Inverter meter reliability [RE-wrenches]

[Ian Woofenden, Home Power]

<x-flowed>


I'm surprised to see that a Sunny Boy 4000 that we installed this 
spring is tracking the utility's digital production meter very 
closely. Yesterday's cumulative reading was 629 on the utility meter 
(resolution is whole numbers) and 628.7 on the inverter.

Ian


>Peter.....Hello.....I used to work at Energy Outfitters....we sold a
>bunch of different types of inverters minus SMA and every single brand
>I would get inquires back regarding the discrepancies between the
>"revenue grade meter" and the internal inverter meter......After
>talking to Xantrex, Fronius, and PV Powered they all admitted that
>they did not have a high grade meters in their internals.
>Consistently I got complaints from customers whose customers pointed
>out the difference between revenue grade and inverter meters....very
>frustrating for an installer to try to explain after they just talked
>about all the good stuff on the inverter they are selling....I can't
>remember even one instance where the inverter was more conservative
>than the revenue grade meter.  10% was a common discrepancy.  I still
>haven't heard of any inverter companies addressing this........
>There are many jurisdictions that do not require a seperate revenue
>grade meter and the customer relies on the inverter to self report its
>production........the higher the number the better the inverter
>manufacturer looks.......not exactly a neutral party.....
>
>Revenue grade meter included in the inverter would be a good marketing
>tool......
>
>--
>Sunny Regards,
>Kirpal Khalsa
>NABCEP Certified Solar PV Installer TM
>Renewable Energy Systems
>
>On Tue, May 27, 2008 at 5:10 PM, Peter Parrish
><peter.parrish at calsolareng.com> wrote:
>>
>>  I have a question about the accuracy of the "energy supplied (kWh) total"
>>  for Fronius inverters. Does anyone know how it is spec'd and what are the
>>  numbers?
>>
>>  In the Los Angeles DWP territory, we are required to install a "production
>>  meter" in series with the inverter and we regularly use the GE I70S
>>  "odometer" style meter. We buy these from Austin International and they spec
>>  the accuracy of these meters at +/- 0.3%.
>>
>>  I have been regularly seeing discrepancies of up to 10% difference between
>>  inverters and production meters. Usually, the GE meters read low compared
>>  with the inverter.
>>
>>  For example, we have an IG-5100 which now reads 7,250 kWH and a GE meter
>>  that reads 6,560 kWh. The Fronius came reading 6 kWh, presumably due to
>>  bench burn-in testing. The GE unit came reading 9,999.
>>
>>  Information on the accuracy of the Fronius would be great (because in this
>>  case I have a very puzzled customer); and if anyone is accumulating
>>  statistics on inverters vs. production meters in general I would be
>>  interested in what people are finding out.
>>
>>  - Peter
>>
>>  Peter T. Parrish, Ph.D., President
>>  California Solar Engineering, Inc.
>>  CA Lic. 854779, NABCEP Cert. 031806-26
>>  peter.parrish at calsolareng.com
>>
>>  -----Original Message-----
>>  From: Darryl Thayer [mailto:daryl_solar at yahoo.com]
>>  Sent: Tuesday, May 27, 2008 4:17 PM
>>  To: RE-wrenches at topica.com
>>  Subject: [Norton AntiSpam] Re: Fronius inverters - Reliability?
>>  [RE-wrenches]
>>
>>
>>  Hi Bob
>>  Also look at the PV Powered 1100  if you can go that
>>  small.  I am looking forward to using my first one
>>  later in June.
>>
>>  I have only a few Fronius and had no problems that I
>>  can remember other than one did not wait to grid
>>  reconnect.
>>
>>  Darryl
>>
>>
>>  --- Bob Clark <bclark at solar-wind.us> wrote:
>>
>>>
>>>  Wrenches;
>>>
>>>  Sorry if this topic has been discussed before, but
>>>  the search function would not work on Topica.
>>>
>>>  Fronius IG 2000 (or other Fronius inverters, for
>>>  that matter) - are they reliable? We have heretofore
>>>  used the SMA SB1800U (120V output), but have been
>>>  told by our distributor that it is no longer
>>>  available. Hence the need to consider the Fronius IG
>>  2000.

-- 
Ian Woofenden <ian.woofenden at homepower.com>, Senior Editor, Home Power magazine
Subscriptions: $24.95 per year PO Box 520, Ashland, OR 97520 USA 
800-707-6585 (US), 541-512-0220
or download free sample issue at <http://www.homepower.com>


- - - -
Hosted by Home Power magazine

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

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

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

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

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at re-wrenches.org

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>