[RE-wrenches] Inverters and cold temps?

[Ryan J LeBlanc]

Hi Jesse,

Good open question....here's what I think about this problem....

We all understand that electrical components have very clear performance
versus cost trade-offs.  

I think extreme outside conditions, like those below -40°C temps, simply
lend themselves to a string/central PV topology better than a micro
topology. All inverters will always have limitations that when exceeded can
cause product failures.  In extreme conditions, in critical applications, it
makes much more sense to put your critical components somewhere protected
from the elements.  Almost anywhere but behind the module.

Obviously with micro, the inverter is exposed to the absolute worst
conditions possible, that the local climate has to offer.  While with string
or central, you can locate these inverters inside a climate controlled
space... Power sheds, Barn's and Garages are very common.  Networking and
monitoring equipment usually have limitations far sooner than the inverter
these days, so complicated monitoring like Emphases' may also be risky here.
The integrated Display Screens on string inverters can be conveniently
located to make regular checkups a snap.  

It isn't cost effective to design -60°C components into global products
where a majority of units will sell into areas with -25°C lows, when price
competition exists.  So inverters will come in a variety of shapes, sizes
and capabilities, we simply have to use the right tool for the job.  Not
just try to use micro for everything.  Learn how to string, it's fun, and
faster by far.  

If all Enphase has is a hammer, everything they see is nails.  Use the best
product for the project, an easily located string inverter tends to work
real well once you get the "hang" of it.

RL 




Message: 10
Date: Mon, 16 Jan 2012 18:21:17 -0600
From: Jesse Dahl <dahlsolar at gmail.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Subject: [RE-wrenches] Inverters and cold temps?
Message-ID: <B75D8A32-DD4F-403A-8AFE-8DC6CA337E9B at gmail.com>
Content-Type: text/plain;	charset=us-ascii

All,

I live in an area where -40F is not uncommon and where -60F has been seen.
(northern MN)  I have yet to see an inverter that can be placed in locations
like this and not exceed the warranty temp extremes.  

Enphase has a cold temp acceptability of  -40F last time I checked, and when
I called they told me about an install in Antarctica using micros.  

I have installed inverters outside in the twin cities, not up here.  

What do you think about this problem?

Thanks as always,

Jesse

Sent from my iPhone

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