modelDiffusePerez

Hemispherical diffuse irradiation on a tilted surface using Perez's anisotropic sky model

Extends from Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation (Partial model that is used to compute the direct and diffuse solar irradiation).

Information

This component computes the hemispherical diffuse irradiation on a tilted surface using an anisotropic sky model proposed by Perez. For a definition of the parameters, see the User's Guide.

References

  • P. Ineichen, R. Perez and R. Seals (1987). The Importance of Correct Albedo Determination for Adequately Modeling Energy Received by Tilted Surface, Solar Energy, 39(4): 301-305.
  • R. Perez, R. Seals, P. Ineichen, R. Stewart and D. Menicucci (1987). A New Simplified Version of the Perez Diffuse Irradiance Model for Tilted Surface, Solar Energy, 39(3): 221-231.
  • R. Perez, P. Ineichen, R. Seals, J. Michalsky and R. Stewart (1990). Modeling Dyalight Availability and Irradiance Componets From Direct and Global Irradiance, Solar Energy, 44(5):271-289.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.Angletil (from PartialSolarIrradiation)Surface tilt
Realrho0.2Ground reflectance
Modelica.Units.SI.AngleaziSurface azimuth
BooleanoutSkyConfalseOutput contribution of diffuse irradiation from sky
BooleanoutGroConfalseOutput contribution of diffuse irradiation from ground

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealOutputH (from PartialSolarIrradiation)Radiation per unit area
WeatherData.BusweaBus (from PartialSolarIrradiation)Bus with weather data
Modelica.Blocks.Interfaces.RealOutputHSkyDifTilHemispherical diffuse solar irradiation on a tilted surface from the sky
Modelica.Blocks.Interfaces.RealOutputHGroDifTilHemispherical diffuse solar irradiation on a tilted surface from the ground

Revisions

  • May 15, 2026, by Jianjun Hu:
    Changed the class type from block to model.
    This is for IBPSA, #2122.
  • September 6, 2021, by Ettore Zanetti:
    Removed parameter lat as it is now obtained from the weather data bus.
    This is for IBPSA, #1477.
  • November 14, 2015, by Michael Wetter:
    Added min, max and unit attributes for rho.
  • June 6, 2012, by Wangda Zuo:
    Added contributions from sky and ground that were separated in base class.
  • February 25, 2012, by Michael Wetter:
    Changed component to get zenith angle from weather bus.
  • May 24, 2010, by Wangda Zuo:
    First implementation.