4 footer up on the silo

[Devo]

Here is a picture of the new 4 foot genny on the silo.Jerry a friend of mine put it up for me today (fear of heights).The wind was so slow that my 11 foot Dual rotor was spinning at about 60 to 100 rpm which produces no power , The 4 footer was up as high as 3.18 amps at 13 volts about 40 watts , I think I will get 100 watts easily!

I will post some output numbers later in the week if it gets windy & if I get my weather station up to measure the wind.

Devin

[Warrior]

Nice job, but something seems strange, the 4 footer was making 40 watts, but the 11 foot nothing? Should be the other way around right???

Warrior

[Nando]

Something is wrong, if 4 feet produces 40 watts, the 11 feet should produce to the square of the area ratios

11^2/4^2 = 121/16 = 7.5625 ; 7.5625 * 40 = 302 watts, what is going on ?.

Unless the 11 feet is in a wind shadowed area and the 4 feet in a clear area.

Or am I wrong ?>

Nando

[Flux]

This is most likely to be a difference in wind. The 4ft is high up on a silo, we have no idea what wind speed the other is seeing.

If they are at the same height and both in clean wind then the cut in of the big one may be way off.

Same problem with measuring power out of the 4ft, the anemometer needs to be at hub height and ideally about 8ft upwind to give decent results.

Flux

[Devo]

Yes The 4 footer is higher & probably catching higher wind , thanks for the tip on the wind gauge - I will try to get it 8 feet above.

Devin

[Nando]

Flux:

I wrote it in the sense to expect a response from the writer to see what is going on there and to visualize the whole setup.

Nando

[Devo]

They are calling for 30 kmh winds today up to 40 later on this evening. I have seen the new 4 footer hit 14.4 amps at 15.8 volts. I may have the tail to heavy , at 150 watts it is tracking about dead into the wind , just getting past the offset.I guess I'll see what she can handle if the wind picks up.

I am going to try to make a bracket to mount on top of the frame work that will go over the blades & place the anometer in front of the hub 8 feet upwind but this will take me some time & thinking...

What a great feeling I get when it's windy :-).This "Jerry Rigged" Alt seems to work quite well in the wind when a gust comes the meter moves....would # 17 wire take 10 amps up there? if so It should be able to take 30 with out stator trouble if the blades can push it there .

Devin