Photovoltaic (PV)

Photovoltaic names an effect, not a product. A semiconductor cell releases electrons when light hits it, and that flow is direct current. Wire cells into a module, modules into strings, run the output through an inverter, and you get the alternating current your panel feeds. So when a builder's contract says solar, ask which kind. PV makes power. A solar thermal collector only heats water.

What limits an Arizona array is roof geometry and firefighter access, not sunlight. Scottsdale publishes placement guidelines that decide your review lane: panels at least 3 feet below the ridge, two 3-foot-wide access pathways from eave to ridge on each roof slope, and 18 inches off a hip or valley where panels sit on both sides. Meet all three and the permit gets a fast small-scope review. Miss one, or go ground-mounted, and the same house lands in full plan review.

Height and tilt work the same way. On a south-facing pitched roof, the top of the panels stays within 8 inches of the roof surface. On a north, east, or west facing roof, tilt stays under 15 degrees and height under 24 inches. On a low-slope roof, 30 inches. An array with dead loads over 50 pounds at the mounting points needs a structural analysis.

The array is its own permit next to the house permit. In unincorporated Maricopa County a rooftop system files as a minor residential electrical permit, and the county's automated code check, SolarAPP+, does not stand in for it: "This step does not issue a building permit."

For example, an owner tilts a west-facing array to 20 degrees to chase winter production, breaks both the 15-degree and the 24-inch limit, and trades a quick review for a full one. If an HOA is the obstacle instead, A.R.S. 33-1816 bars it from banning a solar device outright, and any placement rule it writes cannot raise your cost or cut the system's output.