Solar panel question

For you guys who have experience with solar systems,are your panels hooked up in series or parallel,I'm gonna have 2 panels to start off with,some where in the ball park of 300w with a 30amp victron mppt controller

One factor that helps you decide this is whether or not there will be partial shading of the solar array. If wired in series, shade on one part of a panel will affect the entire array, whereas a parallel arrangement would allow the unshaded panel(s) to yield their maximum output.

Another consideration is the voltage of the bank that you're charging. If wiring in series the voltage is additive, which can allow lower voltage panels to charge a battery bank with a higher voltage. It also gives the advantage of allowing a lighter wire gauge. Parallel wiring, by contrast, will yield a lower voltage but will give higher amperage; this requires larger wire, which can add up to significant cost.

What's best on one boat will not necessarily apply to another.

Sabre hit the high points. In my case shading wasn't a problem but trying to fish heavy gauge wires from the bridge to the engine room was. I ended up using series panels that provided 70 volts and 10 gauge wire to the controller located next to the battery bank.

My charge controller will be mounted about 2ft away from house bank that it will be charging

Normally for a small installation, run in series. This allows higher voltage and smaller cable runs. If partial shading will be an issue or if the panels are mounted on different plans so their angle to the sun will be different, run on two separate MPPT controllers

Peter

Good advice above, can't add any further .

David

Other thing to consider is redundancy. We set up our panels to be independent of each other. Each had its own controller, heat dump for when batteries fully charged and independent wiring throughout. That way if one (or more) panels failed the rest would function. That’s important if you’re going to be off grid for any length of time or on a mooring with the boat unattended for a considerable length of time as well.

If the panels are at exactly the same angle, they can share a controller. If they're high voltage panels (VOC of 30+ volts), series vs parallel won't matter too much in a lot of cases. If they're lower voltage, definitely put them in series.



Personally, for my install of 2x 410w panels, I'm going with 2 separate controllers (1 per panel). Cost for 2 smaller controllers vs 1 big one is about the same in my case, and the panels are going to be at slightly different angles due to deck camber. So the 2 controllers may give slightly better output.