Annual Irradiance

Run an annual irradiance study for a Honeybee model to compute hourly solar irradiance for each sensor in a model's sensor grids.

The fundamental calculation of this recipe is the same as that of "HB Annual Daylight" in that an enhaced 2-phase method is used to accurately account for direct sun at each simulation step. However, this recipe computes broadband solar irradiance in W/m2 instead of visible illuminance in lux.

Consequently, the average irradiance and cumulative radiation values produced from this recipe are more accurate than those produced by the "HB Cumulative Radiation" recipe. Furthermore, because the hourly irriadiance values are accurate, this recipe can be used to evaluate peak_irradiance and determine the worst-case solar loads over clear sky Weas that represent cooling design days.


  • model [Required]

A Honeybee Model for which Annual Irradiance will be simulated. Note that this model must have grids assigned to it.

  • wea [Required]

A Wea object produced from the Wea components that are under the Light Sources tab. This can also be the path to a .wea or a .epw file.

  • timestep

An integer for the timestep of the inpput _wea. This value is used to compute average irradiance and cumulative radiation. (Default: 1)

  • visible

Boolean to indicate the type of irradiance output, which can be solar (False) or visible (True). Note that the output values will still be irradiance (W/m2) when "visible" is selected but these irradiance values will be just for the visible portion of the electromagnetic spectrum. The visible irradiance values can be converted into illuminance by multiplying them by the Radiance luminous efficacy factor of 179. (Default: False).

  • north

A number between -360 and 360 for the counterclockwise difference between the North and the positive Y-axis in degrees. This can also be Vector for the direction to North. (Default: 0).

  • grid_filter

Text for a grid identifer or a pattern to filter the sensor grids of the model that are simulated. For instance, first_floor_* will simulate only the sensor grids that have an identifier that starts with first_floor_. By default, all grids in the model will be simulated.

  • radiance_par

Text for the radiance parameters to be used for ray tracing. (Default: -ab 2 -ad 5000 -lw 2e-05).

  • run_settings

Settings from the "HB Recipe Settings" component that specify how the recipe should be run. This can also be a text string of recipe settings.

  • run [Required]

Set to True to run the recipe and get results. This input can also be the integer "2" to run the recipe silently.


  • report

Reports, errors, warnings, etc.

  • results

Raw result files (.ill) that contain matrices of irradiance in W/m2 for each time step of the wea.

  • res_direct

Raw result files (.ill) that contain irradiance matrices for just the direct sun at each hour of the simulation. These can be postprocessed using various components under the 4::Results sub-tab.

  • avg_irr

The average irradiance in W/m2 for each sensor over the Wea time period.

  • peak_irr

The highest irradiance value in W/m2 during the Wea time period. This is suitable for assessing the worst-case solar load of clear skies on cooling design days. It can also be used to determine the highest radiant temperatures that occupants might experience in over the time period of the Wea.

  • radiation

The cumulative radiation in kWh/m2 over the Wea time period.

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