Trace efficiency [RE-wrenches]

[Jason Fisher, Aurora Energy]

Sparky and all,

Here are some numbers from an acquaintance in New England whom metered his
system last year:

>I now have 6 months data on my utility-intertied system (1060 Wp BP Solar
panels, Trace 4024SW, eight L-16 batteries).
>in these 6 months (July-Dec 99).  The system had a DC output of 469 kWh.
Net AC output was 280 kWh, for an effective inverter efficiency of 60%.
Yuck!

I installed an SW/ battery backup system down here in Maryland which the
owner had me set up a metering package including an Omnimeter and dual AC
kWh meters (AC input and output) which he used to calculate a similar DC to
AC efficiency of the SW of about 70%.  That is actual DC in from panels, not
rated DC output.  These systems, being "sell" systems, suffer from being on
and trickle charging at night.  Anyone else have numbers to compare?

----

Jason Fisher
Aurora Energy
86 Conduit St.
Annapolis, MD 21401
USA

Voice/ Fax: 410-268-3088
email: aurora at toad.net



> -----Original Message-----
> From: R. Sparks Scott [mailto:sharkey at mrsharkey.com]
> Sent: Sunday, July 09, 2000 10:39 PM
> To: RE-wrenches at topica.com
> Subject: Trace efficiency [RE-wrenches]
>
>
>
> 	Todd and Jason;
>
> 	I'm assuming that you are using the menu item 4-Meters to
> calculate your
> SW's output power. I have found that these readings are next to
> useless for
> anything that requires accuracy. If you're not pushing too many amps back
> into the grid, put your digital mulitmeter in series with the AC line and
> get the truth. An amp clamp can be used for higher current
> installations. I
> put a permanent AC current transformer in my AC feed and connected it's
> calibrated DC output to an analog meter, 0-10 amps scale. Now I can
> calculate output using current to the nearest tenth of an amp.
>
> 	-S
>
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To unsubscribe send an email message to: <RE-wrenches-unsubscribe at topica.com>

To check out who the other RE-Wrench participants are, go to <http://www.mrsharkey.com/wrenches/>

Hosted by Home Power magazine: <http://www.homepower.com>

for info contact: <michael.welch at homepower.com>
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Newsletters, Tips and Discussions on Your Favorite Topics