) at the base of the building. This creates a pressure differential which reaults in air moving up the shaft - just like lift a wing.

This can also be easily measured, the bigger the difference in airspeed between the top an bottom of the building the faster air will move op the shaft.

So congratulations, you have proposed we build a very overly complicated wind turbine.
 
SauRoNZA said:
But that’s based on heat, not air magically moving by itself.

Quite different.
Click to expand...
In any tall chimney there is always going to be a temperature differential between the air at the bottom and the top which produces the stack effect. Several prototypes have already been built although no commercial plants have been constructed as yet.
 
Jake45 said:
... no commercial plants have been constructed as yet.
Click to expand...
For a "technology" as old as tents (as I understand it they do these in deserts to get cool air in..) no commercial construction yet...
As others have said, wind = wind turbine, solar heat, you may as well use nice cheap PV!

If you're bothering to build a big tower just stick a big turbine at the top and use the already fast flowing air up at the top!
 
Jake45 said:
In any tall chimney there is always going to be a temperature differential between the air at the bottom and the top which produces the stack effect. Several prototypes have already been built although no commercial plants have been constructed as yet.
Click to expand...

Your links are not about a minor (natural) differential though.

They are forcing heat into the bottom to make it work.

OP expects it to magically work all by itself without any external intervention.

Also anyone can make a prototype of anything, doesn’t really mean much unless it works.

This part is rather amusing.

95e7740ef3496add770ced8c428a2479.jpg


But regardless of that, your very link illustrates the effect is due to temperature and moisture differences (hence the need to feed it hot air) and has nothing to do with air pressure as the OP suggests.

Therefore it can’t be “free” and unlimited as it’s not self sustaining.

The greater the thermal difference and the height of the structure, the greater the buoyancy force, and thus the stack effect.
Click to expand...
 
Last edited:
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X