“The further north you go the wider the summer to winter sun angle.”
Bob-O. Explain this one to me please. The difference between winter solstice
and summer solstice sun angle is 47 degrees, everywhere on the planet, even in
Hawaii. I suspect that in higher latitudes a lower sun angle means m
re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Tom Elliot
Sent: Tuesday, February 22, 2011 7:46 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Array tilt angle doesn't matter?
“The further north you go the wider the summer to winter sun angle.”
Bob-O.
itude.
From: Tom Elliot
To: RE-wrenches
Sent: Tue, February 22, 2011 8:16:54 PM
Subject: Re: [RE-wrenches] Array tilt angle doesn't matter?
Hmmm, I guess there could be a factor that enters into it due to the curvatu
org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Tom Elliot
Sent: Tuesday, February 22, 2011 7:46 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Array tilt angle doesn't matter?
âThe further north you go the wider the summer to winter sun angle.â
Bob-
The broken record will now repeat himself yet again. Bussbars are the way to
go, not across battery terminals but individual strings connected to a central
positive and negative buss from which the inverter connection then runs. This
allows fusing of each individual connection and also allows
d for Free download on all sorts of unsavory sites,
and you aren't getting a royalty check
Imitation is the sincerest form of flattery, and this list listens to and
appreciates you.
Thanks,
R. Walters
r...@solarray.com
Solar Engineer
On Apr 19, 2011, at 10:16 PM, Tom Elliot wrot
>From a reliability standpoint I would never want to bet the farm on one
>string. All it takes is the failure of one cell and the system is useless
>until it is replaced. Three strings means a cell failure only reduces
>capacity by 33% not 100%. I’ve always thought in off-grid systems it is a
Good on the buss bars Wayne. Using them removes the concerns about multiple
strings and increases redundancy and system stability. You won’t need 4/0
between single strings and the buss bar, you can probably easily use smaller
cable, just size it for the individual string. 4/0 to the inverter
Bob,
I totally understand the concern about multiple strings *if the strings are
connected across the battery bank* as had always been the tradition in off-grid
installations. My own experience with such a bank in my system showed why
when I had a single cell get to near meltdown. I was luck
Not surprised at all about the phone company guy. It was a phone company guy
who read me the riot act that no one in their right minds would ever parallel
battery banks the way PV off-grid systems did and got me to set up my system
with separate strings connected independently to buss bars. Th
Has anyone seen any hard data on systems that use concentrated photovoltaics
such as ZenithSolar http://www.zenithsolar.com/ or Morgan Solar
http://www.morgansolar.com/?
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List Address: RE-wrenches@lists.re-wr
at random angles. I think the insolation tables
for a location give numbers for concentrated solar.
Bruce
Tom Elliot wrote:
Has anyone seen any hard data on systems that use concentrated
photovoltaics such as ZenithSolar http://www.zenithsolar.com/ or
Morgan Solar http:/
Had that arrangement used a buss bar instead of paralleling the bank together
through the batteries that part of it wouldn't have been a problem. I'm still
puzzled by the off-grid community's resistance to designing battery banks the
way large telco banks are designed, using buss bars as parall
MessageI would be very curious to hear THE battery company's, or any battery
company's, interest in warranty on a system where the strings of batteries are
paralleled through a buss bar rather than physically through the bank. The
vulnerability to failure of an off-grid system with only one or
Also the fire in New Jersey was a parallel string case of 12 volt AGMs in
4 or more parallel strings (anybody remember better than I?).
DT
--- On Wed, 12/2/09, Tom Elliot wrote:
From: Tom Elliot
Subject: Re: [RE-wrenches] Strings and series of batteries
To: "RE-wrenches"
Date: We
will start to dump
power into the hot battery and you have thermal runaway, which is always
bad news. But even if you do not go to runaway, you have a temperature
based uneven charging.
--- On Wed, 12/2/09, Tom Elliot wrote:
From: Tom Elliot
Subject: Re: [RE-wrenches] Strings and series o
ual, is it worth the
extra expenses and connections involved?
Here is a little jpg that illustrates both of these questions:
ftp://ftp.re-wrenches.org/pub/bbvscablewcrossties.jpg
Tom Elliot wrote at 02:19 PM 12/2/2009:
Darryl, The process of paralleling through buss bars means attaching each
serial s
end of each string? Is that 8 series strings?
I can certainly see the advantage of being able to easily remove a string
from the system.
But I still do not see how it will treat the individual batteries much
better than using large parallel cable interconnects, which might be
cheaper if the r
It has but the one drawback is there is no bar on this bus...
From: Phil Undercuffler
Sent: Thursday, December 03, 2009 11:46 AM
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] Strings and series of batteries
The Surrette 2v L16 is one single cell built in a case the size of
"If you connect links between all of the positives, and links between all
of the negatives,
to parallel the battery, then the only issue is where you connect the
charge source and/or inverter."
Hugh,
The connection is very easy, if you look at the photos on the page I linked
to the connectio
I would love to see some studies on that Michael. I do know that I saw none
of the supposed problems of paralleling more than just 2 or 3 series strings
and the batteries have lasted far longer than the original L-16s did in a
"traditional" bank even though there are 12 strings paralleled toget
This article in the Cape Cod paper floored me, especially with this quote "It's
really not a big deal," said CEO Barry Cinnamon. "The most dangerous thing is
learning about ladder safety."
http://www.capecodonline.com/apps/pbcs.dll/article?AID=/20091219/NEWS11/912109992
My gut says this will sp
If you have to parallel 4 banks do it through a buss bar, not by
interconnecting cells. A few extra cables is a small price to pay for the
added stability and easier maintenance.
Tom
From: Jeff Oldham
Sent: Tuesday, June 22, 2010 7:14 AM
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [
Dan,
I’ve seen this before and you could take it as a bit of a compliment, though a
backhanded one. I’ve seen this before with other successful commercial sites,
most specifically one called shipmyvehicle.com that is the best worldwide
vehicle shipping service. They were totally hijacked, lik
This has got to be a joke. Has to be from the Onion. Did they have no
physicists in the study or was it just oil company marketing people?
From: Drake
Sent: Saturday, May 24, 2014 1:20 PM
To: RE-wrenches
Subject: [RE-wrenches] Fwd: Halliburton science says solar PV can drain the
sun's ener
We chose not to put any pumps or filters on our Snorkel stove heated cedar tub
and would never choose otherwise for off-grid. Wood heats water faster than
any other fuel and even in the coldest winter the tub can freeze and both tub
and stove survive quite nicely and heat up faster than you’d t
Jay,
Here's a source.
http://www.stormcopperstore.com/index.html
Tom
-Original Message-
From: jay peltz
Sent: Tuesday, January 17, 2012 6:43 AM
To: RE-wrenches
Subject: [RE-wrenches] battery buss bars
Hi All,
Where do I find buss bars for a battery parallel problem?
I've got to
Years ago I had my 15 minutes of fame on the old TechTV network’s show The
Screensavers talking about PV and solar energy and got that question at the end
of the show. I had just looked up that info and remember that while it varies
with manufacturer the numbers for embedded energy recovery for
Anyone have suggestions for solar attic fans that will install on propanel
metal roofing? So far most of what I’ve seen is for shingled roofs.
Tom
From: Jason Szumlanski
Sent: Friday, June 08, 2012 9:18 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] Solar Attic Fans
I heard that works well
I suppose it would be an interesting exercise to do the math but my experience
with very cold groundwater input to a gas on-demand heater (Aquastar) showed
very efficient fuel usage even with the cold water input. It seems that
trying to heat a tank of that cold water with PV, especially if th
Thank you Jeff, for asking the obvious. I've been agog that no one seemed
to think this was a nutty situation for an off-grid home.
T.
- Original Message -
From: Jeff Yago
To: RE-wrenches
Sent: Wednesday, August 20, 2008 10:57 AM
Subject: Re: [RE-wrenches] offgrid system que
Cert. 031806-26
[EMAIL PROTECTED]
--
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Tom Elliot
Sent: Wednesday, August 20, 2008 2:57 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] offgrid system question
Tha
That sounds like the old Infinity32 series that was produced for a short
time a decade ago or so. The ones I saw were 3.2 kw 220v Vanner inverters
coupled with Bobier Infinity 6 control centers based around the old
Omnimeter, 24vdc input. The one I installed years ago was pretty damn
bullet p
Yes it was, and you're right, it is a simple mercury switch, no mppt or
anything else. I rather liked the DC circuits buil into the panel since it
allowed for controlling individual DC circuits. We had two in our house and
thus had separate breakers for our DC well pump and DC pressure pump.
I wonder if that was one of Joe's old test units. I seem to remember seeing
one sitting around his shop with a C-40 in the vicinity.
I don't know about how much of a headache it would be, absent the charge
control problems with the Omnimeter that can be routed around. The unit I
installed was
MessageIs there something that would preclude using a two stage system like
the one I used in my home in Colorado? We had a Shurflo 9600 in the well,
happily pumping against a 65 foot head into a buried 1200 gallon food grade
plastic tank from which we then drew water using a Flowlight booster
Golden Genesis questionOne thing, Golden Genesis was playing around with
cadmium telluride thin film and they made a bunch of them, sending them to
locations all over the world before they decided to cancel production.
There was a huge array of them in an off-grid community west of Golden off
I
Todd,
Excellent points to which I'd add I've been wondering just how well-designed
these off-grid homes are that need generators to be running when the home is
unoccupied for long periods of time. A home that uses that much power with
no one in it is simply badly designed.
Tom
- Origi
The elevation accuracy of commercial GPS units is horrible, I've seen them
off by more than 100 feet and they are not reliable at all for the requested
usage in this instance. Surveyors use GPS units that are accurate in both
horizontal and vertical axis measurements but they use radio frequenc
Looking at Bob-O's original response his peeve was different than his
concern about proper cable use and I share his peeve because a customer
looking to get information from a solar business is going to a consider a
source with the title of "Lead PV Installer" and expect a level of training
and
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