Understanding Your Solar Shading Analysis Report

After the initial excitement of deciding to go solar, you’ll receive a proposal from your chosen installer. Buried within the financial projections and equipment lists is arguably the most critical technical document of the entire process: the Solar Shading Analysis Report. To the untrained eye, it can look like an intimidating collection of charts, percentages, and strange diagrams. But in reality, this report is the foundation of your entire solar investment.

It is the definitive proof that your installer has done their due diligence, moving beyond guesswork to scientifically quantify your property’s true solar potential. In a country like the Philippines, with our lush landscapes and dense urban environments, understanding this report is non-negotiable. It is the key that unlocks a realistic understanding of your system's future performance and ensures the savings you are promised are the savings you will actually receive.

This guide will demystify the Solar Shading Analysis Report, breaking down its components into simple terms and empowering you to read it with the confidence of an informed consumer.

What is a Shading Analysis and Why Is It So Important?

A solar shading analysis is a detailed study of how and when shadows from surrounding objects will fall across your roof throughout the entire year. It’s a crucial part of a comprehensive solar assessment because of the profound impact of solar shade on system performance.

In a standard solar setup, panels are connected in series, like a string of Christmas lights. If a shadow falls on even one part of one panel, it doesn't just reduce that panel's output; it can act as a bottleneck, dragging down the performance of every other panel in the string. This domino effect is why installers can't simply ignore shade.

In the Philippines, the sources of shade are everywhere:

• The beloved mango tree in the backyard.
• The firewall of a neighboring townhouse.
• The ever-present water tank (tangke) on your own roof.
• A new high-rise condominium going up down the street.

A professional analysis doesn't just acknowledge these obstacles; it measures them precisely to calculate their exact impact on your energy harvest.

Decoding the Report: The Key Components

While the format can vary between installers, a professional report will contain several key elements. Here’s what to look for and what it means.

The 3D Model and Sun Path Diagram
The report is built upon a 3D digital model of your property. Installers use advanced software to create a "digital twin" of your home, including the exact dimensions and orientation of your roof, as well as the height and location of every nearby tree, building, and obstruction.

You will often see a sun path diagram, which looks like a web of arching lines over a circle. This diagram is a map of the sun's path across the sky from your specific location for every month of the year. It shows the high arc of the sun during the hot summer months and the lower, shorter arc during the cooler months. By overlaying the 3D model of the obstructions onto this sun path, the software can instantly visualize when and where shadows will fall. This entire process is a core part of how a professional solar shading analysis is conducted.

Solar Access Percentage (or TSRF)
This is one of the most important headline numbers in your report. "Solar Access" is the percentage of total available sunlight that your proposed solar array will actually receive after accounting for all energy lost to shade. You might also see it called the Total Solar Resource Fraction (TSRF).

A Solar Access score of 100% would mean a perfectly unshaded roof—a rare ideal. A score of 93% means that, over the course of the year, 7% of the potential solar energy is lost due to shadows. This single percentage gives you a quick, at-a-glance measure of your roof's quality for solar production.

Monthly and Hourly Breakdown
A detailed report will break down the Solar Access percentage by month. This is particularly useful in the Philippines. You might see that your access is very high from March to May when the sun is directly overhead, but dips in December and January when the sun is lower in the southern sky and long shadows are cast by trees or buildings.

Some advanced reports even provide an hourly heat map. This grid shows the solar access for every hour of every month. You can see, for example, that a tree on the east side of your property causes shading at 9 a.m. but is a non-issue by noon. This granular data is what engineers use to fine-tune the panel layout.

Derated Production Estimate (kWh)
This is the ultimate output of the analysis. A credible solar proposal will never show you an energy production estimate based on a perfect, unshaded scenario. Instead, it will provide a "derated" figure—an honest, realistic estimate of the kilowatt-hours (kWh) your system will generate annually, with the losses from shading already factored in. This derated number is the one that all financial calculations, such as your expected savings and return on investment (ROI), should be based on.

Interpreting the Results: What Your Score Means for Your System

Understanding the data is one thing; knowing what it means for your project is the next crucial step. Generally, you can think of the results in three tiers.

Green Light: Solar Access > 95%
A score in this range indicates that your roof is excellent for solar. Shading is minimal and will have a negligible impact on your system's performance. In this scenario, a standard, cost-effective string inverter system is likely the perfect fit. Your main focus will be on maximizing the panel layout for aesthetic and production purposes.

Yellow Light: Solar Access 85% - 95%
This is the range where the shading analysis truly proves its worth. A score here means that shade is a significant factor that must be actively managed. A professional installer will use this data to make critical design decisions. They might:

• Adjust the panel layout to concentrate panels in the sunniest zones, avoiding areas with the most shade.
• Recommend specific solutions for shaded roofs, such as installing DC Power Optimizers or Microinverters. These technologies allow each panel to perform independently, ensuring a partially shaded panel doesn't hurt the performance of the others.
• Discuss the possibility of trying to minimize shade through responsible tree trimming, if the obstruction is on your property.

Red Light: Solar Access < 85%
A score below 85% signals a serious shading problem. While it may not be a complete deal-breaker, it requires careful consideration. In this case, your installer should:

• Strongly recommend, or even require, the use of performance-enhancing technology like microinverters to make the project viable.
• Have a frank discussion about the project's financial return. A heavily shaded roof will produce less energy, extending the payback period.
• Potentially suggest a smaller system that is exclusively located on the single sunniest spot on the roof. In very extreme cases, they may honestly advise that rooftop solar is not the best investment for your property.

Conclusion: Your Blueprint for a Smart Investment

Your Solar Shading Analysis Report is more than just a technical formality; it's your personalized blueprint for a successful solar investment. It provides a transparent, data-driven look at the real-world conditions on your roof, allowing for a system design that is optimized for performance and reliability.

Take the time to go through this report with your installer. Ask them to explain the findings and how those findings have influenced their design choices and technology recommendations. A company that provides a detailed, easy-to-understand report and is happy to discuss it with you is a company that values transparency and engineering excellence—the two most important qualities in a solar partner.