Ask PYS: Power

Can I Add A Solar Panel To My Existing Array?, on Oct 03, 2017 asked:

Can I add a solar panel to my existing solar array? I have a 100W solar panel and a GV-10 solar controller installed on my boat. Can I add another panel without running a second set of wires? -Heidi

 

If you are connecting multiple solar panels, you have a few options, parallel, series or a combination of the two.  A parallel circuit has multiple paths so if the circuit is broken, the current will continue along the other paths.  This is how most houses are wired (ie if you turn out the lights, the TV stays on).  In a parallel circuit the voltage remains the same however the amps are added.  If you have 3 solar panels that are 10 amps at 12 volts then the entire array will be 30 amps at 12 volts.

A series circuit has one path so if the circuit is broken, no current will continue.  This is how most old Christmas lights were wired so that when one bulb burns out, the whole string stops working.  In a series circuit the voltage is added and the amps remain the same.  If you have 3 solar panels that are 10 amps at 12 volts then the entire array will be 10 amps at 36 volts.

The only one that will allow you to add a solar panel without installing an additional set of wires is parallel.  -Jeff