Horizon Profile

A Horizon Profile is the graphical or analytical representation of all horizon obstructions surrounding a solar installation site. It shows the elevation angle of objects—such as trees, buildings, hills, and terrain—that may block sunlight during different hours of the day and seasons of the year.

In solar PV design, a Horizon Profile is essential for accurate shading analysis, irradiance modeling, energy forecasting, and system performance calculations. It helps designers understand how surrounding features impact solar access and guides decisions on array placement, tilt, orientation, and energy yield.

Modern solar tools such as Shadow Analysis and advanced design engines within Solar Designing use horizon data to model sun paths and compute performance metrics with high accuracy.

Key Takeaways

A Horizon Profile maps surrounding obstructions and their impact on sunlight throughout the year.
Essential for accurate shading analysis, POA calculations, and energy modeling.
Used in residential, commercial, and utility-scale PV design.
Helps optimize tilt, azimuth, module placement, and energy forecasts.
Plays a critical role in advanced solar design workflows in tools like SurgePV.

What Is a Horizon Profile?

A Horizon Profile is a 360° mapping of the horizon from a specific location. It captures the elevation angle (vertical height) of any object that may obstruct direct sunlight.

This profile is used to determine:

When the sun will be blocked
How long shading will occur
Seasonal impacts on solar energy production
Optimal panel placement to avoid obstructions
Loss factors included in system modeling (like in POA calculations)

The Horizon Profile is one of the foundational inputs in shading and energy modeling workflows, complementing related terms like Sun Path Diagram, POA Irradiance, and Shading Analysis.

How a Horizon Profile Works

1. Location data is captured

The designer specifies the site coordinates or imports them automatically using Lat/Long Auto-Detection.

2. Obstruction heights are detected

This can be done using:

Drone surveys
LiDAR data
3D modeling
On-site measurements
Satellite imagery

3. Software calculates elevation angles

Each obstruction’s angle above the horizon is computed using trigonometry.

4. A horizon curve is generated

The tool maps:

Azimuth (horizontal angle, 0°–360°)
Elevation angle (vertical height of the obstruction)

5. Shading losses are integrated into performance modeling

The Horizon Profile feeds directly into calculations for:

Annual shading percentage
Winter/summer shading impacts
Morning vs. evening obstruction
System performance ratio (PR) adjustments

This process ensures accurate energy modeling in tools like Solar Designing.

Types / Variants of Horizon Profiles

1. Flat Horizon Profile

Used in open-land or rural locations with minimal obstructions.

2. Urban Horizon Profile

Characterized by tall structures, uneven skyline, and heavy shading variation.

3. Terrain-Based Horizon Profile

Generated in hilly or mountainous regions where elevation changes dominate shading.

4. Vegetation-Based Horizon Profile

Accounts for trees and seasonal leaf density variations.

5. 3D Horizon Profile

Built from drone scans, LiDAR, or point clouds—high accuracy for engineering-grade modeling.

How Horizon Profiles Are Measured

1. Azimuth (°)

Direction around the full 360° circle.

2. Elevation Angle (°)

Height of the obstruction above the true horizon.

3. Shading Duration (Hours)

How long the sun is blocked at specific times of the year.

4. Diffuse Light Reduction (%)

Used in shading loss calculations.

5. POA Impact (%)

Effects on plane-of-array irradiance—see POA Irradiance.

Typical Values / Ranges

Values vary heavily based on latitude, terrain, and surrounding objects.

Practical Guidance for Solar Designers & Installers

1. Always generate a Horizon Profile before shading analysis

This ensures accurate modeling in tools like Shadow Analysis.

2. Use high-accuracy data sources

Drone scans or LiDAR provide exponentially better accuracy than satellite imagery.

3. Compare multiple array locations

A rooftop may have multiple planes with different horizon conditions.

4. Adjust tilt and azimuth based on horizon obstruction

A high eastern horizon means prioritize afternoon production.

5. Account for vegetation growth

Trees grow yearly—plan for future shading.

6. Use the profile to refine proposals

Integrate shading-adjusted forecasts using Solar Proposals to set clear customer expectations.

7. Validate on-site when possible

Laser tools or fisheye-lens capture (e.g., SunEye-style images) confirm data accuracy.

Real-World Examples

1. Suburban Roof Installation

A home has tall trees on the east side creating a 25° horizon blockage.

Designers shift modules to the west-facing roof plane to maintain annual yield.

2. Commercial Flat Roof

A neighboring building casts a winter morning shadow.

The Horizon Profile shows a 15° obstruction from 8 AM–10 AM, prompting higher tilt and row spacing adjustments.

3. Ground-Mount in Mountainous Terrain

A solar farm site is surrounded by rolling hills.

The Horizon Profile identifies a 40° obstruction in the west during winter months, influencing inverter clipping analysis and energy projections.