Hi All

I trust that you are all well.

I have the following questions regarding solar panels:

A] What commercial mounting system would be recommended for a corrugated roof or is it better to design and build your own mounting system?

B] When the panels are to be installed on the northern slope of the corrugated roof and the inverters and batteries are to be installed on the southern side of the residence what protection does the cables from the PV panels require to be protected from the elements?

C] Is there an advantage when the PV panels are installed with a space between the roof and the panels of 300 to 600 mm?

D] Is there a disadvantage when the panels are installed as in question C?

E] How can you protect the PV panels against hail damage?

F] Must the PV panels be earthed?

Kind Regards

GerhardK83

43 minutes ago, GerhardK83 said:

A] What commercial mounting system would be recommended for a corrugated roof or is it better to design and build your own mounting system?

Renusol has mountings for corrugates sheets. It does however promote landscape mounting of the panels. 

B] When the panels are to be installed on the northern slope of the corrugated roof and the inverters and batteries are to be installed on the southern side of the residence what protection does the cables from the PV panels require to be protected from the elements?

I found that running them in the roof is much better. If you want to protect them, use steel spraque.  

C] Is there an advantage when the PV panels are installed with a space between the roof and the panels of 300 to 600 mm?

Canadian solar recommend  100mm , but we mount anything between 80 and 120 mm. You have to have a gap for airflow otherwise the panels will get too hot and you will loose effeciency. 

D] Is there a disadvantage when the panels are installed as in question C?

You can create too big a gap and allow wind to get in-between the panels and roof. If your mounting structure is not strong enough , this might create a problem. 

E] How can you protect the PV panels against hail damage?

No way that I am aware off

F] Must the PV panels be earthed?

Yes... 

 

In addition to what Jaco said...

3 hours ago, GerhardK83 said:

A] What commercial mounting system would be recommended for a corrugated roof or is it better to design and build your own mounting system?

There is something you need to be aware of, known as "galvanic corrosion". This is corrosion that occurs because of dissimilar metals in direct contact, with an electrolyte between them (simple moisture in the air is sufficient to serve as electrolyte). This means you cannot put aluminium onto steel, because the steel will rust, the aluminium will get that white powdery crusties, and things just won't go well. If you do build your own frame -- this is something I've actually done both in steel and aluminium -- I would use definitely aluminium instead of steel.

If you must use steel, you need to place rubber strips between the panel and the frame, and whatever you use to bolt it down cannot make contact with the panel itself. It's not worth the effort. Just the amount of time it takes to cut, weld, and paint the steel is more than made up for in aluminium. Just get yourself a set of Renusol rails and mid/end brackets and be done with it 🙂

(When I started in this game, Schletter was the only modular framing system, and the frame cost just as much as the PV modules. Thankfully those days are over...).

3 hours ago, GerhardK83 said:

C] Is there an advantage when the PV panels are installed with a space between the roof and the panels of 300 to 600 mm?

D] Is there a disadvantage when the panels are installed as in question C?

The issue with PV modules on the roof is LIFT. Wind gets under it and it pulls up. If you put them close enough to the roof itself, the envelope is small and the force is limited. But, if you put them too close, they get hot and they don't perform as they should. 300mm is too much, but less than 100mm is too close. You should probably aim for about half the minimum you were thinking of: no more than 150mm. Also, I am not a structural engineer, so my advice may still be wrong 🙂

 

Edited April 27, 20206 yr by plonkster

I use this: golfplaat. If you're interested I can ask if they ship to your country. SA I assume?

10 hours ago, GerhardK83 said:

E] How can you protect the PV panels against hail damage?

Hang'em under the roof. Silly joke... 😊

 

Check this thread on the other forum: https://www.4x4community.co.za/forum/showthread.php/310792-How-to-mount-PV-panels-on-the-roof?p=4086025#post4086025

The honorable Fluffy advises.. 

1 hour ago, Richard Mackay said:

The honorable Fluffy advises.. 

His advice seems good. I believe the "1 meter away form the edge" is overkill. But you must stay away from the edge by at least 300mm or 500mm depending on who you believe 🙂

I hope Schollyboy was joking in that thread... cause that's exactly the kinda cr*p we expect "camping" people to come up with 😂

Edited April 28, 20206 yr by plonkster

Thanks for all the feedback and valuable information @Jaco de Jongh, @plonkster, @RikH, @Richard Mackay.

@RikH Dankie vir die voorstel ek kan hulle ook seker kontak en vra of hulle nie na SA toe uitvoer nie, ek is seker hulle sal Afrikaans verstaan. Die grappie is ook uitstekend.

 

34 minutes ago, GerhardK83 said:

ek is seker hulle sal Afrikaans verstaan

In my ondervinding skakel die Nederlanders oor Engels toe sodra hulle agterkom jy praat nie eintlik hulle taal nie. Maar hulle verstaan wel heel goed. Daar is wel woorde wat hulle nie verstaan nie, soos "baie" (daai het ons geërf by die Maleiers), "sinvol" (by die Britte gekry) en so meer. Waar jy wel na hartelus Afrikaans kan praat is in 'n Restaurant, die kelners geniet dit partykeer. Een het verbaas vir my gesê: Aaah, you're speaking OLD dutch!

14 hours ago, GerhardK83 said:

A] What commercial mounting system would be recommended for a corrugated roof or is it better to design and build your own mounting system?

 

You don't have to reinvent the wheel!

Have a look at Rubicons offerings:

P2000 1mm galv 6m

Araymond Powersnap 90B

Tile Bracket  (If you have a tiled roof)

They sell stacks of this gear so I don't think you'll regret having bought from them.

4 hours ago, GerhardK83 said:

@RikH Dankie vir die voorstel ek kan hulle ook seker kontak en vra of hulle nie na SA toe uitvoer nie

No need to import or buy long rails or nothing, Renusol has got a corrugated sheet solution. You will need the following 4 components. If you need a quote, just tell me how many panels you want to mount. 

 

51 minutes ago, Jaco de Jongh said:

No need to import or buy long rails or nothing, Renusol has got a corrugated sheet solution. You will need the following 4 components. If you need a quote, just tell me how many panels you want to mount. 

 

Thanks @Jaco de Jongh, at this stage I am only doing research after the lock-down then I can start making decisions of how many of what to buy.

4 hours ago, Richard Mackay said:

You don't have to reinvent the wheel!

Have a look at Rubicons offerings:

P2000 1mm galv 6m

Araymond Powersnap 90B

Tile Bracket  (If you have a tiled roof)

They sell stacks of this gear so I don't think you'll regret having bought from them.

Thanks @Richard Mackay

@GerhardK83, dankje voor je reactie in het Afrikaans. Is zo leuk voor ons Nederlanders om te lezen! Ik heb gekeken waar @Jaco de Jongh mee kwam en dat ziet er ook goed uit. And it will save you a lot of hassle when you order it in SA.