What are System Losses and why are they important?

System losses are an important factor when estimating solar system generation.  

Typical Categories of Losses:

Irradiance Based Losses: Tilt, Azimuth, Shading, Soiling, Snow Loads, Incident Angle

DC Based Losses: Nameplate Rating, Weather, LID, Voltage Mismatch, Wiring Losses

AC Based Losses: DC/AC conversion, Inverter Clipping

Other Losses: System Degradation, System Availability (uptime %)