A question of curiosity

[GeeMac]

I am curious to know if anyone has ever tried to run more than one mill on a tower? One at the top and the other twenty feet under it?

[Flux]

Probably! nearly every conceivable thing has been tried over the last 100 years. I think that there have been ideas for many rotors arranged like a tree on one big tower.

The fact that it is not general practice makes me think that the snags outweigh the advantage.

Flux

[Devo]

I was going to do this very thing but decided not to on my first tower, you would need good guy wires & extra anchor weight.

I was going to build a model tower going 1 centimeter every foot of the actual tower to find out how much room was between the guy wires & make a pipe similar to dans "clamping" pipe for extra mill tower that would swivel on top of one bolted tight.

Grease would be a major concern as after time a weak spot would form from the lower mill wearing the tower & it could break part way up.

A plastic or light metal bushing could cure this.

Maybe next year I'll give it a go, hopefully someone will do it first & I can copy..  :-)

Devo

[spinningmagnets]

I recall seeing a pic of a tower that had a conventional DanB style prop at the top about 60ft up and then halfway up the tower was a VAWT. I believe the VAWT was trickle charging a separate 12 Volt system.

"I spent half my money on women and booze...the other half I wasted" -W.C. Fields

[feral air]

That seems like it would be the easiest way to go if you're gonna do it. If your tower is strong enough you could even retrofit a vawt (in theory, anyway) for a little something extra.

[Woofer]

How would the Genny turn into the wind if it was half way up a tower ?

[Devo]

I would do mine just as the one on the top but the sleeve would be down the tower farther on a stop , it would just swivel around like the top one but this would wear the tower at a mid point with out a changeable bushing.

The lower mill would have to be small enough to go between the guys & the tower would have to be strong enough to take the extra strain

Devo

[zeusmorg]

The ideal design of a tower is to place your wind generator at the optimum height for airflow. Placing a second at a lower altitude would just limit the amount of useable windpower to that unit, so you would be better off having a second tower for two reasons, optimum airflow and structural strain. The only addition i could see would maybe be a low power savonus VAWT mounted lower.