Don,
PV:WATTS version 1 is easiest to use and it is available at
http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/. It covers fixed
tilt, single- and two-axis tracking for standard crystalline silicon
modules. My confusion had to do with whether the 5.9 kWh/m2/day was a fixed
tilt value
Michael,
So how many times do they have to replace the modules to get 10% more
energy;-)
Bill.
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Michael
Welch
Sent: Tuesday, November 04, 2008 9:54 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] crystalli
oting member.
Bill Brooks.
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Michael
Welch
Sent: Wednesday, November 05, 2008 10:46 AM
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Fwd: 2011 NEC PV SUBMISSIONS
Hi gang, received this from John Wiles <[EMAIL P
Jerry,
As pointed out below, this is a load-side bus connection. It would follow
the 120% rule if using the 2008 NEC. Since the guy is buddies with the
inspector that should be no problem. However, you must follow the 2008 NEC
if you want to apply it (tap must be at the opposite end of the bus
Carl,
The standard for the loading on buildings, by area in the U.S., is ASCE
7-05. It covers wind loads, snow loads, and seismic loads. Many
micro-climate regions are handled by the local building department for wind
and snow loads.
Bill.
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTE
Folks,
I'm a bit sour on SS ties. These are easy to overtighten and have caused
numerous ground faults in the field. My recommendation is to use
UV-resistant black wire ties and install 2-3 times as many as necessary.
Sure some will fail over time, but we are much less likely to have ground
faults
Chris,
I'm not saying that UV black wire ties are best. I still think that
stainless cable clips made by Wiley are probably the best option of all.
Wire ties, or your solution, should be used when cable clips can't work.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenche
Peter and Darryl,
The right way to do this is using a computer program PVSYST ($800). It will
calculate the operating voltage of each string and the overall performance.
Not much else out there can calculate it. That being said, the loss of these
two orientations will be less than 2% based on the
Peter,
You are wrong about Vmp being a function of irradiance. It is a function of
temperature and remains unchanged from 100 to 1000W/m^2/.
Max power trackers look at the product of Volts and amps. The dithering
routines can vary dramatically from company to company.
Bill.
-Original Messa
Peter,
The more you work with IV curves, the better you will understand them. Since
most people don't get the opportunity to use an IV curve tester, the
understanding of the curves may need some help. As you pointed out in your
"constant temperature" information below, it showed the MPP to be 2 vo
All,
There are lots of problems with the facts of this article. The biggest
problem is that people will read it and believe it. We have our work cut out
on the training side of things. I am personally working with fire fighters
and the solar industry to put together some "Myth Buster" style tests
They are new and cylindrical.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bob Clark
Sent: Tuesday, January 06, 2009 6:31 AM
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Solyndra so
William and all,
I notified a friend of mine in the fire service about this, and he has
followed up with the website to have the article removed. Here is the thread
with me and the website:
Note to me:
This article is exactly the same as one I received from a young firefighter
from Orange Count
Peter,
Where do you read the 50% diversity? My 2005 NEC handbook clearly says that
the raceway adjustment table is based on NO diversity--all conductors loaded
at maximum.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrench
All,
Here is the refuting post by my friend Matt Paiss of the San Jose Fire
Department. Our thanks go out to him for his responsiveness. It is now
posted on the homepage of www.FireFighterCloseCalls.com
FIREFIGHTING AND SOLAR PANELS: FACT VS FICTION
URL: http://firefighterclosecalls.com/fullstor
c.
820 Cynthia Ave., Los Angeles, CA 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779,
NABCEP Cert. 031806-26 peter.parr...@calsolareng.com
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On B
Peter,
No--is that short enough.
Imax is defined by 690.8(A). Imax is the value used for doing all conditions
of use calculations including temperature corrections, conduit fill, and
sunlight impact.
The overcurrent protection device (OCPD) must be sized to 125% of Imax for
continuous operation
All,
This message from Matt Paiss shows that the message is getting out:
Bill,
Not only did it go on their homepage, but it got sent out on what they call
their "Secret List", which is not really very secret, as it has a subscriber
base of somewhere near 100,000. Needless to say, my inbox, cell
Ryan,
I agree with Roy, if you install the PV system on that cast iron pipe,
without any engineering to back it up, you might as well pull out a pistol
and shoot yourself today and get it over with. Unless the wind never blows
where you live, another hole needs to be bored and a the correct Sch
Wrenches,
Thanks to the wind-sun folks for sharing this fire story. There is a lot of
conjecture in the thread, and much of it is wrong. With all due respect to
Solar-Guppy, PV module encapsulant, EVA, is highly flammable, and tedlar
will burn as well. The good news is that there is not a lot o
Wrenches,
After looking more closely at the pictures, it appears that they may not be
glass-covered modules. Given the poor manufacturing practices, this was a
fire waiting to happen the moment they turned it on.
The amazing thing is that the installer is going to reinstall the module-and
b
Marco,
Is 100V the absolute floor, or is it the normal operating voltage. I believe
the Power-One inverter can go down to 90V.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Marco
Sent: Wednesday, F
I'll be teaching Thursday afternoon and Friday morning. See you there.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of David
Palumbo
Sent: Wednesday, February 11, 2009 7:51 PM
To: RE-wrenches
Subject:
Ryan and Matt,
There are significant efforts underway to standardize permitting. Too many
efforts are going on that will cause a proliferation of different ideas,
rather than standardization. The ICC Tri-Chapter document is good, as it is
based on the SMUD document, but it falls significantly shor
ll require more documentation, but a standardized
permit package would eliminate a lot of Building & Safety Departments'
ambiguous subjectivity.
Best regards,
Joel Davidson
----- Original Message -
From: "Bill Brooks"
To: "'RE-wrenches'"
Sent: Wednesday,
Drake,
The size of the GEC is limited by the grounding electrode system. Keep that
in mind since that normally limits the size of the GEC dramatically.
Bill.
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of
Jeff,
Although some of what you say is true-and anyone allowed to install SunPower
modules should be intimately aware of the positive grounding
requirement-they actually can be installed on ungrounded and bi-polar arrays
with the inclusion of some wiz-bang depolizerinators ;-).
Bottom line
Joel,
My understanding is that some of the manufacturers are able to cut so thin
with current wire saws that the cells become flexible--almost like paper. It
presents other concerns, but these newer technologies might actually be
solving some of the cracking problems of the past. It is a brave new
Keith,
Since it seems quite quiet on this subject, I have to ask why a SHARP guy
like you would consider such a rounded or Solindrical technology. Actually,
I have heard through the grape vine that their products have an interesting
performance characteristic in that their output looks similar
Peter,
Although last time we discussed, you didn't seem to agree with me, I guess
I'll try responding to this question.
The best situation is to keep the two strings of modules in their own
strings. 7 of the older in series, paralleled with the 7 of the newer in
series. The operating voltages, an
A 90065
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parr...@calsolareng.com
-Original Message-
From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Bill Brooks
Sent: Mon
Kingsley,
The concern I have about this unit, and many other inexpensive ones like it, is
that it does not have enough resolution in the low impedance area. PV arrays
can have an impedance to ground of as low as 2kOhms. A resolution of 0.1MOhms
will likely not cut it. I just bought a $175 me
August,
A very annoying aspect of this manufacturer's brochure is that the cute bar
graph has a fairly large error. What the heck does "Daily Average Power
Generation" mean. I think they mean energy. Just a nit-picky pet peeve of
mine that we see too often in the energy world.
The data on t
Doug,
That is why I made the comment that their panels tend to be underrated (a
good and rare thing). One of the reasons is due to the article that Joel
posted a link to earlier (the Japanese govt. hammered them for overrating).
The product has not been on the market (or even in existence) long en
It's just a pity that our solar system only has a single sun. This product
was really built for a 2-sun solar system. It is nice to have a module that
looks good from underneath. That is probably the biggest benefit. To claim
any improvement other than aesthetics is difficult. I have seen data that
Geoff, Daryl, and others,
To be clear, Sanyo's product is not an amorphous-silicon (a-Si) product. It
has a-Si coatings that help with the electron flow at the surface of the
cell. There is no reason to believe that the Staebler-Wronski effect, so
well known over the past 30 years, has any impact
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