Solar Panel wire size and voltage drop calculations


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…

17 thoughts on “Solar Panel wire size and voltage drop calculations”

  1. Watchers beware the information in this video is not correct.

    This video is not approved by the creators of the spreadsheet.

    The creators of the of the spreadsheet have broken your link because of the false? information provided in the video. Please do not relink till the mis-information has been corrected.

  2. 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?

  7. 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.

  8. 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.

  10. I would use the real world temperature of the face of the solar module (60c to 90c) not the STC temp of 25c. For the voltage drop, I would use the Vmp and the Isc. Lowest voltage and highest amps. Something else that is little confusing in the video. With Grid Tie inverters you add voltage in the string and the amps stay the same. Ten 17.4 modules = 174 volts and the amps would be the same as one module 7.75 amps or what ever it was in? the video.

  11. AC voltage is a push and pull not a full circle like DC voltage. So why not use one way wire length, not the full round trip length like with DC voltage??

  13. 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.

  14. 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.

  15. 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.

  16. 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

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