The most efficient tilt for photovoltaic panels in Glendale, Arizona at a latitude of 33.58°:
Your photovoltaic panels need to be angled facing south.
If you're mounting the photovoltaic panels at a stationary angle, such as on your roof, the most efficient angle is 28.6°.
If you're planning to change the angle of your photovoltaic panels twice per year, the most efficient angle is 10.2° in summer months and 48.6° in winter months.
If you're planning to change the angle of your photovoltaic panels each season, the most efficient angle is 6.6° in summer months and 53.9° in winter months, and 30.6° in autumn and spring months.