PV Inverters module strings [RE-wrenches]

Bill Brooks billbrooks7 at earthlink.net
Thu Mar 29 23:51:14 PST 2001 

Joel,

It's a temperature issue so you cannot make a blanket statement for all
locations. You can say for all of California, except the Sierra's, 24
crystalline modules in series will generally work. If the open circuit
voltage of a crystalline module is low enough, we may be able to go to
25-modules in series right along the coast of California, or any where it
never goes below freezing. Solarex MST-43, UniSolar-all products, and any
other low fill-factor module (CdTe) will likely not work with this inverter
because the difference between the Voc and Vmp is too great.

The temperature correction factors come from Table 690-7 in the NEC. This
correction factor table only applies to crystalline modules, but we can rule
out thin films for the time being because even though their correction
factors are less--even with no correction factors they will not work.

Bill.


-----Original Message-----
From: Joel Davidson [mailto:joeldavidson at earthlink.net]
Sent: Thursday, March 29, 2001 6:36 PM
To: RE-wrenches at topica.com
Subject: Re: PV Inverters module strings [RE-wrenches]


Kent - We understand that you can not endorse specific solar modules, but
(like
mount manufacturers) you can make a list of modules that work with your
inverters and the number of modules in series. You can caveat the list
however
you feel necessary. Here's a start with the first 2 modules from this
on-going
discussion.
Siemens SR100 - 24 modules
BP Solar BP2150 - 12 modules
Siemens SP75 - ? modules
BP Solar BP-585UL - ? modules
ASE Americas ASE-300 - ? modules
Astropower AP-120 - ? modules
Astropower APX-75 - ? modules
Kyocera KC120-1 - ? modules
Photowatt PW1000-95 - ? modules
Energy Photovoltaics EPV-40 - ? modules
Solarex MST-43 - ? modules
Solarex MSX-120 - ? modules
United Solar SSR-128 - ? modules
United Solar US-64 - ? modules
Other modules ?



Kent Sheldon wrote:

> William, yes I work for the former Trace Technologies, now called Xantrex
> Distributed Industrial and Utility Markets Business Unit. I am the POC for
> applications questions on the PV series inverter line. Unfortunately,
being
> that we manufacture inverters, we do not specify specific PV panels, or
> arrangements to use with our inverters. This is the job of the system
> integrator. What we have done is to specify an allowable voltage operating
> window for the inverter. The type or design of the PV module is not
> important, as long as the input voltage constraints are met. You must
decide
> what configuration of PV works best for your application, orientation,
> regional location, code requirements, etc. The calculations are rather
> straightforward, but require much information specific to the site
> installation. I believe Bill Brooks walked you through a possible
solution,
> which may or may not be adequate for your application.
>
> Regards,
>
> Kent Sheldon
> Product Manager - Photovoltaic Engineering Group
> Xantrex/Trace Technologies Inc.
> 925 245 5463/925 245 1022 Fax
> kentsheldon at tracetec.com  www.xantrex.com
>
> -----Original Message-----
> From: William Miller [mailto:wrmiller at slonet.org]
> Sent: Thursday, March 29, 2001 12:28 PM
> To: kentsheldon at tracetec.com
> Cc: RE-wrenches at topica.com
> Subject: RE: PV Inverters module strings [RE-wrenches]
>
> Kent:
>
> Thanks for your reply.  I understand you work for Trace Technologies, the
> designer and builder of the PV series inverters.  If you don't have
> specific application knowledge, is there someone in your company who does?
>
> I need to know how many SR100 panels to use with a PV5 and a PV10 for a
> given climate.  Please correct me if this is not an appropriate question
to
> ask of a manufacturer.
>
> I would assume this type of question is fundamental to the support of a
> product you manufacture and I would be disappointed if Trace Technology
> could not give me very precise data to allow me to purchase and use a
> product in their line.
>
> Thanks,
>
> William Miller
>
> At 11:57 AM 3/28/01 -0800, you wrote:
> >William, sorry to take so long to get back to you. I am inundated right
> now.
> >Unfortunately, I rarely get involved in the PV array sizing calculations.
> >The only advice I can give you is to make sure the peak power voltage
stays
> >between 330 to 600. NEC drives most of the voltage window constraints,
> >however the manufacturer temperature deratings for the specific PV model
> >will also impact the calculations. A side note, the inverter will not
power
> >track below the minimum allowable DC level. So if your PPTV is lower than
> >minimum, the power tracker will back off and continue power production at
a
> >less efficient point on your array curve. Right now the minimum DC
> operating
> >voltage is around 328. We are putting some new software through UL which
> >will allow the minimum bus voltage to be a function of the AC line
voltage,
> >allowing for operation below 300Vdc. It will be a few months before this
is
> >available.
> >
> >Please contact me if you have any further questions.
> >
> >Kent Sheldon
> >Product Manager - Photovoltaic Engineering Group
> >Xantrex/Trace Technologies Inc.
> >925 245 5463/925 245 1022 Fax
> >kentsheldon at tracetec.com  www.xantrex.com
> >
>
> __________________________________________________________________
> William Miller
> SLO Communications: Communications and Power Systems Consulting
> PO Box 50, Santa Margarita, CA 93453
> Voice :805-438-5600             Fax: 805-438-4607       VMail:
805-546-4875
> email: wrmiller at slonet.org
> License No. C-10-773985
> _____________________________________________________________
> Compatibility:
> Word processor: WP7
> Spreadsheet: Quatro Pro 7
> CAD: Microstation 95, DXF, Visio 4.1T
> _____________________________________________________________
> "I stand by all the misstatements that I've made." Dan Quayle
> __________________________________________________________________
>
> - - - - - - -
> To send a message:
>  RE-wrenches at topica.com
>
> The archive of previous messages:
>  http://www.topica.com/lists/RE-wrenches/
>
> List rules & etiquette:
>  http://www.mrsharkey.com/wrenches/etiquete.htm
>
> To unsubscribe send a message to:
>  RE-wrenches-unsubscribe at topica.com
>
> To check out the other RE-Wrench participants:
>  www.mrsharkey.com/wrenches/index.html
>
> Hosted by Home Power magazine:
>  www.homepower.com
>
> For info contact list moderator by email:
>  michael.welch at homepower.com
>
> - - - - - - -
> To send a message:
>  RE-wrenches at topica.com
>
> The archive of previous messages:
>  http://www.topica.com/lists/RE-wrenches/
>
> List rules & etiquette:
>  http://www.mrsharkey.com/wrenches/etiquete.htm
>
> To unsubscribe send a message to:
>  RE-wrenches-unsubscribe at topica.com
>
> To check out the other RE-Wrench participants:
>  www.mrsharkey.com/wrenches/index.html
>
> Hosted by Home Power magazine:
>  www.homepower.com
>
> For info contact list moderator by email:
>  michael.welch at homepower.com
>

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

The archive of previous messages:
 http://www.topica.com/lists/RE-wrenches/

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

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

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine:
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com


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

The archive of previous messages: 
 http://www.topica.com/lists/RE-wrenches/

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

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

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine: 
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

==^================================================================
EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9
Or send an email To: RE-wrenches-unsubscribe at topica.com
This email was sent to: michael.welch at homepower.com

T O P I C A  -- Learn More. Surf Less.
Newsletters, Tips and Discussions on Topics You Choose.
http://www.topica.com/partner/tag01
==^================================================================

More information about the RE-wrenches mailing list