Wind gen tower spacing

[test lab guy]

I am doing some site planning for two shop built wind generators.  I am still piecing things together, just got the steel poles today.

The rotors will be on the order of 16 feet in diameter, pole height is approximately 56 feet.

The locations I have selected put the two about 50 feet apart.

Any comments or advice on the spacing??

Thanks,

TLG

[Chiron]

With the large wind turbines it's usualy 5 blade diameters or the total height of the tower and blades at thier highest plus 10% whichever is furthest.

Unless one generator is likely to be in the wind shadow of the other there probably isn't a problem with 50' spacing.

HTH

Chiron

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[test lab guy]

Chiron, thanks for the info.  I do need to find what the prevailing wind direction is and try not to put one in front of the other.

All of the big gens I have seen in fotos look like one can fall in any direction and not hit any of the other towers, which is what you mentioned.

A 56 foot pole spaced at 50 feet keeps things interesting, but I will look to see if I can get more spacing.

I am at the highest corner of the property which has those nasty overhead utility wires running down both edges.  I suppose if one of my gens falls I need to try to avoid hitting the wires  I am connected to coop power, and they don't like wind gens or solar, ie. no net metering.  Those stinkers!!

TLG

[test lab guy]

O.J. is that you??

[Ungrounded Lightning Rod]

All of the big gens I have seen in fotos look like one can fall in any direction and not hit any of the other towers, which is what you mentioned.

It can also throw a blade and have a low probability of the next one over.  (Imagine the domino effect if that one then throws ITS blades and gets the NEXT one, all down the line...)

For smaller mills thrown blades will have more reach as a percentage of size than with larger ones.  Speed is the same for a given TSR and thrown distance is mostly proportional to speed so it doesn't change a lot with the mill's scale.

In more detail:  The launch altitude DOES change, so a blade thrown downward at an angle will go farther for a high mill than a low one.  But if a blade is thrown upward at an angle its trajectory from launch to return to the mill's height will be the same regardless of mill size, i.e. it will NOT scale.  Only the part of the path down from there will give the higher mill more reach than the lower one.

(That's all neglecting differences in air friction and blade density, of course.)

I suppose if one of my gens falls I need to try to avoid hitting the wires

Throwing a blade or a detached tail into them would also get the power coop upset.  B-)

[Chiron]

I wouldn't be so sure about the big ones not tossoig blades as far as a small one.

The FPL site near Palm Spring, CA holds the unofficial "Lawn Dart Award" 70+ foot blade broke at the root, sailed past one tower and stuck into the lattice of the next tower. The blade stuck high enough that the blades on that turbine hit it, shattering all 3 of those blades and doing rather extensive damage to the tower itself.

I recall that those turbines were built before the "5 diameter" rule was used but the blade still traveled over 1000' before impaling itself at least 100' above ground.

This was not a proud moment for Vestas, I don't recall which of the V series was involved.

[test lab guy]

Chunking blades is not something I thought about (yet).  Hey, something to look foward to.  The dart board is quite large, fortunately more cows than people.

Thanks all for the help,

TLG