[RE-wrenches] Enphase track record

[Mark Frye]

One weakness did present itself to me during my installation of Enphase
inverters. Enphase makes some hay with the "no single point of failure"
topology.
 
However, all the individual inverters share common AC buss wires. These are
built by daisy chaining AC leads from inverter to inverter and then to the
branch circuit.
 
The weakness is that if any single AC Tyco connector connection fails, all
inverters upstream of that connector will be effected.  Sort of gets you
back to the weakness of module to module connections in a string system. 
 
Interesting to me that we can talk much about the life cycle testing of the
inverter, but in this case it all comes back to a connector to connector
connection.
 
So a real question becomes, how will the Tyco connectors hold up over time
in real world applications.
 
Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  
 

  _____  

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Nick Soleil
Sent: Sunday, November 08, 2009 12:19 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Enphase track record


Hello wrenches:
    Enphase is an excellent, reliable product, with many advantages, but a
few minor bugs.  I have managed many Enphase installations, have been
involved in Beta Tests with them, toured the facility, and I have attended
customer feedback sessions with them.  I will give you a quick overview:
        - Being able to monitor individual module output is priceless.
Antony's experience is valid, his problem was related to the bad module.
When I do system testing, I will frequently find module issues related to a
failed string of cells, on one modules.  I think this is a common problem,
which is rarely found.
        - The inverters are very reliable.  I have never had a failure on an
Enphase Inverter or Monitor.  At Enphase, here in Petaluma, they place the
inverters in life-cycle testing beds, which apply continuous 160 degree
temperatures to the units, while placed on a vibrating plate.  
        - I had an inverter communication error once, and called Enphase,
they connected to the monitor and uploaded the softare to it remotely, and
resolved the issue.
        - The monitoring system and Enphase web-based monitoring system is
easy to work with.  Enphase does all the work to set it up for you!  
        - Availability has been extremely tight since late April.  They
really blew it when they discontinued the 175 watt inverter, and ended up
not having any replacement for months.  By then, they were really
back-ordered.
        - They hired a few of the guys who made the technical support at SMA
so great (Kent Sheldon, Marv Dargatz, and others.) 
        - The biggest issue with using Enphase is that communication errors
will occur between the modules and inverters.  Most of the time it is fine,
and the inverters will continue to produce power, but the monitor will lose
connection with 1 or more inverters, and the website will post 0 watts
output for those modules.  Once the communications are restore, the daily
and monthly outputs will be corrected, but the graphs and time-lapse show
will be in-accurate.  This can lead to some customer calls, but the
customers are normally accepting, because it is so impressive, it is easy to
accept the occasional glitch.

 
Nick Soleil
Project Manager
Advanced Alternative Energy Solutions, LLC
PO Box 657
Petaluma, CA 94953
Cell: 707-321-2937
Office: 707-789-9537
Fax: 707-769-9037 


  _____  

From: Nick Vida <nickvida at ymail.com>
To: wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Sat, November 7, 2009 6:04:40 PM
Subject: [RE-wrenches] Enphase track record



I
That's interesting Drake, about the accessible groups. 
Are there clearance issues for thermal concerns or anything?
It sounds like you could run your dc wires up the rows and have
all your inverters grouped on the top rail. That a one man call to
trouble shoot a system which has been a big concern from many voices 
all along. Maybe those guys can offer several whip lengths or something... 
i don't know I haven't worked with the gear yet.

nick vida

 
I'm also concerned about the issues brought up here.  I have two 
possible projects that would benefit from Enphase due to the fact 
that the modules will go on more than one roof, with significantly 
different orientations.  In one case, there are shading issues as well.

Supposedly the Enphase units are selling fast. 

 Someone
 must be 
installing them.  They have been out long enough that there must be 
some data as to whether or not the units are surviving.  The long 
term will not be known until the inverters have been out for many 
years, however if they are having issues in the short term, then we 
know they have issues.

One idea that Enphase tech support said was acceptable was to mount 
the inverters in accessible groups.  The DC leads would need to be 
extended, and some loss would occur.  Also the inverters can be 
mounted in vented attics.  Having the inverters in a group in an 
accessible attic would make maintenance easier than tearing apart an 
array to get to a dead inverter.



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