Model step
Incidence-angle modifier, diffuse and albedo
Reflection loss of sky diffuse and ground-reflected irradiance
Inputs used: Plane tilt, GCR (ground cover ratio)
What it is
The incidence-angle curve is defined for one direction, but the diffuse light arrives from the whole sky and the ground. This step selects how the curve is averaged over those directions to give one factor for the sky light and one for the ground-reflected light.
Options
- Mask-conditioned integrals: the curve integrated over the part of the sky the rows leave visible
- 19-bin histogram: 5° incidence-angle bins of the sky and the ground, each weighted by its share of the light on the plane
- Effective angle: one effective angle for the sky and one for the ground
References
- Brandemuehl & Beckman 1980, Transmission of diffuse radiation through CPC and flat plate collector glazings, Solar Energy 24(5) 511–513
API
iam.diffuse_integration = conditioned_integral | histogram | effective_aoi