All,
In the spirit of full disclosure, I work for Conergy in applications
engineering, and we're distributors of CSI modules. (Michael, I hope I'm not
out of line commenting from this perspective).
Keep in mind that CSI (Canadian Solar Inc.) is one of several manufacturers
selling modules with cells made from "solar grade silicon" or Upgraded
Metallurgical Grade" (UMG) silicon. UMG is a less refined product than
polysilicon (not to be confused with "polycrystalline"), from which the
standard monocrystalline and polycrystalline cells are produced. Cells produced
from UMG silicon are known to have greater levels of impurities, which lead to
a greater degree of charge recombination within the cell -meaning fewer
electrons make it out of the cell to do work. Consequently, the cells have a
lower power/unit area output. This is why some of the CSI modules have lower
power output per unit area than comparably sized modules.
CSI also makes modules using cells produced from polysilicon, and these modules
have power densities comparable to other polysilicon-cell modules.
Here's the rub with CSI: Both lines of modules -the UMG line and the
Polysilicon line, use the same basic model numbers. The CS6P line of modules
uses 60 6" square cells. The UMG cell modules are referred to as "e modules" in
the CSI literature. Typically, the CS6P modules in the 160 - 200 watt range
will be the e-modules, and the CS6P models from 200 - 230 W are the polysilicon
modules. It's best to look at Canadian Solar's web site to figure out which
module you're actually looking at. CSI has had some labeling issues, too, which
has caused some consternation for folks using the e-modules in CA under the CSI
rebate program. I understand that CSI is addressing the problem.
What I've seen of and read about UMG modules (including the CSI e-modules)
suggests that there are some issues with UMG that must be addressed in order to
use it as a PV cell material. Apparently, the purification processes for UMG
are proprietary to the various processors making the raw materials, and making
cells from UMG silicon is also a touchy process that's closely held by those
making them. The types and levels of impurities vary, so purification is a
moving target, and it's difficult to get a consistent product. From what I've
read, UMG, because of the impurities, degrades somewhat quickly initially, then
stabilizes and should remain predictably stable over the life of the module.
This is reflected by CSI in their module warranty for the e-modules, which is
comparable to other polysilicon modules. It is known that, due to the
impurities, back-currents in UMG cells can lead to hot spots. UMG modules are
less shade tolerant as a consequence. In the case of the CSI e-mod
ules, the j-box is loaded with diodes -5, if my memory serves me. The reason
is that there are fewer cells in each string within the module that's protected
by a bypass diode. This is the manufacturer's way of dealing to some degree
with the shade intolerance. Other module manufacturers, from what I read, are
less forthright about their use of UMG cells -to their credit, CSI does not
obfuscate the fact that they have a product line that uses UMG.
I've been somewhat skeptical of UMG modules and have withheld judgement of the
CSI e-modules, waiting for field results. I have but a fraction of the
experience of many among this august group, and I have no need to promote
product for Conergy or anybody else. What I have seen so far, among the few
systems I'm monitoring, is that the CSI modules are performing to spec, and
aren't failing to any significant degree. That said, the CSI e-module is
intended to be a lower cost product -that's the presumed niche for UMG in the
first place. Time will tell if UMG and other less expensive technologies are
worth the money saved.
I hope this information is somewhat helpful. Caveat emptor. Further!
Dan Rice
Conergy and
Abundant Sun (solar) (-Bill, I got your acronym already...)
--- penobscotso...@midmaine.com wrote:
From: penobscotso...@midmaine.com
To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Canadian Solar modules
Date: Thu, 15 Oct 2009 16:53:49 -0400 (EDT)
We have installed about 20k of these modules, largely off grid. I
would make these recommendations:
Install on good quality mounting. We have almost exclusively been
installing these on DP&W top of pole mounts. The frames are not
particularly beefy but they are not flimsy, either, and a good mounting
system should compensate. That said, we will not use them in our Caribbean
installations due to hurricane potential.
Install where the people have plenty of room. As Tump said, these things
are doors (39 5/8 x 64 or so), but when our customers have more room than
money we install them. We installed some CSI 200's yesterday and today
installed an array of Sanyo 195's and the difference was pretty
obvious.....
CSI panels have met the same specs and pass muster other manufacturers
have had to to achieve UL approval. They are not for everyone I
suspect, but they are meeting a niche market, are UL approved and I
think are a decent product. Perhaps in a few years I'll feel
differently but the ones we have in the field are performing well and
have been through some big winds without issues. As I said, time will
tell.......
Daryl DeJoy
Penobscot Solar Design
> "Canadian" Solar modules are most definitely made in China.
>
>
>
> I guess they couldn't get away with branding "American Solar" and probably
> didn't want "Mexican Solar." Heck, everyone likes Canadians. The "Strong
> frame" is not very rigid and flexes too much like most Chinese modules.
>
> ----- Original Message -----
>
> From: Bob-O Schultze <mailto:bo...@electronconnection.com>
>
> To: RE-wrenches <mailto:re-wrenches@lists.re-wrenches.org>
>
> Sent: Thursday, October 15, 2009 7:48 AM
>
> Subject: Re: [RE-wrenches] Canadian Solar modules
>
>
>
> Holt,
>
> No experience with them, but I believe they are made in China. The whole
> misnomer of "Canadian Solar" is enough to turn me off to them.
>
> Bob-O
>
>
>
> On Oct 15, 2009, at 7:31 AM, <hol...@sbcglobal.net> <hol...@sbcglobal.net>
> wrote:
>
>
>
>
>
> Greatly valuing the opinions of all who participate on this list, I was
> wondering if anyone has had experience with Canadian Solar modules. Am
> bidding a 42kw system for local community college, so budgets are tight
> and
> this line of modules fits the budgetary profile. Sharing pros or cons
> would
> be greatly appreciated.
>
> _______________________________________________
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