cost per kWh [RE-wrenches]

[Eric Smiley]

I think it makes more sense on a battery based system without MPPT to
use peak sun hours and array mpp amps (Imp). Amps are pretty much
proportional to sun light intensity and the modules are going to produce
Imp or greater at battery charging voltage and elevated temperatures.
For simplicity, I keep all my calculations on battery based systems in
terms of amps and amp hours. Working in watts means using two different
"typical" battery voltages -- one for charging and one for discharging
-- which is necessarily vague.

If you have the time, you can copy and paste hidden cells in RetScreen
onto a blank worksheet and decipher what is going on in the background.
Another engineer told me about this and discovered that RetScreen
actually calculates monthly energy values but keeps them hidden and only
displays a yearly summary.

Eric Smiley
Project Leader
Photovoltaic Energy Applied Research, Technology Centre
British Columbia Institute of Technology
Burnaby Campus

NE25 - 3700 Willingdon Avenue
Burnaby, British Columbia
Canada V5G 3H2

phone: 604.432.8657    fax: 604.436.0286
esmiley at bcit.ca             www.tc.bcit.ca

The information contained in this E-mail is intended for the addressee
only.  If you have received this in error please delete it.

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

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

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

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

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
==^================================================================
This email was sent to: michael_welch at sbcglobal.net

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

TOPICA - Start your own email discussion group. FREE!
http://www.topica.com/partner/tag02/create/index2.html
==^================================================================