PV panels (in the southern hemisphere) should generally face as north as possible. Usually the roof orientation is the limiting factor as well as shade from vegetation or structures that you don’t have any control over but in general anywhere between NE & NW is optimal.
The pitch of the panel is also usually determined by the roof pitch. Brackets that tilt the panels up or skew the panels around to a different orientation generally look kind of ugly and introduce wind loading issues. You’ll pay extra for them too.
Normal roof pitches are between 15 & 25 degrees which work fine here in SE Qld.
A lot of people think that panels should ideally be pitched at the latitude angle (about 26 degrees on the Sunshine Coast) as this is the angle where the sun is perpendicular to the panels at the March & September equinox i.e. the sun spends half of the year below this angle and half the year higher. This only makes sense if the amount of sunlight was the same in winter as in summer but mainly because the days are longer in summer it’s better to lower the angle of panel pitch to maximise the summer gains.
For a grid-connect system you’re looking to maximise solar generation over the year so a pitch angle of about 10 degrees less than latitude
is what you’re aiming for (but 5 to 10 degrees either side of this doesn’t make a lot of difference when you look at the figures). This assumes the panels face north (-ish).
Of course for a stand-alone solar system (SAPS) you need to work out when you require more energy – winter or summer – and adjust panel pitch accordingly. This can only be decided when you do a detailed energy audit or load analysis of what the proposed SAPS is supposed to run.
It’s also recommended to keep the panel pitch to at least 10 degrees so the rain washes any crud off the panels. If you don’t mind getting up on your roof every so often then maybe this isn’t a big deal if you have a good reason to want to lay your panels flatter than this.
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