Sunny Boy upgrade question [RE-wrenches]

[Allan Sindelar]

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Is your computer freezing up or slowing down?
Repair corrupt files and harmful errors - protect your PC
Take a 2-minute PC health check-up at no charge!
http://click.topica.com/caadOuabz8Qcsbz9JC9a/PC PowerScan
-------------------------------------------------------------------

Esteemed Wrenches,
How would you solve this? Two years ago we installed a batteryless system
with a Sunny Boy 1800 and seven BP SX140s, with racks in place for a second
7-module array in the future, when the client could afford it. (This is the
client that was featured in the RE Financing article in HP103:97, who
financed his system through the Permaculture Credit Union.)

He's ready to add the second row of seven modules now, and SX140s are no
longer available. We can get 160s and 170s, I think. I would expect that as
long as the MPP voltage is closely aligned (it's close but not perfect, 34V
vs. 35 at mpp), and the cell type is similar (it is, polycrystalline), it
should be OK to mix outputs, as the two strings are in parallel and combine
prior to the inverter.

Any thoughts on this are welcome.

Allan at Positive Energy

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Is your computer freezing up or slowing down?
Repair corrupt files and harmful errors - protect your PC
Take a 2-minute PC health check-up at no charge!
http://click.topica.com/caadUl2bz8Qcsbz9JC9f/PC PowerScan
-------------------------------------------------------------------

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