Matching Panels and Inverter

[fastbike]

My next issue relates to physical installation of the panels which are 1134 wide. My nephew is going help me on Sunday, he wants $$$ and I want a strong helper
I placed one of the  panels on the floor inside my house and have tried to lean across to see what access is like for tightening the clamp on the far side. There is no access from the far side (6m above ground) so only access is across the panel (see diagram). I am thinking I will make a small kneeler board that transfers the weight to the frame without putting pressure in the glass (a small wooden "fin" to locate it).

The numbers indicate the sequence of placing clamps assuming panel installation moves from left to right, bottom up: for the first panel clamp 1 is accessed from below, clamp 2 from above. 3&4 are unencumbered. For the second panel clamp 5 requires a long reach (the subject of this post), clamp 6 is accessed from above.  As the installation moves across, the clamps 3&4 can be accessed for tightening when the third panel is placed, from below and above respectively. However clamp 7 will be hard to reach when the fourth panel is placed.
How do installers normally do this (and I'm not walking on the panel !)

[nctnico]

I reached across the panels when I did my install. However, I had to to use a ladder to tighten the last two bottom clamps because I couldn't access them from the roof.

[fastbike]

I reached across the panels when I did my install. However, I had to to use a ladder to tighten the last two bottom clamps because I couldn't access them from the roof.

Thanks, are you quite tall ? I've placed a PV panel on the floor and am having trouble reaching across without putting my knee on the frame. I think I will make a small wooden pad that has a "fin" to keep it centred between panels and two fillets to ensure the only point of contact is the frame.
Ladders cannot be used due to the height (roof is 6.5m above ground). I have scaffold at the front, and the rear has a working platform about 1.5m below so access from front and back is fine.

On another note, I washed the (metal) roof yesterday with a roof cleaner product (probably just expensive detergent LoL) and a soft broom, then hosed it down. This is the first time I've done that since it was installed 23 years ago. It is amazing the dirt and debris that was removed, as the only other maintenance I had done was to spray for lichen about 2 years ago with a product containing Benzalkonium chloride. Once the panels are up access will be more difficult, and the areas underneath will no longer be washed by rain, so time for the bird poo to be gone.

It's raining here today but the forecast is for fine weather tomorrow with light winds (<20km/hr) so should be a good productive day for panel installation.

[Siwastaja]

You can put your knee on the frame or even on the glass. Just avoid placing all your weight on a small spot. Many installers do that all the time but there is risk of hidden damage. Leaning over the panel carefully is fine.

You can find the load ratings on the datasheet and calculate how much weight is allowed given a certain surface area.

[nctnico]

I'm quite tall indeed. But I used a socket wrench to tighten the clamps so I didn't need to reach all the way. Just enough to rotate the socket wrench a bit. Being a complete novice where it comes to laying solar panels (*), I didn't want to take any chances with the panels and took my time. I did read some manuals where it was strongly advised not to put any weight on the panels so I followed that advice. There probably is a grey area the professional installers know about intimately but I don't 

* And already strongly regretting doing the solar panel project so much that I don't want to go onto the roof again to mess with the solar panels.

[fastbike]

You can put your knee on the frame or even on the glass. Just avoid placing all your weight on a small spot. Many installers do that all the time but there is risk of hidden damage. Leaning over the panel carefully is fine.

You can find the load ratings on the datasheet and calculate how much weight is allowed given a certain surface area.

Wasn't going to risk it (panel is rated at 5400Pa, I'm 100kg/1kN, spread that over 10cmx10cm, and you're at a loading way over what the panels can withstand) , so I made a small "kneeler", just a piece of 4x2 timber a bit longer than the width of the panel with two equal angle 20x20x3 alloy pieces screwed to it at each end and some tape to stop it scratching/slipping. I could place it across the panel to reach the tricky clamp and get it torqued down.
Where there's a will there's a way

[fastbike]

I'm quite tall indeed. But I used a socket wrench to tighten the clamps so I didn't need to reach all the way. Just enough to rotate the socket wrench a bit. Being a complete novice where it comes to laying solar panels (*), I didn't want to take any chances with the panels and took my time. I did read some manuals where it was strongly advised not to put any weight on the panels so I followed that advice. There probably is a grey area the professional installers know about intimately but I don't 

We got all 27 panels installed, mainly following the plan I'd drawn up for the sequence to avoid issues trying to get access. I had a 22 nephew help me and he got the hang of attaching cable clips and routing the 1200mm long leads. For the row in portrait mode at the bottom we ran the leads down to the bottom so they could be connected after all panels were installed. For the upper portrait row the leads ran up the panel so could be connected at the top after placement. The panels at the outside of each 5x2 "block" had one lead up and one down so they could connect to the other row. The terminations to the home run cables for each block are at the inside edge (adjacent to roof window), with all leads running up.
I left  a small (~25cm) access gap between the middle and top row which is 7 panels running in landscape mode so we alternated the panels here (+ve up, then +ve down) so the connections either ran along the bottom or the top, keeping the +ve lead always pointing left so this took a bit more figuring out.
The installer said to attach clips before we got on the roof so we did this on the scaffold where we could eyeball the location.
I'd preinstalled conduit with draw wires so this is now ready for the installer to come and do his magic sometime this week ready for the inverter which is two weeks away.
This is what it looks like on the house ...

And of course because I ordered a pallet of 36 and only used 27 on the house, I now have a "problem" of 9 spare panels. I've checked in with my wife and will order another 5 panels so I can fit 14 to the garage. This gets some shade which moves across the panels depending on time and season which would wreck the output of a string inverter so will look at optimisers or micro inverters for this.

And already strongly regretting doing the solar panel project so much that I don't want to go onto the roof again to mess with the solar panels.

Sorry to hear that, I've quite enjoyed it so far. A bit frustrated at times but a good opportunity to learn something new, and a challenge to get my fitness/upper body strength up a bit. It's 23 years since I was up on the roof when we built (I put the roof on with my Dad and father -in-law). Also I'm luck that the steepest part of the roof is less than 30 degrees and because it is curved it is only about 10 at the top so relatively easy to work on.
My nephew asked why we did not install solar PV when we built the house LoL. I had to explain that this system would have cost approx $100k back then so would never have been economic as power prices were 50% of current, so would have taken about 60 years for cash break even ignoring ROI. For comparison the full cost (excl garage) will be approx $15k, which I've modelled has a 5 year cash payback period, slightly longer if time value of money is included.

[nctnico]

The scaffolding is nice. Makes access easier! I have two big windows on the roof (35 degree slope) and I used those for roof access as I found using my ladder would be a bit iffy.

[fastbike]

The scaffolding is nice. Makes access easier! I have two big windows on the roof (35 degree slope) and I used those for roof access as I found using my ladder would be a bit iffy.

It would be very hard without the scaffold. I erected it myself using 3 "H" frames and then tube/clip style stuff. We have rules here that anything with a working platform over 5m has to be installed by certified installers, I am under that limit so could do the work myself which saves a heap as the weekly hire is very cheap - the delivery/install/remove is the expensive part.
Yes, ladders are not good for carrying stuff up, you probably can't see but the ladder for the scaffold is attached at the top and then tied in at the bottom to make it super stable.

As an aside, I was up on the roof and a neighbour called out to talk. Her husband had been up on their (steel) roof the previous week, water blasting the lichen off - which by the way does not fix the problem as the roots will still be there and it regrows. I asked if he had a harness, the answer was no. So I asked if he had life insurance, and the answer was still no. Crikey, sounds like a widow making activity