What is a Shade Report?

OpenSolar's shade report allows you to easily and quickly generate a detailed analysis of the shade impacts on each module group (i.e. an array) of your system design on OpenSolar's when designing in 3D. The report provides a high-level summary of each module group and includes:

1. DC capacity Size
2. PV module manufacturer and module count
3. Tilt and Azimuth of the array
4. Sun Access, TOF and TSRF metrics (ONLY when using the SAM calculator).

It also includes up to 3 additional charts and graphs that break down the shading impact on the module group:

1. Monthly Sun Access and Shading Averages (ONLY when using the SAM calculator)
2. Hour by Month Sun Access (ONLY when using the SAM calculator)
3. Sun-path Diagram

Requirements:

1. Using either the SAM or MCS performance calculator. 
   • This can be set within the Design Page under Summary > Advanced Settings > Energy Production Calculator,
   • Or you can set a particular calculator as the default by going to Control > Design & Hardware > Setbacks & Design Settings > Simulation Settings > Energy Production Calculator.
2. Requires a 3D design.
   • If there is 3D data available at your project location, then you can directly use that. (More on this in this article)
   • If there is NO 3D data available at your project location, then you will need to create a 3D design of the scene yourself. (More on this in this article).

Steps to generate Shade Report

1. Ensure the system you want to generate a shade report is designed in 3D and has raytracing enabled. Otherwise you will NOT be able to generate the shade report.

2. Go to Project > Info

3. Click Generate Document within the Project Files section and select Shade Report (Generic)

4. If you have multiple System Options for that project, you will need to select the system option you want to generate the shade report on.
5. Click on "Generate" to create the report.

Note: Shade Report cannot be generated when facets are included with more than one type of imagery. Each oblique view counts as a separate imagery, and 3D is treated as a top-down imagery.

Terminology

Sun Access:

Sun Access describes the percentage of plane-of-array (POA) insolation incident on a PV module/array surface that is remaining after accounting for shading. Mathematically it can be described by the following equation:

It should be noted that OpenSolar takes into account of all 3 components of irradiance: direct, diffuse and reflected irradiance. Hence, the sun access value may be non-zero even if an object completely blocks out direct irradiance from reaching the PV modules due to contributions from diffuse and reflected irradiance.

Tilt Orientation Factor (TOF):

Tilt Orientation Factor (TOF) is the percentage of unshaded solar insolation at the actual tilt and azimuth of a module/array surface compared to the optimal tilt and azimuth; where the optimal tilt and azimuth is orientation that gives the highest annual generation. Mathematically it can be described by the following equation:

As a rule of thumb the optimal orientation that maximize insolation falling on a PV module is roughly when the tilt is equal to the latitude and facing towards the equator (i.e. azimuth = 0° for southern hemisphere and azimuth = 180° for northern hemisphere). However, in reality the optimal tilt is generally a few degrees less than the latitude.

Total Solar Resource Fraction (TSRF):

Total Solar Resource Fraction (TSRF) provides the ratio of insolation available with shading on a module/array surface, compared to the insolation at optimal module orientation with no shading. Mathematically it can be described by the following equation:

Note that you can also derive TSRF by multiplying Sun Access with TOF.

Sun-path Diagram

A sun-path diagram is a chart that illustrates the sun's location in the sky at any point of time during the day, and throughout the year at a single reference point. The sun-path diagram allows the sun's azimuth and tilt to be read off the chart, which allows the position of the sun can be determined. By mapping on a shade mask onto the sun-path diagram we can then determine when there will be shading experience by the PV system through throughout the year.

For UK users, the sun-path diagram will generate as per the MCS requirement (refer to the 2nd example below)

Example of the Shade Report for a Single Array

Example of the Shade Report (MCS) for a single Array: 

Note: All the information found in the shade report is completely free to use.