# Luminous Efficacy

![](https://3405893330-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9gBkJelXEQ5LsYEl7%2Fuploads%2Fgit-blob-caa5cf1053be79e2ac673201b9459021523f7cf5%2FLuminous_Efficacy.png?alt=media)

![](https://3405893330-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9gBkJelXEQ5LsYEl7%2Fuploads%2Fgit-blob-74b123481e72e6097af36f8735903b48a53eb9b6%2FLuminous_Efficacy.png?alt=media) - [\[source code\]](https://github.com/ladybug-tools/dragonfly-grasshopper/blob/master/dragonfly_grasshopper/src/DF%20Luminous%20Efficacy.py)

Esimtate sky illuminance from the irradiance contained within a WEA object.

## Inputs

* **wea \[Required]**

  A Ladybug WEA object. 
* **dew\_point \[Required]**

  An annual data collection representing dew point temperature \[C]. 

## Outputs

* **dir\_ill**

  A data collection of direct normal illuminance values at each timestep of the WEA. 
* **diff\_ill**

  A list of diffuse sky solar illuminance values at each timestep of the WEA. 
* **glob\_ill**

  A list of global horizontal illuminance values at each timestep of the WEA.