Fixed vs. Tracking for Pumping (was:PV Trackers) [RE-wrenches]

Thu Sep 16 16:37:29 PDT 2004

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Are Americans getting fat? Give us your opinion and win.
http://click.topica.com/caacDvYbz8Qcsbz9JC9a/PermissionData
-------------------------------------------------------------------

  Windy,

  Of course you're right about the extra Watts with most solar pumps, but
this sure wasn't the case with the Solastar. They had a maximum Wattage and
a minimum Wattage allowed, saying that exceding the "allowable" module power
automatically voided the controller warranty. Maybe this was BS but they
made it quite clear.

  Our Monoflo submersibles have three motor and controller versions; the 300
SMC that allows a maximum of 4 X 75 W modules of 30 to 100 VDC to 5 amps
maximum;

  the 600W SMC maximum of 8 X 75 Watt modules, 30 to 160 VDC and 5 amps max

  The 1200W SMC with a max of 16 X 75 W mod's, 30 to 160 VDC and 10 amps
max. All these controllers convert to 3 phase switched DC of 0 to 100 Hz
motor output.

  These values are not to be exceded. So say's the factory, and I believe
them.

  I completely agree with your take on to track or not to track. All my
customers (ranchers mostly) would agree as well I'm sure. Plus, there's the
extra size and windage of a bigger fixed array versus a smaller tracked
array; bigger pole and deeper hole. Hey, I like that.

  Matt T

  ----- Original Message ----- 
  From: "Windy Dankoff, Dankoff Solar" <windy at dankoffsolar.com>
  To: <RE-wrenches at topica.com>
  Sent: Thursday, September 16, 2004 3:33 PM
  Subject: Re: Fixed vs. Tracking for Pumping (was:PV Trackers)
[RE-wrenches]

  Your free subscription is supported by today's sponsor:
  -------------------------------------------------------------------
  Do you love your country? Get a Free USA T SHIRT click here to
  receive your gift.
  http://click.topica.com/caacDvPbz8QcsbadqCja/PermissionData
  -------------------------------------------------------------------

  Matt,

  With almost any solar pump system, you can go to 2X the required PV
  watts, or more, without problem. The pump system draws according to the
  load, and has overcurrent protection in case of overload.  What blows
  the controller is more likely to be excessive Voc, and that's not an
  issue if the array is wired for the right voltage.

  Is array oversize an economical approach?
       In a cloudy climate for domestic water (needed every day) -- yes,
  potentially. Tracking won't help so much.
       In a dry sunny climate for agriculture (not needed much in cloudy
  weather) -- no. Tracker is more economical.
       With a very small PV array -- yes. Extra watts may cost less than a
  tracker
       Larger array -- no. Tracking is much cheaper than PV watts.

  This is a theoretical discussion of course, not considering potential
  problems and preferences around the matter of trackers in the real
  world. I CAN say that there are lots of ranchers who use passive
  trackers with enthusiasm -- most often, the small and medium sizes.

  Windy

  On Sep 16, 2004, at 3:45 PM, Matt Tritt wrote:

  >
  >
  > Your free subscription is supported by today's sponsor:
  > -------------------------------------------------------------------
  > Sponsor a child today through Children International.
  > Give a desperately poor child hope for a brighter future.
  > For only $18 a month you can make a difference!
  > http://click.topica.com/caacBBFbz8QcsbAj7kya/ChildrenInternational
  > -------------------------------------------------------------------
  >
  >   Well, I bet the problem I'm having convincing you how I'm right (LOL)
  > about this is the kind of pumps you're working with. Or maybe not!
  >
  >   Here's the way I see it: A particular pump is designed to operate
  > withiin
  > a particular, narrow window of efficiency to deliver a maximum
  > head/flow
  > ratio. If this pump has a 1200 Watt motor let's say, you aren't going
  > to be
  > able to give it MORE than it is capable of using without damaging the
  > pump,
  > damaging the controller, voiding the warranty or blowing off the extra
  > Watts
  > as waste heat, even though a certain amount of extra run time can be
  > achieved. Maybe.
  >
  >   If you use a tracker you can fit the array output to the pump motor
  > exactly AND have maximum output during the entire day - month - year;
  > plus
  > you keep the warranty and the machinery in tact. Using a good tracker
  > (and
  > why shouldn't one last 30 years?) shouldn't worry you at all; yes
  > there may
  > be moving parts to watch, but so what?
  >
  >   I think that it's perfectly logical and acceptable to charge for
  > repairs
  > and maintenance of any machinery/equipment after the warranty is over.
  > All
  > equipment made is subject to wear and tear and maintenance, right? So
  > why
  > should a tracker be any different? O.K. the older Wattsuns can run you
  > ragged chaning motors, photo eyes and controllers. True, true, true.
  > And
  > yes, they all began failing within an unacceptably short period of
  > time.........That's why it's so terribly important to periodically
  > purge
  > your memory cells and start over!
  >
  >   Matt T
  >
  >
  >   ----- Original Message -----
  >   From: "Travis Creswell, Ozark Solar" <ozsolar at ipa.net>
  >   To: <RE-wrenches at topica.com>missionData
  >   -------------------------------------------------------------------
  >
  >   Hi Matt,
  >
  >
  >
  >   Moderator: michael.welch at homepower.com
  >
  > Your free subscription is supported by today's sponsor:
  > -------------------------------------------------------------------
  > Click here and walk away with your free Chevy collectible.
  > http://click.topica.com/caacDvMbz8QcsbAj7kyf/PermissionData
  > -------------------------------------------------------------------
  >
  > - - - -
  > To send a message: RE-wrenches at topica.com
  >
  > Archive of previous messages:
  > http://lists.topica.com/lists/RE-wrenches/read
  >
  > List rules & etiquette: www.mrsharkey.com/wrenches/etiquete.htm
  >
  > Check out participant bios: www.mrsharkey.com/wrenches/
  >
  > Hosted by Home Power magazine
  >
  > Moderator: michael.welch at homepower.com
  >
  >
  >
  >
  >
  >
  >
  >

  Your free subscription is supported by today's sponsor:
  -------------------------------------------------------------------
  Is Gay Marriage a Civil Rights Issue? Click here and win.
  http://click.topica.com/caacDvRbz8QcsbadqCjf/PermissionData
  -------------------------------------------------------------------

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

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

  List rules & etiquette: www.mrsharkey.com/wrenches/etiquete.htm

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

  Hosted by Home Power magazine

  Moderator: michael.welch at homepower.com

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Do you live vicariously through Reality TV? Let us know and win!
http://click.topica.com/caacDv1bz8Qcsbz9JC9f/PermissionData
-------------------------------------------------------------------

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

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

List rules & etiquette: www.mrsharkey.com/wrenches/etiquete.htm

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
--^----------------------------------------------------------------