AIR X 400w wind generator- any good??

[Norman Webb]

I am looking at getting one of these to compliment my 200W 220AH solar
setup.

Has anyone had experience with the AIR x models?
regards

Norm

 

[wmbjk]

I am looking at getting one of these to compliment my 200W 220AH solar
setup.

Has anyone had experience with the AIR x models?
regards

Norm

I've had an Air 303 (factory converted to an almost-403) for about 11
years. It quit again a while back, so I'll be probably be scrapping it
next time I lower the tower
http://www.citlink.net/~wmbjk/11wind_power.htm.
The AirX should be better in many ways, but make sure you know what
you're buying http://www.wind-works.org/articles/sm_AirXtest.html.
They may have improved it by now, and depending on your wind speeds
and application, any premature regulation may not be an issue anyway.

Wayne

 

[Derek Broughton]

I am looking at getting one of these to compliment my 200W 220AH solar
setup.

Has anyone had experience with the AIR x models?

I have one. In hindsight, I don't think it's been worthwhile. It produces
very little power - whenever the wind gets high (which it does here often),
it shuts itself down to protect itself. The window of opportunity to
produce that nominal 400W is pretty small.

 

[[email protected]]

I have one. In hindsight, I don't think it's been worthwhile. It produces
very little power - whenever the wind gets high (which it does here often),
it shuts itself down to protect itself...

Why not keep producing 400 watts? Lower the load impedance
until it begins to stall, with a constant 400 watt output...

Nick

 

[wmbjk]

Why not keep producing 400 watts? Lower the load impedance
until it begins to stall, with a constant 400 watt output...

Nick

The Air 403 could make 400W at high revs, but overspeed control was
via noisy blade-flex stalling. The AirX did away with the blade flex
thing, and instead added circuitry to brake the turbine once wind
speed gets to about 24mph. Which made for a quieter machine but hurt
performance http://www.wind-works.org/articles/sm_AirXtest.html. Even
if the circuitry could be modified to eliminate the braking, that
would likely kill the overspeed protection. If there were a way to get
400W out of that thing without noise, you can bet that SWWP would have
done it.

Wayne

 

[[email protected]]

The Air 403 could make 400W at high revs, but overspeed control was
via noisy blade-flex stalling. The AirX did away with the blade flex
thing, and instead added circuitry to brake the turbine once wind
speed gets to about 24mph. Which made for a quieter machine but hurt
performance
Odd.

http://www.wind-works.org/articles/sm_AirXtest.html.

Even if the circuitry could be modified to eliminate the braking, that
would likely kill the overspeed protection. If there were a way to get
400W out of that thing without noise, you can bet that SWWP would have
done it.

I wouldn't take that as a given. Seems to me one could brake the turbine
electrically and make rigid blades partially stall without lots of noise.
Can you stop an AirX by shorting the output wires together?

Nick

 

[Norman Webb]

I got an offer I couldn't refuse so I bought one.
Since I divide specs by 2 at least, if I get 200w I will be happy. When I
get it setup I'll keep you posted.


Norman Webb wrote in message

 

[wmbjk]

Can you stop an AirX by shorting the output wires together?

Yes, see page 12 http://tinyurl.com/ycryjk. Changing the existing
circuitry might be tough if it's sealed as it was on the 303.

Wayne

 

[George Ghio]

I got an offer I couldn't refuse so I bought one.
Since I divide specs by 2 at least, if I get 200w I will be happy. When I
get it setup I'll keep you posted.


Norman Webb wrote in message

What the waynekers won't tell you about wind power;

<http://s78.photobucket.com/albums/j103/GGhio/>

 

[sylvan butler]

I wouldn't take that as a given. Seems to me one could brake the turbine
electrically and make rigid blades partially stall without lots of noise.

Partial stall may not be sufficient. With blades stopped, there is
essentially zero current. Trying to draw sufficient current to keep the
blade speed slow enough may require drawing too much current for the
generator to safely handle and overheating could result. In this
situation, full stall (blades stopped) might be the only solution.

sdb

 

[[email protected]]

[email protected] wrote:

Partial stall may not be sufficient. With blades stopped, there is
essentially zero current. Trying to draw sufficient current to keep the
blade speed slow enough may require drawing too much current for the
generator to safely handle and overheating could result. In this
situation, full stall (blades stopped) might be the only solution.

It seems to me there must be a situation inbetween, with an output around
400 watts that does not increase with windspeed.

Nick

 

[sylvan butler]

It seems to me there must be a situation inbetween, with an output around
400 watts that does not increase with windspeed.

How could that be?

A given swept area and a given power output means a certain wind speed.
If the windspeed increases, the power output must increase or the swept
area must decrease.

sdb

 

[[email protected]]

How could that be?

A given swept area and a given power output means a certain wind speed.
If the windspeed increases, the power output must increase or the swept
area must decrease.

According to Wayne(?), if we short the output, the blades stop and the
windmill produces no power. Where does the windpower go? I suggested
"partially shorting the output" with a clever controller to limit
the output to about 400 watts as the windspeed increases.

Nick

 

[AJH]

You are assuming that the efficiency remains constant. Suppose you have
a wind turbine controller that can reduce the efficiency of the turbine,
say by adding more electrical load. This controller could then be set
to let the wind turbine run 'wild' up to a certain output, say 400W.
Above that it could make the turbine less efficient so that it continues
to produce about 400W even at much higher wind speeds.

The corollary of that is that an intelligent controller would sense
the wind speed and load the turbine to maximise its output, whilst
protecting it from over speed. In practice is this how controllers
work?

AJH

 

[sylvan butler]

You are assuming that the efficiency remains constant. Suppose you have
a wind turbine controller that can reduce the efficiency of the turbine,
say by adding more electrical load.

That increases the power output of the generator. Not necessarily the
system, but the current flow in the generator will increase. At some
point this increased current flow will be too much and without some
other mechanism, the generator will be damaged.

The other way to decrease efficiency is to turn out of the wind, or furl
the blades a bit, both of which effectively reduce the swept area.

Don't forget we were talking about the AirX.

sdb

 

[sylvan butler]

According to Wayne(?), if we short the output, the blades stop and the
windmill produces no power.

That is correct.

Where does the windpower go?

It blows on past, i.e. it is not harvested because the blades are not
turning. The reason the blades do not turn, is the short hugely
increases the starting torque required.

I suggested
"partially shorting the output" with a clever controller to limit
the output to about 400 watts as the windspeed increases.

"partially shorting" is just a heavier load. A heavier load increases
current flow in the generator. Most are not designed to handle that,
thus the power output limitations and risk of overheating.

Perhaps you meant "periodically shorting". This will likely not
succeed, as the start/stop (or even heavy pulsing) of the blades can be
mechanically stressful. Also, if the blades are turning too fast, the
shorted windings may not be sufficient to stop that much torque. It is
much safer to stop the blades (by shorting the generator) near the power
threshold rather than far in excess of the power threshold, then keep
them stopped rather than try and stop an overspeed condition.

sdb

 

[[email protected]]

"partially shorting" is just a heavier load. A heavier load increases
current flow in the generator. Most are not designed to handle that,
thus the power output limitations and risk of overheating.

Then again, we have more wind to keep it cooler.

Nick

 

[Harbin Osteen]

A governor to change the pitch of the blades would be idle.
It would have good starting torque, and a coarser pitch for
high wind conditions. Don't know if this was mentioned in
another post.

--

SeeYaa Harbin Osteen KG6URO

When American Citizens with dual citizenship pledges allegiance
to the flag, to which flag do they pledge allegiance too?

-

 

[sylvan butler]

A governor to change the pitch of the blades would be idle.
It would have good starting torque, and a coarser pitch for
high wind conditions. Don't know if this was mentioned in
another post.

That's sort of the same concept as the original AIR. It used
intentional blade flex to change the pitch of the blades in higher wind.
People complained about the noise, but it was a clever design, IMHO.

sdb