Glossary
Azimuth
Azimuth is the angle that tells which compass direction a surface faces, measured in degrees clockwise from north (0°): 90° is east, 180° is south, 270° is west. In the northern hemisphere, a roof with an azimuth near 180° (south) receives the most sun over the year; east and west produce somewhat less, and north is the worst orientation.
What azimuth is
A panel produces more when the sun hits it head-on. Because the sun crosses the sky from east to west through the south, a south-facing surface has it head-on for the most hours. That direction is expressed as an azimuth of 180°. A roof at 90° faces east and produces mostly in the morning; at 270° it faces west and produces in the afternoon.
Azimuth combines with tilt (the roof’s angle from horizontal). Together they determine how many kWh per year each installed kW generates. Design software runs that calculation for each roof slope.
Why it matters in Florida
Florida sits far enough south that the sun rides high most of the year, which makes the penalty for not facing exactly south smaller than in northern states. An east- or west-facing roof is still viable. West has a practical advantage too: it produces in the afternoon, when the air conditioner works hardest, and if your utility offers a time-of-use rate it lines up with the expensive hours.
What does hurt is north. A salesperson who puts panels on the north slope to “fill out the system” is adding kW that produce little. Check that the proposal shows production for each panel group separately.
Common mistake
Accepting that “the roof is perfect” without seeing the azimuth of each slope in the proposal. Ask for the layout with orientation and tilt for each array, and the estimated production of each. If one array produces far less per installed kW than another, ask why it is there. In how many solar panels do I need in Florida we explain how it affects system size.
Full guide: How many solar panels do I need in Florida? Sizing from your real kWh →
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