That is not my experience with all of the xanbus model AES. Maybe the
ones from 2018? All of the others will shut down the contactor and you
will lose inverter to protect from charging at temps below 32F. There
will be plenty of warnings and a fault event into the Conext Cloud
devices or SCP.
Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail offgridso...@sti.net
text 209 813 0060
On 2022-12-04 7:49 am, Bradley Bassett via RE-wrenches wrote:
If they are the AES 48-6650 batteries I think they do not have low
temperature mode, and will be damaged if they are charged while they
are below freezing. The AES 48-3000 I think do have a low temperature
mode and would prevent charging if they are below freezing.
Wind will tend to make any object closer to the ambient temperature,
unless there is evaporation involved. So, if there is radiation to the
sky making the object colder, the wind will warm it. If there is solar
radiation making it warmer, wind will cool it off. Warm animal bodies
of course will be cooled by wind if the ambient temperature is below
body temperature, and cooled even more by evaporation.
Brad
On Sun, Dec 4, 2022 at 7:01 AM Dana Orzel via RE-wrenches
<re-wrenches@lists.re-wrenches.org> wrote:
Dual - Discoverer LI battery bank not sure on battery mode setting
(written down but cannot locate at the moment) & no backup generator.
Very conservative & minimalist client. I over designed past his energy
load evaluation request on purpose as he did not want to have to use a
generator.
He has built the entire house off of 2 - small 12 volt PV systems &
battery charging cordless tools. Living on site in the garage...
I am very impressed with his commitment to low impact & not a
wackadoodle or survivalist either. Excellent classical, bluegrass, &
jazz cellist.
Dana Orzel - E - d...@solarwork.com - C - 208.721.7003
From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf
Of Mac Lewis via RE-wrenches
Sent: Sunday, December 4, 2022 7:41 AM
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Cc: Mac Lewis <maclew...@gmail.com>
Subject: Re: [RE-wrenches] Sola-ark cold morning
Hi Dana,
What type of batteries? What battery mode?
If you have Lithium batteries with communication enabled, there are
certain modes that the BMS is running the charging show. I've seen the
Sol-Ark throttle back charge as instructed by the BMS under these
circumstances.
A quick check of this would be to start the generator and see if it's
on the battery management side or PV only side.
It seems like you are way below the MPPT upper limit if Im looking at
the correct QCell spec sheet.
As far as the temperature theory. You can have temps on surfaces below
ambient. This can happen in two ways that I am aware of: radiation and
evaporation. The radiation effect occurs because the cold night sky
(very cold) is exchanging heat with a surface. This is why you can get
ice on lakes above 32F. It's very complex to model this but I doubt
you could come close to lowering the temperature far enough to drive
the Voc out of the MPP range.
Also, there will be competing heat exchange trying to drive that
temperature back to ambient. For example if you had a lot of wind in a
clear cold night, the convection heat exchange from the wind would
actually warm up the surface.
Evaporation (or any phase change) can drop an object's temperature
below ambient as well. It will pull latent thermal energy from objects
in order to change the phase of the molecules. This actually has a
stabilizing effect on temperature typically because it takes a lot of
energy to change phase. This is why people use large water barrels in
greenhouses to release latent energy to prevent freezing.
Please let us know what you find out.
Thanks!
On Sun, Dec 4, 2022 at 6:22 AM Dana Orzel via RE-wrenches
<re-wrenches@lists.re-wrenches.org> wrote:
Hey Now All Wise ones!
An of gird client emailed yesterday that his Solark had been accepting
only 350 watts of a 4KW input from the array. The modules are Q-cell
325 watt 2 strings of 7 modules.
Sunrise, full sun, no clouds so no edge of cloud effect, negative temps
@ -6˚F, he waited all day with no improvement or change in the charge
rate consistent 350watts input & then same thing next morning. Negative
temps & full sun & 350watts solar input.
He turned the Solark off for 10 minutes & then turned it back on & 4KW
charge input returned. The Solark did not turn off or deliver any alarm
or warning.
My initial thought was over-voltage spike, we designed for a -25˚F
scenario & 110 PSF snow load. Beefy!
I did not ask if it was windy additionally. Could this contribute to a
colder array temp? I have always been of the impression that wind chill
did not affect metal or glass that it has to do with moisture being
driven off.
Thoughts & suggestions?
Dana Orzel Great Solar Works, Inc.
C - 208.721.7003 d...@solarwork.com
Idaho Contractor - # 028765 Idaho PV # 028374
www.greatsolarworks.com [1] www.solarwor.com [2]
"Responsible Technologies for Responsible People since 1988"
P Please consider the environment before printing this email.
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
--
Mac Lewis
"Yo solo sé que no sé nada." -Sócrates
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
Links:
------
[1] http://www.greatsolarworks.com/
[2] http://www.solarwor.com
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
