Minimum angle of roof photovoltaic panels

The optimal tilt angle of photovoltaic solar panels is that the surface of the solar panel faces the Sun perpendicularly. However, the angle of incidence of solar radiation varies during the day and during different times of the year.

In a perfect world (well my perfect world anyway) all roofs would be built at the ideal pitch to maximize solar output. However, as mentioned before, most roofs in Australia are at 15° or 22.5°. So how much solar power are you losing if your panels are not at the perfect tilt angle?

For photovoltaic panels where the electricity is re-injected into the grid for re-sale, the optimum orientation is south with an angle of a 37°, which maximizes total electricity production. With the DualSun PV- T panels, which produce both electricity and hot water, the optimal angle is the same as for PV panels.

In Australia, common roof pitches are 15° or 22.5° – so your modules will most likely be mounted at one of those angles: What if you have a flat roof? If your roof is totally flat, then I strongly recommend mounting the solar panels at an angle of at least 10°. This is really important because it will allow any rain to easily run off the modules.

People who live at locations measuring 35 degrees should usually select 35-degree roof pitches for optimal performance. Dynamic factors throughout the year, together with sun position, change the effectiveness of the recommended angle. Your location's latitude is the primary factor in determining the best roof pitch for solar panels.

South-facing solar panel systems almost always generate the most electricity, but east-west roofs can work well for solar, too. The direction is more important than the angle. Angle is rarely a make-or-break factor, and most roof tilts will work fine—though there are some exceptions.