April 16, 20224 yr I am really new at this solar stuff and having installed a Sunsynk 5.5kw inverter about a month ago I thought it would be a good idea to add some solar panels. Being a bit of a handyman, and always looking for new projects around my house, I thought this would be a breeze. Needless to say, it was not as easy as I thought and being a absolute newbie, the biggest problem I faced was where to find sound advice and information. From the actual installation of the roof hooks and rails to what I would have thought was simple stuff like the distance between rook hooks (along the length of the rail) and and how far apart (top to bottom) the rails should be etc. was a nightmare trying to find the correct imformation. I visited so many stores and tried to search Youtube as well as this forum. Someone also told me that I must I also cut the roof tiles and I remember telling myself - what on earth is this bloke talking about. Anyway, with the little bit of information that I could find, I went about installing the roof hooks and rails and thought I would share what I did - perhaps someone else may find it useful (or possibly others may be able to tell me if I did something wrong). I was advised that the roof hooks have to be between 1m and 1.5m between each hook. Considering your roof rafters are about 750mm-800mm apart, I suppose the 1.5m width seams accurate with a hook on every 2nd rafter. Someone did tell me you need a hook on every rafter (every 800mm), but the cost of doing it this way would be huge if you consider a roof hook costs between R150-R200 per hook. (A 6m lenth rail would then require 7-8 hooks totaling between R1050 and R1600 just for the roof Hooks - then add a 6m rail and the total could easily be around R2K to fit each rail which just seams over the top. So I went with 5 hooks over a 5.5m length with a gap between 1m and 1.5m. I also added in an extra hook on 2 of the rails just because it made me feel better 🙂 . Below is the final installation of the rails. I hope someone will find this info useful or perhaps if I did something wrong someone could tell me before I fit the actual panels. Edited April 16, 20224 yr by Marcodp Posted before I was finished compiling the post
April 16, 20224 yr Author The one thing that I could not find was the correct Gap between the rails - as per the pictures you can see that the bottom rail has a gap of 1m between the 2 rails while the top 2 rails have a gap of 1.2m. Im not sure which is correct and would appreciate it if anyone can advise what the correct gap is or if they are both fine?
April 18, 20224 yr I used similar spacing to what in your photo but with only 4 roof hooks per rail (2 per 3.3m rail), and to date 2 years 3 months later its still ok. You may want to check if your panels will fit in portrait mode, mine are 2 m x 1m in size, if your tiles are 30 cm each, space may be tight unless you mount the bottom ones in landscape mode. The shade in the bottom section is also not good as it will negatively impact on performance of your panels, if possible rather move the panels away from the shade. In theory there is a benefit to maximise the angle of the panels to the horisontal, maximise the adjustment of the bracket at the top and minimise it at the bottom, could give you a couple of extra degrees...
May 17, 20224 yr Author Thank you for the confirmation/info BGb as this was a question 🙂. Re the positioning, I considered placing them horizontally so to minimise the effect of the shade at the bottom, but the roof is not long enough for when I eventaully get to install my full compliment of panels (16). I managed to fit the initial 10 and although the shade (from the chimney) does impact me, it is not causing me to much of an issue due to the time of the day - it will also only be really evident in Winter months as the sun seams to be lower and it moves over the panels in the afternoon from right to left. As mentioned, I was limited by what I can do as I still need to add the last 6 x panels (3 x top & 3 x bottom) in the gap where the rails are still protruding which takes up all the roof space I had left. After installing the current 10x375w Canadian Mono panels (3750w), I have been able to generate between 2000-3000w on an average May day (with clear skies) which is the start of winter in CPT and from what I have been told, this is relatively good/ok. I am also fortunate that my afternoon consumption is relatively small So far so good 😀
May 18, 20224 yr Great job Marco, pretty sure you enjoyed a few beers after this job. It's back breaking....
July 10, 20223 yr @Marcodp Thank you for sharing. First, the mounting position on panels. This picture is for JASolar 365 - 390W Panels (just to illustrate the principle): The vertical mounting hole sets are spaced 1150 and 1400mm apart. I understand that the ideal clamping position is between these sets of holes (along green lines). On to the shadow. Learn from my mistake, as I mounted my panels too close to my solar geyser. During the winter months, it casts a shadow on the closest two or three panels (depending on time of day), affecting performance of the entire string. Yesterday I moved those three panels out of the shade. Here are the results between yesterday and today (both days: clear blue skies): Excuse the readability, but I resized one graph to show equal vertical scales. Orange line shows 3kW. The winter's reduced power generation from having a roof inclined at 15-20 degrees is nowhere near the reduction in performance due to shading. Today the batteries were full just after 1pm, whereas yesterday charging was still underway at 4pm when I disconnected for the relocation (mains charging required). Peak power of a string of 9*455W on one MPPT has increased by ((4.63-3.31)/3.31 😃 40% just due to removing the partial shadow (similar in extent to your chimney's) from 3 panels. Before moving the panels, I may have been better off just disconnecting 2 or 3 panels. (If you want to try that yourself during the day, just remember to disconnect the breaker feeding DC to the inverter before disconnecting the cables at the panels.)
October 5, 20223 yr Author On 2022/06/02 at 2:49 PM, 18650 said: This looks awesome, well done. Is this a grid tied system? Yes it is, which came with its own complications (make/model of inverter, ensuring no feedback to the Grid etc.) and based on Cape Town, I had to consider the City's requirements which was an interesting challenge by itself 🙂, fortunately they (City of Cape Town) has everything published on their website which did help.
October 5, 20223 yr Author On 2022/05/18 at 7:27 AM, Steve87 said: Great job Marco, pretty sure you enjoyed a few beers after this job. It's back breaking.... It was 🙂 and you had better believe I had more than a few 🙂 - I must be honest in that it was a lot more work than I originally anticipated and my back hurt for a week 🙂
October 5, 20223 yr Author On 2022/05/18 at 5:32 AM, BryanOC6 said: Thank you for the info, great work! Thanks, I hope it was useful? I have now added the additional 6 panels (now totaling 6000w) and have managed to generate 5300w on some sunny days during the winter months in CPT, which I think is awesome - cannot wait to see what I am able to geberate during the summer months 🙂
October 5, 20223 yr Author On 2022/07/08 at 12:46 PM, DIYjohan said: Marco. Thanks for sharing . Big help to me Awesome, I am glad it was useful - I really struggled to find good/useful/accurate info before I started on this project so am really please this helped.
October 5, 20223 yr Nice to see how you did that. 15 Years ago I would also have done it myself, now I no longer climb on roofs! 5 300 wats seems good going, best I've seen on my system is 4.7 W (10 X 640 panels) this winter, also CT.
October 5, 20223 yr Nice job. This also speaks to the matter of how much an install is worth. R150 a hook 😮 And then that not so light labour.
February 5, 20233 yr An absolutely fantastic post. I thoroughly enjoyed the journey ... that lays in front of me.
February 5, 20233 yr On 2022/04/16 at 6:08 PM, Marcodp said: I was advised that the roof hooks have to be between 1m and 1.5m between each hook. Considering your roof rafters are about 750mm-800mm apart, I suppose the 1.5m width seams accurate with a hook on every 2nd rafter. Someone did tell me you need a hook on every rafter (every 800mm), but the cost of doing it this way would be huge if you consider a roof hook costs between R150-R200 per hook. (A 6m lenth rail would then require 7-8 hooks totaling between R1050 and R1600 just for the roof Hooks - then add a 6m rail and the total could easily be around R2K to fit each rail which just seams over the top. So I went with 5 hooks over a 5.5m length with a gap between 1m and 1.5m. I also added in an extra hook on 2 of the rails just because it made me feel better Anyone knows the recommended spacing between roof hooks?
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