On 1/17/2012 4:18 PM, benn kilburn wrote:
boB,
If this concept were to become a working option for the Classic, would
the modules have to be modified in any way? Why are the diodes not
blocking the reverse current?
benn
DayStar Renewable Energy Inc.
b...@daystarsolar.ca
780-906-7807
HAVE A SUNNY DAY
No mods. However, as you can see, if the controller is maxed out as far as
array size, that could limit the snow melting effect. I don't have any
hard
data as for the minimum power needed to apply to the array for snow melting,
but it could be around twice the power to melt snow as the power rating of
the array. Yesterday's experiment was less than 2wice the power rating
and it may have been fine with with even less, so that's a very good sign.
How much power does it take to melt snow off of a car's rear window from
the electric defroster ? It's a similar kind thing.
Diodes ?? You mean the bypass diodes ?? No problem. Those don't
conduct in this case.
boB
------------------------------------------------------------------------
Date: Mon, 16 Jan 2012 13:14:36 -0800
From: b...@midnitesolar.com
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] Shedding ice
On 1/16/2012 11:39 AM, David Katz wrote:
Mark,
I believe the Midnite Classic has this feature built in. Check
with them.
David Katz
It just snowed up here in Arlington, Washington A.C. and we were just
starting to melt some snow
on a couple of modules on our roof just now with one of our charge
controllers here in the lab.
This feature is not yet in the Classic, BUT, check out this experiment
that I did about 3 years ago
in my front yard with an animated gif time lapse.
One module is being powered and the other is not powered, just sitting
there for comparison.
These are KC125s.
The time involved here was about 3 hours and took about 1 kW-hour of
energy but gives you
an idea of what may be done with this idea. One thing not in our
favor here is that the module
that is being powered is resting on the ground, in the snow, which
would significantly
hinder snow melting I would think rather than being properly mounted.
Oh what fun it is to melt some PV snow tonight !
http://fusion.midnitesolar.com/PVsnowMelt3.gif
boB
*From*: Mark Dickson [mailto:m...@oasismontana.com]
*Sent*: Monday, January 16, 2012 10:00 AM
*To*: 'RE-wrenches' <re-wrenches@lists.re-wrenches.org>
<mailto:re-wrenches@lists.re-wrenches.org>
*Subject*: [RE-wrenches] Shedding ice
I recall a conversation a while back about the possibility of
"reversing" the current in a solar module to increase the cell
temp enough to shed ice/rime. To follow-up, has anybody been
successful at this? I am guessing, if so, it would entail,
removal of diodes, increasing PV and battery capacity and some way
to sense the ice at the very least. . . It sounds good in theory,
but I am skeptical as to whether it will work in reality. . .
Best regards,
Mark Dickson,
NABCEP Certified Solar PV Installer ^(TM)
Oasis Montana Inc.
_______________________________________________ List sponsored by Home
Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options
& settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out
participant bios: www.members.re-wrenches.org
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options& settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules& etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
