[RE-wrenches] larger off-grid system inverter preference

[North Texas Renewable Energy Inc]

Howie
I installed 2 of the early 4248 SIs with 4 2500Us feeding thru the pair. 
Some minor programming glitch during setup was addressed with a new chipset 
from SMA and the system has worked without problems ever since. I'm 
fortunate that the ranch manager at the facility was helping with the entire 
installation and is capable of monitoring the system as needed.
If he's happy, I'm happy.
I know of twice that the grid failed, within the first 6 months of 
operation, and the entire system worked flawlesly. Yes the price is high but 
the reliability appears to be typical of SMA products.

my 3 cts [after inflation]
Jim Duncan
North Texas Renewable Energy Inc
817.917.0527
ntrei at earthlink.net
www.ntrei.com

----- Original Message ----- 
From: "Howie Michaelson" <howie at suncatchervt.com>
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Sent: Wednesday, March 04, 2009 11:47 PM
Subject: [RE-wrenches] larger off-grid system inverter preference


Hi all,

Seems large off-grid systems are happening more frequently.  Like most, I
spend a lot of time trying to get my clients to lower their loads wherever
possible, explaining the benefits of doing so from a financial as well as
environmental perspective.

None-the-less, I am currently designing an off-grid system for a primary
residence which will likely have about 10kW solar and either one 48 volt
2,400 amphr string or 2 48 volt 1,800 amphr strings.  The peak load will
be perhaps 8,000 Watts. and consumption of perhaps 25 to 40 kWh/day
(summer to winter).  The remaining load will be made up by generator, and
maybe eventually wind (they wanted to put a vertical access turbine on
their "barn"/garage roof, which I am still actively discouraging, but they
like the look...).  This is the largest off-grid system I have designed to
date.

I'm leaning toward using 2 SI 5048's, but not having used SI's before, I
am wondering about 4 OB VFX3648's (since I'm quite familiar with them).  I
like the sophistication and options (and I believe better charging
efficiency) of the the SI's, but would be interested in feedback from
others experience.

Thanks as always,
Howie
-- 
Howie Michaelson
NABCEP Certified Solar PV InstallerT

Sun Catcher, LLC
Renewable Energy Systems Sales and Service
VT Solar & Wind Incentive Program Partner
http://www.SunCatcherVT.com
(cell) 802-272-0004
(home) 802-439-6096




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