March 13, 20215 yr I've been speccing my solar install for a couple of months have a pretty good idea of what I'm after by now - 8KW Sunsynk with 12 JA Mono Perc and one LiFePo4 battery (type TBC) to start. Now it's figuring out all the non-glamerous details such as required cable runs, panel mountings, breakers, isolators and the like. Anyway, I'll be mounting on an IBR flat roof and would like to tilt the panels 30 degrees, but the moutning systems seem to be roughly the same price as the panels themselves (crazy, I know!). Does anyone have any more realistically priced roof mouting suggestions?
March 13, 20215 yr If space is not an issue then over sizing the pv array ends up cheaper than specialised mounting kit for the optimal angle. I looked into at the time of my install and just decided to add more panels instead as the cost of the mounting system was ridiculous. Mine is on IBR with enough space to for 24kwp of solar panels. It's also not visible if its flat mounted on my carport. If you can weld then you could look at making your own using square tubing making a few triangles at the right angle and mounting these on your IBR roof. Steel working companies could even make them up for you with predrilled holes based on your requirements. Two triangles per panel could work. Something like @Vassenmade to mount his panels against his walls.
March 13, 20215 yr Author 13 minutes ago, Achmat said: If space is not an issue then over sizing the pv array ends up cheaper than specialised mounting kit for the optimal angle. I looked into at the time of my install and just decided to add more panels instead as the cost of the mounting system was ridiculous. Mine is on IBR with enough space to for 24kwp of solar panels. It's also not visible if its flat mounted on my carport. If you can weld then you could look at making your own using square tubing making a few triangles at the right angle and mounting these on your IBR roof. Steel working companies could even make them up for you with predrilled holes based on your requirements. Two triangles per panel could work. Something like @Vassenmade to mount his panels against his walls. How did you fix your panels to the IBR?
March 13, 20215 yr 55 minutes ago, Speedster said: How did you fix your panels to the IBR? Special rails that's raised.
March 13, 20215 yr Author Really nice. I'm going to try find a way to get my panels to at least 15 degrees. There's quite a big gap between flat and 15, but 15 to 30 isn't soooo much.
March 13, 20215 yr 1 hour ago, Speedster said: Really nice. I'm going to try find a way to get my panels to at least 15 degrees. There's quite a big gap between flat and 15, but 15 to 30 isn't soooo much. These bolts are quite long so you could have the one rail higher than the other giving some tilt. One side of the panel would then be higher. I think the most tilt you'll get is probably between 8° to 10°. Not sure if you get the bolts any longer which will allow for more tilt.
April 11, 20242 yr I had 10 panels, portrait mounted at 30 degrees, in two rows on a flat ibr roof. The problem is that the rows were mounted north-facing, so they did not align with the beams under the ibr and last weekend's wind took everything out. We managed to salvage 9 of the panels (one even fell onto tar below but didn't break). Once the mounts started to break free from the roof it was a mess of bending, shearing and loose panels. Now the panels have to be remounted but, obviously, I'm cautious. Firstly, I am worried about the previous mounting 'approach' - there is quite a lot of overhang of panel above the highest point of contact with the mounting structure and,secondly, I don't know how to get more proper anchor points into the wood beams if we go north-facing again. Does anyone have advice on this? Do I need to add cross beams of some sort or rails that are anchored to the beams or should I just drop the north-facing idea and try to mount parallel to the beams? I also have an ibr roof that is now holier than the Vatican that I need to sort too...
April 11, 20242 yr What is the length of the IBR sheets? What is the length of your panels? What inverter?
April 11, 20242 yr 4 hours ago, diplos said: I had 10 panels, portrait mounted at 30 degrees, in two rows on a flat ibr roof. The problem is that the rows were mounted north-facing, so they did not align with the beams under the ibr and last weekend's wind took everything out. We managed to salvage 9 of the panels (one even fell onto tar below but didn't break). Once the mounts started to break free from the roof it was a mess of bending, shearing and loose panels. Now the panels have to be remounted but, obviously, I'm cautious. Firstly, I am worried about the previous mounting 'approach' - there is quite a lot of overhang of panel above the highest point of contact with the mounting structure and,secondly, I don't know how to get more proper anchor points into the wood beams if we go north-facing again. Does anyone have advice on this? Do I need to add cross beams of some sort or rails that are anchored to the beams or should I just drop the north-facing idea and try to mount parallel to the beams? I also have an ibr roof that is now holier than the Vatican that I need to sort too... Your stress point is at the top op the panels. Thus the rail should be closer to the top. You need vertical legs that move away from the panel as close as perpendicular to the panels. Then the mounting bracket needs to be secured to the rafters. If rafters need to be reinforced then add more side by side. The wind is also blocked at the lower end. Try for a gap to be added next try. Rather get a structural engineer to calculate/design brackets and rafters for you. Let them take into account the forces and wind speeds. This is their field of expertise. This once in many years event is what needs to be taken into account. Last point to overrule my thinking out loud. Edited April 11, 20242 yr by Scorp007
April 12, 20242 yr @Achmat, if one rail is mounted higher than the other, then the panels will be under stress when you attach the clamps, as the rails are not at an angle to match the tilt of the panels.
April 12, 20242 yr 51 minutes ago, Tariq said: @Achmat, if one rail is mounted higher than the other, then the panels will be under stress when you attach the clamps, as the rails are not at an angle to match the tilt of the panels. Interesting point. I think I might have some that are higher. Luckily we don't have high winds up here in Gauteng. Even with the storms we had which was nothing to what we recently saw.
April 12, 20242 yr 12 hours ago, Virwat said: What is the length of the IBR sheets? What is the length of your panels? What inverter? Panels JA Solar 550W, 2280mm Deye 8kW IBR, not sure, haven't measured
April 12, 20242 yr Why I ask - Maybe considering laying landscape orientation - with 100mm clearance at bottom of panel? Depending on the actual roof size: MPPT 1 90 Deg. with IBR rib for NNE MPPT 2 In line with IBR rib for NNW
April 12, 20242 yr 22 hours ago, diplos said: Now the panels have to be remounted but, obviously, I'm cautious. Firstly, I am worried about the previous mounting 'approach' - there is quite a lot of overhang of panel above the highest point of contact with the mounting structure and,secondly, I don't know how to get more proper anchor points into the wood beams if we go north-facing again. Does anyone have advice on this? Do I need to add cross beams of some sort or rails that are anchored to the beams or should I just drop the north-facing idea and try to mount parallel to the beams? I also have an ibr roof that is now holier than the Vatican that I need to sort too... 🙂 'holier than the Vatican'..... good one! Don't hesitate to re-inforce the roof structure with additional tie beams that are connected (bolted) to the current roof- and building structure, which would then serve to be the anchoring base for the panel structure. It is of utmost importance that the structure to which the panels will be adhered to, be properly designed, build and affixed in such a way, that the PV panels won't be considered as structural- or stressed members. In other words, stresses are not allowed to be applied to, or induced into a PV panel. Just as important is to mount the panels correctly as per specification of the manufacturer. All panels have specified mounting positions. They have been tested to withstand severe windstorms up to a certain windspeed-if installed correctly. Edited April 12, 20242 yr by CobusK
April 16, 20242 yr Looking at the pictures, there is something important missing on your design. You need to add bracing beams to avoid lateral collapsing of the structure. You can see them in the background of the picture. They tie bottom of one leg to the top of the next one.
May 1, 20242 yr You need better tilt brackets. Those look like the lizard tilt brackets. They are too small and that overhang will cause micro cracks in the panels. I mounted 4 panels on my ibr garage roof. I made 6mm steel plates for the top of the ibr that were the attachment points for the tilt brackets. I used stainless steel threaded rod right through the main roof beams and large washers. I added extra supports to the beams with screws not nails. We once had winds with gusts up to 180kph. Everything survived.
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