PVWatts Solar Energy Calculator

Based on NREL PVWatts Standard Parameters

DC System Size (kW)

Module Type

Tilt Angle (0° to 90°)

Azimuth (180° = South)

Soiling

Shading

Wiring

Aging

Parameter	Impact on Production
Tilt Angle	In the US, a tilt equal to your latitude (usually 30°–45°) maximizes annual output.
Azimuth	180° (True South) is the “Gold Standard.” West-facing (270°) is often better for late-afternoon peak energy use.
System Losses	Most residential systems lose 14% naturally to heat, wire resistance, and dust.