Probably one of the most important part of any tracker project design is the piling aspect. With this tutorial we'd like to bring in some clarity on how to use PVcase to set piling ranges, analyze problematic terrain areas.
Setting initial pole length
To start off we need to enter the data of our tracker table which we can simply reference from data provided by a manufacturer. Let's imagine that we have a section like this given as initial data.
It is important to note that at this point PVcase does not have an input for the torque tube fitting that is the 0.2m. shown in the drawing and this part of the framing adds up with the 1.8m. pole length value inside PVcase.
Setting up these parameters inside PVcase using this information will look something like this.
After this step we can customize the piling of the tracker by clicking on Custom piling. Once there we enter the amount of poles, distances between them and add overhangs if needed. For the sake of keeping this tutorial concise we'll not delve into that topic.
Setting pole reveal range
The next step would be to move to the Park settings tab and enable the checkbox for Terrain tolerance. Enabling terrain tolerance will allow us to set hill and ditch tolerances so that we can identify which tables might have terrain collision or might be too far away from the terrain along with setting the pole reveal ranges.
To start off, we can enter 0 values into the hill tolerance and ditch tolerance. On the right side view you'll see an indication of the pole length range which is now at 2-2 because the range inputs are at 0:
As you can see the pole length that we defined in frame creation (2.000m.) is used here as a reference length for the range. Now, depending on our pole reveal ranges we can alter this range by changing the inputs on the left.
- Allowed hill under frame - which will set the lower limit of the pole reveal range.
- Allowed ditch under frame - which will set the upper limit of the pole reveal range.
- Ditch radius from pole - this is the radius PVcase will check around the poles. If you're working with piling ranges you should set this by default to your pole radius.
For this example - we know from the tracker manufacturer that our piling reveal can range from 1.8m. to 2.3m. for standard trackers. (no differentation interior/exterior). Therefore, we'll add the following values in those inputs:
- Allowed hill under frame 0.200
- Allowed ditch under frame. 0.300
- For the ditch checking radius - we're leaving this at 0.2m. from the pole. (our pole radius is 0.2m.)
Generating tables and analyzing results
After these parameters are set we can start working with the drawing. When we generate the tables we should get a layout that has color coded tables based on the type of terrain problems they have. This is an initial indiacton of which tables have piling that are going out of the defined range (purple, orange)
Hill tolerance (orange) tables
The terrain collision gets checked throughout the entire table. Because of this the pole lengths might be in range but collision could still be happening.
Therefore - these tables will not only require grading but an additional look through whether the pole reveal is actually in range of what you set.
To check this we can generate the Piling information through the Layout information:
Generating the Piling information will number the piers and also provide the reveal length of the piling. Once that is done we can have a closer look at the orange tables to see whether some of them actually do have pole reveal ranges out of limits.
Ditch tolerance (purple) tables
Different from the hill tolerance checking - the ditch checking only happens at the pole position or in radius from it. That's why if you're only intersted in checking the pole locations you should set the checking radius in settings to be similiar to your pole radius.
In this case you can be sure that if there are any tables that are marked in purple they will have poles that are too long and out of your designated range.
As we have the tables placed we can then check how much capacity will we be losing if we don't do site grading. To do this you can select the areas using the Layout information window and filter out the problematic table types.
For this example we can see that we have 115 units of tables or 4.14 MW worth of capacity that is in need of grading and have piling going out of the range limits.
At this stage you can take this table layout with the color coded tables and use it as a basis for your cut and fill works.
Once the cut and fill is done we can place the new terrain underneath the tables and click on Adapt to terrain and select all of the tables to place them on the graded terrain. If all of the tables are within their piling reveal ranges that you set they will not indicate as problematic (yellow, orange, purple).
Exporting to EXCEL for further work
As the last step you can export all of the piling information along with coordinates and pole lengths to excel for a piling BOQ and group the poles based on their reveal lengths.
Don't forget that the pole length is for the entire pole along with the torque tube so based on your settings you might need to subtract it's size from the pole aerial length column.