Acceptable line loss

[idiggplants]

ok, so im adding a solar setup to my remote pavilion... it will run a car radio and a handful of led lights. I dont think ill be using much power at all.

i already have a renogy 100w panel a SolarEpic EPEVER 20A MPPT Solar Charge Controller

I had planned on putting the panel on the roof of the pavilion, which is pretty shaded. It was convenient, and i think it might get the job done... if not, i could add a 2nd or 3rd panel...

but... someone suggested doing a longer run and putting the panels out in the field 125' away which would give it considerably more light. However, this being a budget build, i dont want to spend a fortune on wire. I do have a ton of 12/2 uf wire.. im unsure if the line loss would be acceptable. the way i figure it, as long as im not loosing 50%, id still be getting more energy to the charge controller than the shaded panel. I am aware that i cant have the voltage drop below 14v or there abouts.

when running this line loss calculator, i am unsure what volts and amps to put in for my panel... and im also unsure of what % drop is acceptable, and what end of line voltage is acceptable.

thanks!!!!

[bcroe]

The first things to understand, are that shading may cost you 90% of your output, and also that
hours of good sun are limited. You didn't mention batteries, which I assume would be used.
Get together some real numbers on what the radio and lights will actually use. Runs at 12V
are pretty limited, but by using panels in series with the rated MPPT controller, distance can
be increased an order of magnitude with decent results. Bruce Roe

[Mike90250]

There is a reason they are called Solar Panels, and not Shade Panels. With even small (dime size) spots of shade, their power output drops off dramatically. If you already know the roof is shaded, or even partly shades, it's not suitable for solar

[Sunking]

Batteries have minimum charge current requirements that must be met, or they will soon turn into boat anchors. A 100 watt solar panel, with a good MPPT controller, full sun with no shade obstructions will generate roughly 8 amps into a 12 volt battery. Assuming no shade issues from sunrise to sunset can support a 80 amp hour battery. 8 amps on a 80 amp hour battery is C/10 the recommended charge current.

With your plan in the shade, less than 1 amp and just enough to charge your cell phone battery. In other words will fail.

As to your questions, the panel specs give you the answers. A 100 watt panel Vmp = roughly 18 volts, and Imp = 5.5 amps and keep voltage loss to 3% or less. At 125 feet 1-way will require 4 AWG and 250 feet of 4 AWG will cost you around $200. A 100 Wat panels will support a 60 to 80 Amp hour battery.