Hey everyone! I'm setting up a 12v solar system in my cabin and I'm planning to relocate my solar panels to a new spot that's about 150 feet from my charge controller. I have four 200w, 12v panels, and I'm considering using a boost converter to raise the voltage to either 48v or 60v to reduce losses during the wire run. My controller can handle voltages from 12v to 60v, so that's a plus. Should I be using the output voltage of my panels (around 19v) for calculating line loss when deciding on wire gauge, or does it need to be based off the 12v? Also, is it worth converting the output to AC right at the panels and sending that back to the cabin instead? Any recommendations for a reliable boost converter would also be really appreciated!
4 Answers
Before making changes, double-check what kind of converter you have! If your converter like mine (a Renogy model) can take 24 volts in, then wiring two panels in series for 24v and leaving the other two parallel is an option. For your run length, switching to a 48-volt converter might be worth it, or you could consider using 120v AC for that long stretch.
You might want to consider wiring two panels in series, which gives you about 38v (19v x 2). Then, if you parallel the two pairs, you'll get 34v, which should work pretty well for your run. Just make sure you use the right gauge wire for that distance to minimize loss. There’s a cool voltage drop calculator you can use [here](https://www.calculator.net/voltage-drop-calculator.html). Just a heads up, if you wire all four in series, you’ll hit 72v, which could be too much for your controller!
Yeah, I agree! Series wiring really helps with voltage drop. Just make sure your equipment can handle it.
Just a heads-up, if you wire all four panels in parallel, you might lose a lot more power than running them in series. My calculations show that running in series could result in about 4% loss, while parallel could lead to around 64% loss. If you go with series, your voltage will approximate 72V, which should make your run more efficient than converting to AC right at the panels!
Yeah, that’s a significant difference. Series makes way more sense for long runs!
Definitely look for a voltage drop calculator to figure out the right cable size to avoid power loss on your run. Honestly, considering changing to new standard residential panels and a charge controller that handles higher voltages may save you time and money. For reference, I had to use 2 AWG for only a 30-foot run to push 25-30 amps! I found a handy app for Android called Voltage Drop by Southwire that could help you out.
Good point! A higher voltage system reduces losses and could save you trouble in the long run.