Optimal PV panel angle

Hi guys

Can’t place panels on roof, going to need to make frame to fit them against a wall, double story…

realise one option is to simply follow angle of roof, but as I have the option, whats the most optimal angle for south africa?

Due to distance to neighbour going t need to fit them landscape, need to figure out whats the strongest panel I can fit that at the angle does not go over boundary wall which is 1M from house… then see how many I can fit next to each other down my wall. Hoping for 6 min, configure into 2 parallel strings of 3 in series.


For longevity, cost and simplicity it is best to follow the roof angle.
Otherwise, your latitude angle, with some saying your latitude minus two degrees at true North.
There is a fairly broad forgiveness factor.

There could also be the consideration of total system cost, in which you might angle it closer to winter angles than optimal angles over the whole year since you might already have more than enough PV on summer.

good point…
so how would i determine that ?


Take a massive amount of historical data specific to your location and feed it into a specialized model.
For $50 Charlie Landau will do this for you at https://www.solarpaneltilt.com/.
After this exercise, you would have to make specialized brackets, which are initially expensive, costly to maintain and not aesthetically pleasing.
Once mounted though you could sit back secure in the knowledge that you are probably up to 10 % better off in production. Which for 6 panels is just over half a panel’s worth.
Just keep in mind the mounts raise the panels so they cast a longer shadow as well and that you may now not be able to fit 6 panels in the available area.
Having done it both ways I replaced my mounts ( that I only then discovered were failing and wouldn’t have lasted another year), I could fit 4 x more panels on the roof.
As a general rule of thumb, specialized brackets are more secure and worth considering if you are ground mounting panels, they are a PITA on a roof. Follow the roof profile and fit an extra panel or two and you will be far better off.

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