How to load horizon shading into the design

Summary

This article explains how to use OpenSolar’s horizon shading functionality to model shading effects from distant landscape features like mountains or ridgelines—obstructions too far away to be captured by 3D modeling tools. You’ll learn:

• What horizon shading is and when to use it

• How to upload and manage .hor files within your design

• The correct format for creating custom horizon shading files

By using this feature, you can improve the accuracy of performance estimates, especially in mountainous or hilly regions.

What is Horizon Shading?

Horizon shading represents shading caused by distant, elevated objects that lie on or near the horizon—such as:

• Mountains

• Tall hills

• Distant tree lines

Unlike near-shading, which is modeled using OpenSolar 3D or satellite data, horizon shading defines shading by angle at each azimuth direction, simulating how the sun might be blocked at low solar angles during sunrise or sunset.

OpenSolar uses this data to calculate how much solar irradiation is blocked at specific times of the day and year, improving the accuracy of system performance modeling.

How to Use Horizon Shading in OpenSolar

To apply horizon shading in your design, follow the steps below.

Enable OpenSolar 3D

• Open the Design page of your project.

• Click the Design Mode button in the top right.

• Switch to the 3D mode.

• Click Select to apply and activate the 3D environment.

Note: The Horizon Shading button will only appear when OpenSolar 3D is active.

Ensure a Compatible Map Layer is Active

You must have one of the following map views enabled:

• Google 3D

• Nearmap 3D

• None (for manual design)

Access Horizon Shading Settings

• Click on any panel group (horizon shading applies to all arrays in the project).

• Go to the Shading section in the left-hand settings menu.

• Click the Horizon Shading button to open the file upload manager.

Upload or Manage .hor Files

Once in the horizon shading interface:

• Click Upload New Horizon File to add your custom .hor file.

• Use the bin icon to delete an existing horizon file.

• After uploading, zoom out in Studio mode to visually inspect the horizon profile applied to your project.

• You can also return to the panel’s Shading section to review the shading impact from the horizon data.

How to Format a Horizon Shading File (.hor)

OpenSolar expects a .hor file to contain two columns:

1. Azimuth (degrees)

2. Horizon Angle (degrees)

Each row defines the elevation angle of the horizon at a specific azimuth direction.

Format Notes:

• Azimuth values can be defined in the range:

  • -180° to +179° (with 0° = South)

  • or 0° to 359° (with 0° = North), depending on your preference

• You do not need to define all 360 degrees—just enter the azimuth-angle pairs that represent significant obstructions

• Any azimuth direction not defined will be assumed to have a horizon angle of 0° (i.e., no shading)

• The file can be created or edited using any text editor and saved with a .hor extension

Best Practices

• Use horizon shading when designing in mountainous or hilly areas, where standard 3D models miss far obstructions.

• Validate your uploaded horizon profile visually in Studio mode.

• Keep your .hor files simple and clean—only define the azimuths that matter.

• Edit horizon files in plain text format for compatibility.