[RE-wrenches] FW: Enphase performance

[Peter Parrish]

All meters are analog at the point of measurement, because the signals that
are being measured are analog. What makes a meter "digital" is the
conversion of the original analog data to digital format and downstream data
manipulation. Therefore I doubt digital meters are fundamentally more or
less accurate than analog.
 
There is one point I would like to make: we have not used the GE I70S, the
electromechanical (100% analog) meter with pointers, for several years now.
We were told by a Southern California Edison engineer that they were not
reliable (i.e. stopped working) and they were less accurate than +/-5%. Sure
enough within a month the meter in question stopped worked and required a
"rap" on the bezel to start working again, only to freeze up again in a few
days. I remember two others that stopped working (one perhaps never worked).
We got these puppies from Austin International in SC. We use the Itron
Centron C1S and have been happy ever since.
 
- Peter
Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com  
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885

 
  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Keith Cronin
Sent: Friday, May 07, 2010 12:28 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] FW: Enphase performance
 
Makes you wonder what is officially calibrated to what....is digital more
accurate or analog utility meters...??
 
  _____  

From: Marco Mangelsdorf <marco at pvthawaii.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Cc: Douglas Bath <Douglas at pvthawaii.com>
Sent: Thu, May 6, 2010 8:11:16 PM
Subject: [RE-wrenches] FW: Enphase performance

Marco,
 
I have a revenue grade kWh meter on my 3 Enphase 175 system that is owned by
the utility (production based incentive in WA state) and the Enphase
monitoring reads about 6% over the revenue meter. This has been over a one
year period. I've been very pleased with the performance using either
measurement.

Brad
AEE Solar
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20100507/8785b08a/attachment-0003.html>