Shading objects
With PVcase, you may add 3D shading objects that can be used to represent real-world objects that you may find in your PV plant area and its surroundings. Correctly defined and placed objects will allow you to perform shading analysis to see how they would affect the plant. This information can be used to enable more informed decisions about plant design with respect to these obstacles.
There are two options:
Predefined PVcase shading objects (customizable)
Custom shading objects
Predefined shading objects
The predefined shading objects can be found in the Tools submenu:
Here, the object type and its dimensions can be chosen. With "Add object" it can be added to the drawing.
Copy and paste can be used to multiply the objects. Once placed, the settings can be checked and changed by right-clicking on it and opening the PVcase - Edit Shading object menu:
The first object type available is a tree - you may choose the type of the tree from the drop-down menu below: it can be either Simple or Pine.
After choosing the tree type, you may define the height of the trunk and the diameter.
With trees, it may be necessary to place them in larger quantities, for example, to emulate a tree line adjacent to a plant. You may do so by drawing a polyline that would indicate the tree line you want to create. Then place a tree of your desired specifications at the beginning of the line and use the AutoCAD ARRAYPATH function to create copies of the tree along the polyline (or parallel to it, by defining an offset between line and tree). You will then be prompted to select the tree - having done so, press Space or Enter on the keyboard, and you will then be prompted to select the path you want it to follow. You may now observe the trees following the specified path and can modify the distance between trees by moving the blue arrowhead that shows on the second tree. To finalize, press Space or Enter on the keyboard.
The trees are now part of an array path, which, will not yet register as a shading object. To enable their use as shading objects, you should use the EXPLODE or BURST functions to sever that relationship. Having initiated the BURST command, select the trees and press Space or Enter on the keyboard.
Now, if you were to view the trees from a side view, they are all in the same elevation, regardless of topographical variance. To get them adapted to the terrain, select the tree object, right-click on it, and use Select similar to get all of the models selected. Once they are selected, use the MOVE command and move them by at least 0.001m. The objects will now be re-incorporated into the drawing, with the correct elevations present.
You should now have a group of trees generated along a designated path that can be used as shading objects.
You may also create Station objects - these are box-shaped 3D objects, for which we can define the X, Y & Z values.
These are commonly used to emulate buildings, transformer station blocks, and other entities that may be present in or around a given PV plant.
As you can see, having placed the trees and station block objects, they have a red outline. This is a companion polyline, which is in the PVcase offsets layer. This means that when the PV area is generated, PVcase will not place frames within these polylines. Offset restrictions may be freely modified to better represent real-world limitations and restrictions.
The fourth object type is a fence - you may define the height and width and offset of the fence blocks.
To place fences, draw a polyline that you want your fence to follow. When you click on Add object, you will be prompted to select a fence polyline. Select your polyline and press Space or Enter on the keyboard. Having done this, you may enter the isometric South-West view and see that you now have a 3D fence surrounding your PV area.
The fifth object type is Wind turbine - you may define the Tower height, Tower width, Blade length, and restriction if needed.
To place an object press on Add object and place it to a necessary location.
The last object is the Electricity pylon - you may define Pylon height, Pylon base width,
Width of arms, Structure thickness, Number of arms, and restriction if needed.
To place an object, click on Add object and place where necessary.
To save time and avoid the manual work of replacing already placed shading objects, we also have an option to edit already placed shading objects. To do so, select the shading objects you want to edit, right-click, navigate to PVcase, and click on the Edit shading object function. The object parameter window will appear, and you will be able to change the parameter of the shading object. After changing the parameters, click OK.
Tree Batch Creation
It's possible to add batch placement of trees as shading objects, based on the topographical data. This option is available on the Shading objects menu:
To deploy this functionality, you may follow these steps:
Select the topography in the Layout generation settings.
Click on the batch create option in the Shading objects menu.
Select the one object in the drawing that corresponds to a tree.
The software will then ask to select the tree height, which can be previously defined as text objects.
The trees will be generated on the PVcase Tree Layer taking into account the height, and the diameter of the CAD object.
It's worth mentioning that if PVcase can't find a text height for the tree inside the round object that represents the tree itself, it will not design that particular tree. And the following message will be shown:
We recommend using a configuration similar to the following to avoid such errors:
If everything is done right, the final result should be as the one shown below:
Custom Shading Objects
If you have an AutoCAD object of type 3D Solid or Mesh (not Polyfacemesh), you can use it as a shading object.
To do so, select the 3D Solid or Mesh, and right-click. Under the PVcase menu, choose "Convert to PVcase shading object".
Be aware that custom shading objects can be used in PVcase Ground Mount and Yield analysis; however they are not compatible with PVsyst.
Shading analysis
The Shading analysis function can be found in the action tool bar:
You will be able to specify the PV plants site location, the specific time or time interval for which you want to run the analysis and select the shading objects you want to work with.
Location selection
You have an option to enter the coordinates of your location in the Latitude and Longitude fields or alternatively, you are also able to click on the globe icon and open up the location selection menu.
You may mark your location on a map or search for the name of the location with the help of the search field. If you type the name of the location, the software will propose locations matching the name, narrowing the selection. Once you find the appropriate area, click on it and click OK to exit out of the menu.
The location should match the one that is set in the Frame & Parks settings, under Park settings.
Shading object selection
Select the objects you want to simulate the shading for, otherwise, they will not be represented in the analysis. To do so, click on Select Objects and select the objects you want to account for. With fixed-tilt systems, you can select all of the shading objects that were defined, as well as the PV frames themselves.
Once all objects are selected, press Space or Enter on the keyboard. You are now ready to specify the simulation time and perform the analysis.
Time & Sun position
Specific time shading analysis
In the shading analysis window, you may select the specific time or a range of time at which you want to perform the shading analysis.
Typically, in the Northern Hemisphere, noon on the Winter solstice is the most conventionally tested time, while noon on the Summer solstice is most common in the Southern Hemisphere.
If your site location coordinates and the time match, the sun position angle will also match.
This is important because the inter-frame shading simulation will only be accurate if the PV area generation and the shading analysis sun angles match. Deviating from this may lead to inaccurate results.
You may now perform the shading analysis by clicking Show Shading. You will be presented with different shapes indicating the shading. These will be elaborated upon in a subsequent section of this topic.
Time-range shading analysis
You are also able to specify a time range of your choice on a given day, at which the software will test the shading. The tests will be performed in 15-minute steps, meaning that if our range is 11:30 to 12:30, the software will perform the tests every quarter-hour, for a grand total of 5 times.
This has the implication that the software will need more time to compute the results - the broader the range and the more shading objects are simulated, the longer the results will take.
You may now perform the shading analysis by clicking Show shading and you will be presented with different shapes indicating the shading.
If you were to compare the results of the fixed-time analysis and of the time-range analysis, the shading differs from the specific time analysis - the shadows are much larger and some stepping can be noticed - this is due to the aforementioned 15-minute stepping interval. The markings will be elaborated upon in a subsequent section of this topic.
How to interpret the shading analysis results
Having generated a shading analysis, you may now leverage the newly presented information and implement it for future iterations.
You may start by observing the inter-frame shading. This is the shadow that is being cast from one frame to another. It results in a magenta outline showing the affected terrain. If the shadow that is being cast is covering the frame in front of it, the affected areas will have a magenta coloring on top.
If the simulation was performed at the same time and location that was specified in the Frame & Parks setting window, on flat terrain there should be no inter-frame shading present. If the simulation was done at another time or for an interval, the frames could partially shade each other.
With topography-enabled designs, there are situations where there still may be shading on frames, even if the previously specified conditions are met. For example, if you have a situation where a frame is casting shade downhill and the subsequent frame is placed at the maximum pitch distance, there may still be some shading on the lower portion of the frame that is downhill from the casting frame. To fix that you would need to increase the maximum pitch or inner spacing and regenerate the frames.