The most efficient tilt for photovoltaic panels in Buffalo, New York at a latitude of 42.9°:
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 35.7°.
If you're planning to change the angle of your photovoltaic panels twice per year, the most efficient angle is 18.9° in summer months and 56.7° in winter months.
If you're planning to change the angle of your photovoltaic panels each season, the most efficient angle is 15.2° in summer months and 62.2° in winter months, and 39.7° in autumn and spring months.