The amount of electricity (measured in kilowatt-hours, or kWh) produced by any solar system depends on two factors: The size (or “power rating") of the system measured in kilowatts direct current (kW-DC); and the amount of sunlight the system receives. The amount of sunlight a solar system receives depends on several factors, including:
- Geographic location (e.g., Phoenix receives more sunlight on average than Seattle)
- Orientation (e.g., roof pitch or compass direction)
- Shading (e.g., from chimneys, trees or neighboring buildings)