Simple spreadsheet to help you optimize your solar PV system using the properly sized wires. Spreadsheet is here: (Right click Save Target as) http://www.oyn…
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Video Rating: 4 / 5
Mar
07
Solar Panel wire size and voltage drop calculations
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Gary H says:
March 7, 2015 at 12:51 am (UTC 0)
When you are talking about feet,are you refering to the distance from the
panel to the charge controller?
adamvalhalla says:
March 7, 2015 at 1:05 am (UTC 0)
I just downloaded the went to the link above and it got me a spreadsheet
saying they don’t endorse you using their spreadsheet, but they give a link
to the true spreadsheet. However, that new spreadsheet has the panel volt
column password protected. Just an FYI to anyone out there.
MySchizo Buddy says:
March 7, 2015 at 1:45 am (UTC 0)
where does this 3% requirement come from
MBA RAO says:
March 7, 2015 at 2:39 am (UTC 0)
great
Jeff Barr says:
March 7, 2015 at 3:07 am (UTC 0)
Looks like the people at the link are unhappy with you for posting this?
The link takes you to a small rant page but they do link to the correct
page for the spreadsheet. Wonder why they are not happy with you doing
this?
carultch says:
March 7, 2015 at 3:40 am (UTC 0)
I thought you were supposed to keep track of voltage drop, using 75C as a
basis for wire resistance, due to the wire’s own heating during
operation. Since most terminals are current-rated at 75C, this provides
you with an upper limit for wire resistance.
mehedi hasan says:
March 7, 2015 at 4:35 am (UTC 0)
hey hey! Have you ever tried – Maxim Earth 4 Energy (google it)? Ive heard
some super things about it and my mother got excellent results with it.
Fearlessthinker says:
March 7, 2015 at 5:25 am (UTC 0)
@helloman1976 Higher voltage from the panels definitely saved you a bunch
of loss. Glad it worked for you. Make sure to use UL 4703 wire outside.
Azad slemani says:
March 7, 2015 at 6:02 am (UTC 0)
thanks alot very helpful
Shady Abeid says:
March 7, 2015 at 6:54 am (UTC 0)
Very Very Helpful Thanks a ton
helloman1976 says:
March 7, 2015 at 7:36 am (UTC 0)
@Fearlessthinker Yes it did and I’m super happy I could go with a higher
voltage, all compliments of my MPPT charge controller. With the MPPT
controllers you always want to be above your battery bank voltage to take
full advantage of the MPPT functions and in this setting I always will be.
Now, I just have to run the rest of the wiring and mount the panels and
we’re all set.
dirt4b says:
March 7, 2015 at 7:48 am (UTC 0)
thanks for the info. right now im using 6/2 5 or 6 strand copper,going 30
ft. from G.T.I. to solar panels. can i do better than that? i need to get
it out of the elements somehow. thanks.
Dimitri Pappas says:
March 7, 2015 at 8:04 am (UTC 0)
Mind elaborating on which information is incorrect? Is it just the
temperature and Vmp/Isc issue? Because apart from that I am happy to use
this Fearlessthinker’s video as a closest reference, because there is not
much else out there when it comes to solar cable sizing, especially not on
youtube
Roger Hill says:
March 7, 2015 at 8:25 am (UTC 0)
Great video, very informative!!! God Bless YOU!
trailkeeper says:
March 7, 2015 at 8:26 am (UTC 0)
This is useful for people making homemade solar electric systems.
dirt4b says:
March 7, 2015 at 8:33 am (UTC 0)
in your opinion which would be the best wire to use. tinned copper, regular
bare copper?
butopiatoo says:
March 7, 2015 at 9:31 am (UTC 0)
with microinverters being used these days at 240v it would really be
helpful to update this. I have a system that is producing .9*6=5.4amps 2
240v and it is so different I’m not even sure if i’m in the ballpark based
on you example. Gret video, but needs to be updated.
Eoin Callaghan says:
March 7, 2015 at 10:23 am (UTC 0)
Thanks for the info, very informative. i was hoping to use the spreadsheet
but it doesn’t seem to be available on that website anymore, would you have
a copy you could send me?
jwright650 says:
March 7, 2015 at 10:43 am (UTC 0)
Thanks for sharing..helps a bunch
helloman1976 says:
March 7, 2015 at 10:48 am (UTC 0)
I just used this spreadsheet, very cool man thanks a ton for finding this!
I’ll be using 160 feet of #6 and then about 2 feet of #4 so I’m at 1.04847V
drop or 1.87308%. 🙂 Need a higher resolution than that? LOL
Fearlessthinker says:
March 7, 2015 at 11:09 am (UTC 0)
Tinned is great stuff but expensive and is really aimed at marine use (salt
environments) as copper does corrode if untreated in such conditions.
Unless you are on a yatch or on the beach, copper solar wire (UL 4703) is
the standard for PV. It has a UV protected sleeve and the #10 can handle up
to 30 amps.
Glenn Hough says:
March 7, 2015 at 11:34 am (UTC 0)
Just what I needed.. glad I watch it.. useful!
OBXSOLWIND says:
March 7, 2015 at 11:49 am (UTC 0)
Great VIDEO I am glad to see a vid that adreses wire size and grounding.
CHEERS
Kevin Johnston says:
March 7, 2015 at 12:39 pm (UTC 0)
No need for hail protection. They have withstood golffball size hail with
no damage
Kevin Johnston says:
March 7, 2015 at 12:46 pm (UTC 0)
i used a had held grinder with a cutting wheel.
Jack Bishop says:
March 7, 2015 at 1:27 pm (UTC 0)
Thank You! This video has helped me so much and i was wondering if i could
(or should) use the series method for linking 3 X 3.65 Volt solar panels.
Im going to have a +5V Fixed-Voltage Regulator that will charge a usb port.
Im kinda new to this so i dont expect anything ive just said to be right!
🙂 please help me soon, im going on holidays and need to make a decision on
buying parts 🙂 Thanks again
caperguy1 says:
March 7, 2015 at 1:55 pm (UTC 0)
Hi again Kevin may I ask what your panels and controller cost .
zipfizzdave says:
March 7, 2015 at 2:41 pm (UTC 0)
I just wanted to thank you for all the videos:) I am installing five 40
volt 220 watt panels a 30 amp mppt controller and a bank of five 75 amp
hour agm batteries on an Amerigo cabover that I will be living in while I
start building an off the grid earthbag house in Mexico. Your videos
straightforward delivery and easy to follow directions are one of the
reasons I have decided to go on this adventure and try to help others by
example with some of my own inventions. Thank you.
whisperingsage says:
March 7, 2015 at 2:46 pm (UTC 0)
I have some Kyocera panels from 1993, and they also say 16 + volts on the
back, but when I check the output with a meter, they usually say they are
producing 17-18 volts. The voltage will change even when you check ac
voltage in household wiring. There is some flexibility there.
Chris Cote says:
March 7, 2015 at 3:18 pm (UTC 0)
Hey Kevin give me a shout. Chris_cote2000@yahoo.com
justinbimmerman says:
March 7, 2015 at 3:54 pm (UTC 0)
Might be a stupid question.. But why ground the panels to the trailer? I
realize the actual mounts might have paint between them causing a very
resistive connection. I assume when you say the “trailer” it is a trailer
on wheels and even hooked to a vehicle wont actually have a earth ground
(insulated by the tires) I guess if lightning strike it would jump from the
wheel to the ground but I’m pretty sure it would fry the panels before it
made it that far. This is one of my concerns for home systm
Mark Player says:
March 7, 2015 at 4:50 pm (UTC 0)
Do you have some sort of hail shield for the solar panels?
Kevin Johnston says:
March 7, 2015 at 5:33 pm (UTC 0)
Panels were about $550 Canadian each Controller was about $300 plus
wire/mounts misc. $200?
field16 says:
March 7, 2015 at 6:10 pm (UTC 0)
I am in the process of mounting a panel and am deciding on my final design.
You do an awesome job of explaining all the steps and you are very helpful.
I may go with aluminum extrusion, too. What tool did you use to cut the
aluminum? Thanks!