Inverter Load Analysis [RE-wrenches]

[Ray Walters]

<x-flowed>
Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Ben & Jerry’s® or Häagen-Dazs®?
Take our Nationwide Ice Cream Survey today! Receive a FREE* $100 
Restaurant Gift Card of your choice or $100 worth of Ben & 
Jerry’s® or Häagen-Dazs® ice cream for participating!
http://click.topica.com/caadKb7bz8Qcsbz9JC9a/Ice Cream Research Survey
-------------------------------------------------------------------

Hi All;

I have possibly a dumb question: I use a spreadsheet originally designed by 
Windy Dankoff, and it figures inverter average efficiency into the total 
energy calculation. I added a page that lists all the appliances and I list 
the inverter no load draw times the hours it will be on. Is this redundant?
I use a 92% efficiency number for the inverter overall, but should I raise 
this, since I'm adding in the inverter's no load draw in the other page?
For an average load of say 500 watts and a no load draw of 10 watts,  that 
is about 2% of the total inverter draw. I'm considering raising my inverter 
efficiency number by 2% to account for this.
Also, I was considering raising my battery efficiency number (currently I 
figure 88%) because many of the big loads (refrigeration, water pumping) 
occur more in the day, and so the battery isn't be cycled as much to power 
those loads. I was considering going up to 90 or92% for average battery 
energy efficiency on projects with larger daytime loads. (notice I said 
"energy efficiency" which is charging efficiency  x voltaic efficiency)
Off grid design seems to be much more difficult and time consuming than 
grid tie stuff. A lot more call backs too. I wonder if the days are 
numbered for us old fashioned off grid load analysis freaks. 10 times the 
trouble for half the pay will send even the best of us looking  for rebate 
programs.

Ray Walters
ray at solarray.com
President, SolarRay, Inc.
NABCEP Certified Solar PV Installer
BS Mechanical Engineering, UT Austin 88
Returned US Peace Corps Volunteer 

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Erase wrinkles without Botox! Nexiderm SP is clinically proven to 
reduce wrinkles by 68% Click here to get your 30-day free supply.
http://click.topica.com/caadHllbz8Qcsbz9JC9f/Nexiderm
-------------------------------------------------------------------

- - - -
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/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
--^----------------------------------------------------------------



</x-flowed>