Horizon Shading Overview
When a solar array has an elevated horizon, for example from a nearby mountain range, it will reduce the sunlight reaching the array and it can be modeled as a Horizon profile.
Horizon Data Sources
Horizon profiles can be generated using tools such as Solmetric SunEye or Solar Pathfinder. Other data sources include SolarAnywhere, which offers horizon data downloads. Any Horizon (.HOR format) or CSV file that lists the azimuth and elevation angle can be used to model a Horizon profile. In a Horizon file, the Horizon profile is interpolated linearly across each of the points (see the figure below).
Horizon Line along Azimuth Values
Horizon profiles are an excellent source of information for verifying real-life conditions surrounding the array. They are ideal for modeling far shading originating from features such as mountain ranges that are sufficiently far from the array. However, Horizon profiles are less precise than Keepouts for close or near shading, for example from objects such as trees and buildings located close by to the array.
In HelioScope, the shading caused by the horizon will be applied to the entire array: during the hours when the sun is below the horizon line (based on the solar angles and the Horizon file), the entire array will receive zero direct irradiance and produce energy only based on the diffuse irradiance.
Learn more about HelioScope's Shade Modeling.
Horizon File Upload Step-by-Step
1. Upload Horizon file to the Project
It is very easy to upload a Horizon file in csv or .HOR format, please see the example files and read more about the Horizon File Format to make sure you are uploading an accepted format as you may need to delete some fields from the file before using the uploader.
The Horizon files are Project specific and should be uploaded from the Project page on the Shading tab. Select the files you wish to upload, you may add several files to use in different Condition Sets if you have horizon profiles from different sources.
The horizon file data can be verified by clicking on the name of the file once it has been uploaded to view the horizon profile.
2. Select the Horizon file in the Condition Set
Once the Horizon file is available in the Project, it can be added to an existing Condition Set by editing the Condition Set (click on the edit icon) or to a new Condition Set by creating "New Conditions".
In the Horizon tab of the Condition Set select the Horizon file to be used.
3. Simulate the report with the new Condition Set that includes the Horizon file.
The report should include the Horizon file in the Condition Set section.