Design guidance request [RE-wrenches]

Ray Walters walters at taosnet.com
Wed Jan 3 20:45:35 PST 2007


<x-flowed>

HI Allan;

We've got a Bergy XL.1 that we're running about 400 ft. Extra voltage 
drop isn't as big an issue with those. They all are 24 volt Dc at the 
batteries, but are a variable ac voltage from the wind turbine to the 
controller. At one time, I had a problem with actually making too much 
power from the windmill (over 1700 watts from 1000 watt rated unit) 
which was causing nuisance tripping of the 60 amp breaker. Bergey sent 
me a huge 1/2 ohm resistor (1000 watt rating) to install in line between 
the turbine and controller. Since then, I 've always undersized the 
cables a bit more to simulate the resistor. Since the turbine makes way 
over rated power, I've never had any complaints about line losses, and 
nuisance tripping is cured too. Also, Bergey has been really good to 
deal with.
I had another XL.1 last summer that actually took a direct lightning 
strike (burn marks on the cowling) and it just needed a new rectifier 
and main fuse.
When  doing the line loss calculations, I usually look at power at avg. 
speed (maybe 12 to 15 mph here) instead of getting worried about losses 
at full power. It seems the batteries top off fairly quickly in high 
winds, and then all that extra power becomes a liability in an off grid 
system.

Ray

 Allan Sindelar wrote:

>Wrenches,
>We do relatively little off-grid wind; mostly keeping a few of Windy's old
>Jake installations from the 80s spinning. Santa Fe County has a 35' height
>restriction and lots of sun, so we don't get too many wind installations.
>Today I got a lead call that I want to be prepared for (coming in on Friday)
>and I am requesting a little advice.
>
>The customer planned a ranch for grid extension, 1 3/4 miles at $48K and
>then couldn't get the easement. He thinks he needs about a 3kW array, but
>has also asked about wind. He has an existing water pumping windmill on a
>tower he says is at least 80'; so far so good. The water pumper served this
>ranch for years, but is disabled now, replaced by a 2HP submersible pump
>that runs off a welder/generator to fill a stock tank from time to time. The
>windmill tower is 300-350' from the house and the rest of the power system,
>and he asked if he could use it for a wind charger at that distance. I was
>generally encouraging, but need to be better prepared.
>
>>From this basic information, it sounds like a hybrid PV/wind would be a good
>bet. My first idea is a Windy Boy AC-coupled to a Sunny Island (or Outback),
>along with sufficient and redundant dump load to prevent overcharging and
>overspeeding. Is this a reasonable approach?
>
>But my main question is: what's a better way? Assuming we want to use the
>existing water pumper tower (and should we?), how should we set up for an
>assumed 400' run?
>
>Thanks in advance,
>Allan at Positive Energy
>
>
>
>  
>


- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------



</x-flowed>



More information about the RE-wrenches mailing list