What Is the Best Wire to Use to Install Solar on My Boat?

Question:

I have attached a photo of the wire we have onboard, it reads 12AWG/2 Boat Cable 600 volts. Is this the correct wire for our solar panel installation? - Nancy

Answer:

Thanks for the photo, they always help.  While we could make that cable work, we would not recommend it for your solar install, for a few of reasons:

1. The wire gauge is smaller than typical.  We recommend #10 gauge.  While your 75w panels don’t produce huge currents, depending on the length of the run you will still be experiencing small voltage drops that can definitely reduce the efficiency of your solar charge. 
2. It’s also an issue that the required solar MC4 connectors are designed for #10 wire.  To crimp them onto #12 will offer a less than reliable connection and will not offer a water tight seal at the connection point.
3. The wire in the photo is designed for indoor applications, and is not rated for continued UV exposure.  The white plastic sheathing will eventually break down and crack.

- Jeff