Inverter Shoot-Out continues [RE-wrenches]

Mon Mar 29 07:54:09 PST 2004

===========================================================
Are you looking for savings on products you use everyday? 
Visit Quality Health today and see the coupons, free 
samples and special offers our members enjoy each and 
everyday.
http://click.topica.com/caab5n1bz8Qcsbz9JC9a/ Ivo Interactive
===========================================================

I guess I'll chime in.  In my view the issue is overall system
performance, and being able to certify systems which are reasonably
likely to produce the estimated amount of energy.  To me this means more
than a few real-world test labs given the climatic differences of North
America.  Of course the final arbiter of what a system does is energy
produced, yes I did say it.  I also agree that +/- 10% is way too loose
for PV manufacturers to rate at. 

Already a trend is beginning for funding agencies to require accurate
production information (CEC accepted meters built into inverters are now
a 'feature' on some).  It is time for module manufacturers to tighten
their scales.

Regards,

Ezra 

DragonSun Consulting
Morewater Road
Lasqueti Island, B.C. V0R 2J0

ezra at lasqueti.net
250 333 8650 voice

-----Original Message-----
From: Michael Welch [mailto:michael.welch at homepower.com] 
Sent: Sunday, March 28, 2004 5:12 PM
To: RE-wrenches at topica.com
Subject: Re: Inverter Shoot-Out continues [RE-wrenches]

===========================================================
Are you looking for savings on products you use everyday? 
Visit Quality Health today and see the coupons, free 
samples and special offers our members enjoy each and 
everyday.
http://click.topica.com/caab3ozbz8QcsbAlphCa/ Ivo Interactive
===========================================================

Hi gang. More from Henry for Matt & Marco.

"Marco Mangelsdorf wrote ...
Come on now...what else exactly are good, safe, UL-listed inverters
supposed to do but maximize their AC output from any given PV array"

Hi Marco,

I am NOT saying inverters shouldn't maximize the available solar panel
power into grid power. I AM saying that to verify the Inverter
software/hardware works , you would put it through a know set of IV
input and verify its output. The Test can be derived  from the sampling
of as many "real world" array's as one wishes ... it is just translated
into a programmable DC supply as the input , voltage and current , vs.
solar panels voltage and current.

IMHO trying to use data from real live arrays and being able to
partition what components are the causes is next to impossible and
equipment/time consuming if you DO try to do it. You have inverters ,
wires , connectors , mounting systems , solar panels , weather , both in
temperature/wind/clouds ect. I've done my share of side-by-side testing
, both in my system and beta tester for the -UPG. Real systems ARE good
for making sure there aren't any gross error's , but no two arrays are
identical ... my HP91 was to show there was a 20%+ issues , OK for
arrays , I'm talking about how inverters react to variable conditions ,
impossible to do on a real array an validate beyond gross failures and
comparing 2% rated differences on the 10 inverters out there now.

I have seen first hand what is used from the engineering side , there is
no standard , a company might have a local array or two but a bulk of
the testing is done at places like Sandia or Customer Beta Sites or even
production customer sites. Not exactly a controlled study group to
verify the product will work in the extremes weather (isonalation)
variation can throw at the inverters .. So in Summary , this is why I
say YES to a programmable power supply with a standard isonalation
pattern that ALL inverters , on the bench , can be verified too. If this
was done before units are shipped , there wouldn't be field issues ,
because it was proven to work !

"Matt Tritt wrote ... From the contact I have had with the new (and the
old) models, they just plain make too much audible noise.

Hi Matt,

I would respectfully challenge  that a Suntie -UPG is a noise problem
... are you certain that it was a UPG ?. the ST and XR Sunties , the fan
Will come on at 100 watts and go  full blast ... the UPG , the fan has
13 speeds , all controlled by the processor and is temperature driven. I
have a pair of Sunties mounted on my outside Garage wall at my home and
from the inside of this wall you can barely hear them working , in 90
degree weather putting out 2K plus watts to the grid. It has to be
REALLY hot to get the fan to full.  I wouldn't put the inverter in my
living room and to a degree this is the price one pays for an inverter
that puts out 2500 watts at 45C ambient .. No BS on the specifications ,
BTW , ever hear a Sunnyboy late in the afternoon when the transformer
has been baking , the 60 Hz buzz isn't exactly like a trickling brook :)

Henry Cutler

Michael Welch

------------------------
"When one tugs at a single thing in nature, he finds it attached to the
rest of the world."
                                -John Muir

Michael Welch, michael.welch at homepower.com
     Home Power magazine
     www.homepower.com
     To reach me: 707-822-7884
     To reach Home Power: 800-707-6585

===========================================================
Are you looking for savings on products you use everyday? 
Visit Quality Health today and see the coupons, free 
samples and special offers our members enjoy each and 
everyday.
http://click.topica.com/caab5n1bz8QcsbAlphCf/ Ivo Interactive
===========================================================

- - - -
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/etiquete.htm

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

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

===========================================================
**** Bounces like rubber! Shatters like ceramic! ****
Discover Crazy Aaron's Thinking Putty in grown up 
handfuls. It's the creativity unleashing, mood enhancing 
desk toy!
http://click.topica.com/caab4CEbz8Qcsbz9JC9f/ Crazy Aaron Enterprises
===========================================================

- - - -
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/etiquete.htm

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