Thanks guys.

I did notice that the MC-4 cable I'm using is 10 ga.

I measured, and the distance comes out to about 25 feet from the solar panel to the charge controller in the garage. Then the cable I have to the Citicar or motorcycle is a 25-footer, but that's already 6 Ga.

One thing I've also never really got my head completely wrapped around is grounding requirements for PV.

I can see there's several grounding points on the panel frame. I guess it makes sense that the frame should go to earth, just because it's up in the air, and there can eventually be a large static charge difference between the frame and the earth.

Do I just need to run a green or bare wire straight from the frame into the ground? I could keep a ground wire INSIDE the conduit, and run it all the way into the garage. From there, it could go to a ground on an electrical box / breaker box, etc, etc.

Any advise? Thanks!

I finished properly mounting the panel today, which included adding extra rafters to the club house, so that there's real strength under where the panel mounts down.

I also mounted a weatherproof box to the end of the peak of the roof, and cut 3/4 plastic conduit, ran it down the side of the playset, dug a trench to the garage, drilled a hole in the wall, to get the power inside. The wires aren't run yet, and I haven't glued the PVC conduit yet either.

I also made some additional cross-bracing for the playset from some 3/4" metal conduit. I pounded the ends flat, drilled a hole in either end, painted them green, and mounted them to the frame.

More photos and videos soon!

-Ben

10 AWG wire should be good for 8 Amps in your system. For the equipment ground, you can run a small green wire, but it needs to connect to an approved ground source at the house. This can be an existing grounding rod, cold water pipe, or grounding lug. You can even tie it to an existing bonding wire with a split bolt.

The grounding cable in the detached garage is exposed and runs pretty close to where the solar power will run into the garage.

I think using a split bolt to run the ground wire to the existing ground sounds like the way to go.

Here's a video update for you.
In it, I show how I added some supports inside the roof and mounted the panel.

Mounting PV to the Solar Swing-Set - YouTube

Blog update on it is on my personal blog as well.
PV installed on Solar Swing-Set

The whole play-set was still a little wiggly, so I made some additional cross-bracing.

Good thing I keep an anvil handy!

http://www.youtube.com/watch?v=2toP6Jy1w98

I got the wiring run inside, and did up the inside with 1/2 metal conduit.

The wiring for the disconnect and solar charge controller are REALLY easy. It's just a red wire and a black wire. From there, I mounted the Anderson disconnect to the plywood just below the solar charge controller with a pair of small wood screws.

The video has all the details, and of course, it has been cloudy weather ever since I got this going! So far, the highest I've charged at is 7 amps. That was with my motorcycle battery pretty much fully discharged and the sun actually peeking out from behind the clouds for a few minutes!

Solar Playset: Inside Wiring & Charging - YouTube

Its been sunny the past few days. How has it been working out?

Any updates on this?

Setup works fine.
The only down side is that it looks like I have bad cells in both the motorcycle and the Citicar, so it never really gets to where it should be with the charging.

I also ordered a 48V 500 watt grid-tie box off eBay. I got that the other day and just rigged it up quick and dirty. I have it hooked up through a KIll-a-watt to track power from it. The highest I've seen so far was about 290 watts, but it hasn't quite been full sun since I hooked it up yet.

I was originally hoping to setup up the C-40 to charge an EV and then swap the output to the grid-tie when the EV is charged, but I think the bad cells will prevent that right now. Also, it required a bit of re-wiring to run in the power diversion mode.

So, for the moment, I'm just running the 48V panel straight to the grid-tie inverter.

I tested, and the anti-islanding feature works well. It's also plugged in through a GFI.

Oh, I also have a full write-up on the project on Instructables.
Solar Swing-Set (PV Playhouse)

The little girl still really likes the bucket-swing and the rock wall and club house, so she's prettty happy. I have the solar panel on the roof, and I think that's pretty cool.
My wife just shakes her head and sighs, but if the little girl is happy, then the wife is happy.