|
|
|
|
|||||
|
||||||
From: Ken James (no email)
Date: Wed Jul 20 2005 - 06:08:49 EDT
> The Ferris Windpower 200 advertises 15 Amp output in about 18 kts.
> of wind. I sure hope it doesn't take that much wind to get your
> boat up to 5 kts.? I assume that your wind generator does a lot
> better than that?
No, my boat is an S&S design, pretty fast for her length, but my Air Marine
in 15 kts true wind (with the boat sailing 5 kts upwind) will make a couple
hundred watts, maybe more if the batterys are down.
The Ferris Windpower 200 advertises 15 Amp output in about 18 kts.
of wind. I sure hope it doesn't take that much wind to get your
boat up to 5 kts.? I assume that your wind generator does a lot
better than that?
Well, in retrospect I should not say my 11 lb genny with short blades does a
LOT better than that, (18 amps and I think I could get maybe 20-25) although
its curve for power available in the wind to power it actually extracts is
much better than a rewound car alternator. Its max output at 30 kts is
supposed to be well over 400 watts, maybe 450-500, but I do not have enough
battery capacity to verify that, as once it starts humming good my banks
fill up pretty fast and I never see that much current.
Remember that your wind gen is not inducing drag while it is
running.
Oh yes, it does. It knocks almost ten deg off how close to the wind I can
get sometimes, and takes 1/4 tp 1/2 kt in good wind.
While I have seen units advertising both low speed start-up and
great high speed output I have seen no independent test to verify
such.
I have seen plenty of test data, and they all show the problem as one that
is inherent in the car alternator design.
Essentialy, at slow speeds you can not induce enough of a field safely,
while at higher speeds you can, due to back emf effects.
With a perm mag design that is not a problem. Then brushless and switching
design further enhance efficiency.
Right now I have the blades off it for the hurricanes, debris cause broken
blades. -Ken
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/world-cruising/
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|