[RE-wrenches] Tilt biased....
holtek at sbcglobal.net
holtek at sbcglobal.net
Sun Apr 18 08:55:02 PDT 2010
Allan,
According to Unirac tech, the code manual only addresses solid wall structures. He was also the one who told me about the greater windloads on open structures. His suggestion was to get an engineer involved, but on a system this size I am hoping to avoid that additional cost. I did fill out their online design parameter form, so I'm hoping to get enough feedback from that to come up with an over-engineered way to anchor the array to the frame structure of the carport..........
Holt E. Kelly
Holtek Fireplace & Solar Products
500 Jewell Dr.
Waco TX. 76712
254-751-9111
www.holteksolar.com
----- Original Message -----
From: Allan Sindelar
To: RE-wrenches
Sent: Sunday, April 18, 2010 2:17 AM
Subject: Re: [RE-wrenches] Tilt biased....
Holt,
Feedback re the low tilt angle: Go for it, you're good.
Re wind loading: check out UniRac's Code Compliant Installation Manual, http://www.unirac.com/pdf/ii227.pdf, especially pages 3-9.
Less wind loading is one of the main reasons for going with a lower tilt angle. Another is closer module row spacing (at 3X height RoT) without inter-row shading.
No experience with Enphase.
Allan
<![endif]-->
Allan Sindelar
Allan at positiveenergysolar.com
NABCEP Certified Photovoltaic Installer
EE98J Journeyman Electrician
Positive Energy, Inc.
3201 Calle Marie
Santa Fe, New Mexico 87507
505 424-1112
www.positiveenergysolar.com
holtek at sbcglobal.net wrote:
Searching for opinions.....is this "over design"?
Designing small system (2.35kW). Customer uses gas for heating. Typical A/C unit. I was thinking of biasing the tilt to summer production for greater offset of summer demand (lat 31.6, proposing 18). No net metering in this part of the world. PVwatts shows a drop of 2% /yr. in production , 5% higher production for A/C months. Feedback?
Also, this array will go on a carport. I understand that windloading is actually greater for an open structure than one with walls (another reason for lower tilt) - is there any one that can direct me to data on finding out how much more?
Lastly, what is a good avg. target derate factor for Enphase inverters (real world)?
Holt E. Kelly
Holtek Fireplace & Solar Products
500 Jewell Dr.
Waco TX. 76712
254-751-9111
www.holteksolar.com
----------------------------------------------------------------------------
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches at lists.re-wrenches.org
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
------------------------------------------------------------------------------
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches at lists.re-wrenches.org
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100418/126cc694/attachment-0004.html>
More information about the RE-wrenches
mailing list