Panel Orientation

verdigo

I'm getting ready to buy and mount my last four panels. Maybe. I currently have four on my shed roof that are fixed at latitude and four on a ground mount that is adjustable at latitude for summer and latitude minus 15 degrees for winter with all pointed due south.

I am trying to decide if I should aim the last four south west to gain a little more of the afternoon sun on a another fixed mount that is adjustable for elevation, or a pole mount that is adjustable for elevation and direction.

These are pretty large 300 watt panels and we get some pretty strong winds from thunder storms from time to time. Can anyone recommend a pole mount that is sturdy enough to support what will amount to 173 sq ft of PV at 200 pounds?

Would I be better off to just point them south like the others? There won't be any shading issues, and all three arrays will be connected to the same combiner/charge controller (Classic 150)

Thanks
Dennis

tmarch

Re: Panel Orientation

I use pole mounts for my well pump installs and I like the DPW mounts the best of those I've used, but they are more expensive. I install my modules in pairs because that prevents a lot of wind load problems on too big a "sail". It's also less expensive to run a small amount of wire than a bigger pole for mounting. Realistically if I install any additional modules on my home system I will look at pole mounts for snow removal.

verdigo

Re: Panel Orientation

I like the IronRidge stuff but their sizing tool doesn't like my Renogy mounting holes though they are physically the same size as the Grape panels that do work.

jebatty

Re: Panel Orientation

With experience from your existing panels, what do you find on morning vs afternoon production? Where I live morning typically are less cloudy than afternoons when clouds frequently roll in, only to clear again in late afternoon. Also, mornings are cooler with higher production. I am very pleased with my due south mount, but I think a do over would be a mount at 160-170 degrees.

BB.

Re: Panel Orientation

You can go to PV Watts and get the hourly production (average or typical day based on the a 20 year cycle or so). It is actual measured results so you can play around and see what works best for your area.

For me, in summer, my net metering plan is about 3x payback for noon-6pm on weekdays. I keep my power usage low, and I get 3x credit for summer afternoon production that I can use off peak/winter time. So I have a very strong bias for westerly facing panels (my home's roof, on the other hand, faces southeast--So that does bias me for morning production).

We had one poster here (Solar Guppy) that did a lot of testing in Florida--For him, southwest facing panels gave him more energy harvest. Afternoon heat (depressed Vmp-array) and afternoon thunder showers would depress his harvest.

-Bill

verdigo

Re: Panel Orientation

jebatty wrote: »

With experience from your existing panels, what do you find on morning vs afternoon production? Where I live morning typically are less cloudy than afternoons when clouds frequently roll in, only to clear again in late afternoon. Also, mornings are cooler with higher production. I am very pleased with my due south mount, but I think a do over would be a mount at 160-170 degrees.

Southeast would probably give me some shading issues unless I build the mount around a 100 feet away. As for morning or evening clouds I will do as BB suggests and take a look at PV Watts.