Solar hobby shed (kid project)

[Mr Gus]

Trying to find info for a person I don't particularly know (pub)
They recently bought some solar (ebay presumably) unused small panels "possibly" as little as 10 watts per panel, maybe 20 / 30 watts , still small)
likely sub 600 watts as a rule of thumb total

Their plan is to make a solar roof (no gaps) as a powered protective layer (luckily good solar facing) from a shed so it is useful as kid grows & can be re-purposed to a dad shed, the idea being the kid can hobby model with a light & soldering iron? / charge a tamiya rc battery pack or two "type thing" led light inside, solar light (not connected outside)
Kids dad has access to lots of leisure batteries.

As far as I could ascertain, panels to be one entity, mounted with air space 6 inches? with multiple edge supports across the outside edge affixed to the shed walls, I advised fine mesh for squirrel proofing / nesting issue mitigation.

I mentioned galvanic corrosion down the line so he is inclined to reduce risk & get it right from the outset (good on him) but likely wants to do it once.

What may I suggest for..

A. panel screws (connecting multiples together)
B. waterproof seal (for between sandwiched aluminium frames) to increase shed roof longevity.
C. well priced (ie recommended buying source)
D. any hobby shed solar resources you have bookmarked (perchance)

I've already mentioned air flow beneath panels etc, I think he wants to get a gist of coverage & power potential to match up a battery that will be used more in summer than winter before he assesses mounting, however he did say there are enough to overhang the pent roof & provide shade & trap cool shadowed air.

Shed already has good exterior cowled ventilation as it is used as dry storage (both ends)

Wi-fi already reaches that area, so kid can carry a tablet if needed.
Insulated shed (polystyrene or better) assumed no heating needs.
Lighting strip to be a 15 watt led strip & a close proximity 5 watt led work light.
soldering iron (30 watts) .. portable battery radio (usb charging)

Shed use is really therefore bench space for an RC car / other model hobby work.

[Stinsy]

I'd make the roof out of 19mm OSB3, cover in roofing felt, then screw the panels to it.

You could bolt the panels together with silicone sealant acting as a gasket but you'd need a lot of rafters because each panel would need to be supported by two rafters.

The electrical bit is the easy part. First figure out what the characteristics of the panels are and how many. I guess they are something like this:

https://www.bimblesolar.com/solar/small ... olar-panel

Then he'd need a charge controller to sit between the solar and the batteries. This is a good one:

https://www.bimblesolar.com/victron-sma ... 0a-12v-48v

Plenty of cheaper options, beware of eBay/Amazon quality charge controllers, most are terrible and they're often mislabeled. Don't worry about having a lower power MPPT than panel power. I'd suggest a 24V battery system as the best compromise. You say he has access to loads of leisure batteries, I'd warn about having too large a pack of very-old batteries because the self-discharge could become significant.

Lastly he'll need an inverter. These are easy enough to come by. Just get a "pure sine wave" one that is at least 2x the power you think he'll need.

[Mr Gus]

Solar charger is sorted, I found him a solid small unit.
Pent roof is sturdy.
It needs to be raised off the other foot & connected to the side walls so no holes in pre existing roof) concerns being "water finds a way in" & potential leaks tacked from side wall screws are easier to tackle & less likely.

In essence regard it as no roof contact at this point, support needed would be support blocks chemically fixed (no holes) in contact with shed roof but screwed to panels. to keep panel structure raised yet rigid.

By access to leisure batteries, I mean he can take his pick & get a good deal on appropriate size to roof potential, have mentioned the obvious, but fixing technique eludes me, he wants it neater than sticking softwood pallets on his shed roof & sticking panels on them, but it's a good point to envisage.

Really it's joining small panels as watertight as possible with a non botch screwing together due to no rails involved metallurgical reaction to cause problems down the line.
After that the obvious need for a plethora of decent (not fake) connectors to be obtained & a reel of decent solar approved cable.

[Stinsy]

Aluminium and Steel don't like each other. However galvanised fixings solves this, the problems mainly occur when you mix stainless steel and aluminium.

[Mr Gus]

OK galv fixings it is.
unless there are freely available bung protectors maybe? (in need of investigation)

So is silicone still on the table for waterproofing the frames? what's its lifespan in full on sun / weather?

Any specialist silicone to consider? one with a high uv resistance?

Rubber strips down the adjoining edges, screwed together then a silicone layer to max out rigidity & proofing?

[Fintray]

To fasten the panels together just use aluminium nuts and bolts as they do for aluminium greenhouses.

[Mr Gus]

That makes perfect sense Fintray ...that also completely eluded me! (damn it)..thanks! i'm kicking myself.

Any recommended well priced source for alu nuts n' bolts?

[Fintray]

That makes perfect sense Fintray ...that also completely eluded me! (damn it)..thanks! i'm kicking myself.

Any recommended well priced source for alu nuts n' bolts?

Just have a look around the neighbourhood as it's very likely there will be a glassless aluminium greenhouse sitting forlornly in someone's back garden just begging to be dismantled and taken away for free. Drop of Loctite threadlock as they are fitted and should be fine.

Or look on Amazon, plenty to choose from.

[Mr Gus]

Thanks Fintray.

like a dolt I read "small" to mean the panels in question, had side to side profile bolt holes to them, but apparently they are big enough to be standard bottom profile for a normal rail system, which throws things a bit.

I don't like the idea of carving out screw holes in the side of the frames & weakening a structure (potentially)

Thoughts?