Shading analysis

Introduction

PVcase Roof Mount provides a simple and effective solution for conducting shading analysis, which is explained in this article. 

When developing a roof-mounted project, you need to evaluate the near shading impact of objects both on and surrounding the roof. Getting shading analysis right when planning solar panels helps you optimize their placement. This translates into enhanced energy output, superior efficiency, and a robust return on your investment.

To start, click on the Shading analysis button.

Once opened, we will see two different tabs:

• Irradiance data analysis. This analysis will take irradiance data obtained from the selected location and from PVcase Yield to provide you with shading loss percentage and irradiance data from every module in your layout.

• Shading projection. This analysis will provide you with the projection of the shadings on a desired date and time for the selected location.

In the sections below, you’ll find out more about both types of analysis on a project.

Irradiance data analysis

To perform an Irradiance data analysis, follow the steps below:

• Type the name of the project location OR
• Insert the coordinates

In the Shading analysis results window, you’ll be to toggle between two different analyses:

• Yearly shading loss: the percentage value of the yearly losses due to shading.
• Yearly in-plane irradiation: the values of the yearly irradiation received by each module.

Yearly shading loss

You can display the yearly shading loss values for every module as a percentage value, as a color gradient, or both simultaneously. This analysis is particularly useful to identify the most shaded modules and get an idea of the impact resulting from having them on the layout.

The Shading loss display settings provide some key insights into your layout and allow you to customize what you see.

Values and color gradient

You will see the two available display settings. Switch on/off the corresponding toggles to show or hide module values (kWh/m2) and color gradient.

Minimum and maximum shade loss percentage

For example, in this layout, you can easily see that the minimum shading loss percentage is 0.2% and the maximum is 0.6%.

Modules within a loss percentage range

You can filter out the modules affected by a specific loss percentage. There are two ways of doing this:

• Scroll the bar from the minimum or maximum to find the affected modules.
• Manually input the desired shading loss percentage value in the minimum or maximum fields.

In this example, we have set a minimum loss percentage of 8.3% and left the maximum value as is:

To see the modules within your desired range, click on the Apply filter button. The modules displayed after filtering are the affected ones.

You can delete the affected modules within your analysis by clicking the Delete modules in this range button. In this example, they represent a total capacity of 3.1kW. 

You can also repeat the analysis, by clicking Run new irradiance analysis.

Yearly In-Plane Irradiation

You can display the values of the yearly irradiation received by each module. The display of the results is very similar to the Yearly shading loss results. The main difference is that the units will be kWh/m2.

The In-plane irradiation display settings provide some key insights into your layout and allow you to customize what you see.

Values and color gradient

You will see the two available display settings. Switch the corresponding toggles on/off to show or hide module values (kWh/m2) and color gradient.

Modules within an in-plane irradiation range

You can filter out the modules within a specific in-plane irradiation range. There are two ways of doing this:

• Scroll the bar from the minimum or maximum to find the affected modules.
• Manually input the desired in-plane irradiation value in the minimum or maximum fields.

Use the Apply filter button to identify modules receiving less than 1724.4 kWh/m2 and apply the filter:
In this example, the capacity within that range is 3.8 kW.

If you want, you can click Delete modules in this range to remove those modules from the layout.

Shading projection 

You can use the Shading projection analysis to display the shades generated by objects on and around the roof at a specific location, date, and time of year.
To do so, follow the steps below:

1.  Click on the Shading Projection tab:

2. Set the location: Click on the globe icon and then

• Type the name of the project location OR
• Insert the coordinates

If the drawing includes location coordinates, they will automatically appear in this section.

3. Set the date and time for the projection of the shades.
In this example, since the project is in the northern hemisphere, we will choose solar noon on the winter solstice - December 21st, 13:12 hours (Local Time).

4. Click the On button to display the shading lines:

From these results, we can differentiate between two different scenarios:

• Modules with a fuchsia shading line: modules that are not shaded by other modules or shading objects

• Modules are hatched in fuchsia: the shadow generated by a nearby shading object shades the module.

Comparing results

To take the analysis a step further, you can overlay the yearly shading loss with the shading projection. You can see that for both analyses, modules affected by the shadings are the ones located near shading objects — object blocks on the roof.

Irradiance data analysis vs. Shading projection

Here is the main difference between the two:

• Irradiance data analysis calculates values for the entire year.
• Shading projection only captures values for a specific moment of the year.