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:
- DC capacity Size
- PV module manufacturer and module count
- Tilt and Azimuth of the array
- 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:
- Monthly Sun Access and Shading Averages (ONLY when using the SAM calculator)
- Hour by Month Sun Access (ONLY when using the SAM calculator)
- Sun-path Diagram
- 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.
- Requires a 3D design.
Steps to generate Shade Report
- 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.
Go to Project > Info
Click Generate Document within the Project Files section and select Shade Report (Generic)
- 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.
- 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.
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.
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: