Fixed-tilt - PV layout creation – Help Center | PVcase

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Fixed-tilt - PV layout creation

Prior to starting with frame creation, it is necessary to set up the Layout generation settings. This can be done by clicking on the Layout generation settings button and adjusting the information that is present there.

In the Layout and generation settings menu it is possible to proceed with the following selections:

Select the Restriction zone layer (boundaries on this layer will be devoid of frames).
Select Distance units (millimeters/meters or inches/feet).
Select Slope units (degrees, percentages).
The Optimized frames option hides unnecessary objects (3D modules, poles) to increase the performance of AutoCAD.
The Topographic layout option allows generating on a terrain survey, or on a flat surface when you do not have terrain data.
Using the Select button you can select or reselect the terrain data to be used.
Change from Existing (original) topography to Proposed topography (after performing the grading).

The next necessary step before area generation is to set up the Frame & park settings. This can be done by clicking on the Frame & park settings button and adjusting the information that is present in the three tabs there. This includes the physical parameters of your frames, placement & park layout settings.

Frame creation

Using the Current preset field and adjacent icons you can:

Use custom names for frame presets;

Duplicate the current frame preset;

Copy a selected frame’s information;

Delete an existing preset;

The Module Parameters section allows you to define custom module parameters to match those that are provided by your module manufacturer of choice.

The Frame parameters section allows us to specify:

The framing type (fixed-tilt, single-axis tracker, or east-west). In our example, we will use fixed-tilt.

The module orientation - either portrait or landscape. In our case, it will be a portrait.

The grid size of the frame - we can specify the number of rows and columns.

The Tilt angle.

You may also choose to modify the horizontal and vertical gaps between modules.

The frame power is determined by the power of the individual modules, multiplied by the number of modules per frame.

We then go to the Custom Piling menu to adjust the piling information for this specific frame.

We may specify if the piling distribution should be custom or even.

With Even distribution, the software makes it so that the inter-pole gaps are of equal size. We can also choose if we want the margins to be independently editable, or for them to be equal. And just under the margin field, we can see the calculated middle distribution value. All of this is displayed and updated on the illustration on the right-hand side of the window.

In our case, we will use the custom pole distribution and set the horizontal pole amount as 6. As you can see, we are freely able to adjust the spacing between the poles. The selected spacing is displayed and updated on the illustration on the right-hand side of the window.

If the edges of the frames don't coincide with the edge of the first/last module, we can add an overhang:

Then we configure the vertical poles. We select the vertical pole amount to be 2, and we can freely adjust the gap between the pile and the module and the spacing between the poles. All changes can be observed in the figure on the right side of the window.

Once we are done with the piling, we click OK to exit out of the menu window.

If you would like to use the same preset in another project, just use the export/import presets button:

For more information about importing and exporting settings, proceed to the article below:

Import and export settings

Placement Setup

Having explored the Frame Creation capabilities of PVcase, we can now explore the placement setup options. Firstly, we open the Placement Setup menu tab and select Fixed-Tilt Frames.

Here we see the Preset Library field which contains all the presets we created just before for this specific DWG file. From here you can select which of the available presets we should use when creating new PV areas. You can select one or multiple presets that you would like to utilize, as long as they have matching row counts, vertical gap size, and tilt angles.

As with our example, we can see that we are not able to select one of the presets as it has 2 rows rather than 3.

There is also an option to choose a specific color for each preset, to do so just click on a color box choose the specific color and press okay to finalize.

Just below the Preset Library field, we can see the option to select the frame placement order:

Descending from the alignment side denotes that when populating the PV area, the software will put larger frames closest to the alignment line and will keep the smaller frames on the opposite side.

Ascending from the alignment side would place the smallest frames closest to the alignment line, placing the largest frames furthest away from the alignment line.

Park settings

Having created and selected our frame presets, we will now proceed to the Park settings options.

We can see that the three main sections are Project settings and Design settings:

We are presented with two options to establish our Shade limit: either by defining a specific Sun position angle or by utilizing the Time at the location of the site.

Assuming we use the time-based shade limit option, we would click on the globe icon, which allows us to either move around the embedded map, placing a pinpoint for the location, or by searching for the general location with the text field search. We will use Vilnius for this example and click Ok once we are done.

This enables us to set the time and date for which we would like to perform our calculations. As would be typically used in the northern hemisphere, we will set our date as December 21 in our example and then we can adjust the time at which we would like to get the results. This can be a specific time, dawn, mid-day, or twilight and the software will adjust the Sun’s altitude accordingly.

When the solar panels are placed, they should be arranged with a particular pitch such that it mitigates shading for this time and date.

If it is more applicable, you may also choose to use the Shading limit with Angle rather than Time as the variable. PVcase would allow you to manually edit the sun position field rather than use the values given from the date/time calculations.

Here you also have the option to indicate if you want to allow a certain percentage of shading. In the example below, 33.33% shading was allowed, therefore, at the set time/angle the shadow of the table in front doesn't not hit the second module (max. 1 out of 3 modules is shaded):

Learn more about Shading analysis in Shading objects & shading analysis.

In the Design settings section, we can define the spacing between rows of frames in various conditions.

The minimum inner spacing & pitch are used when the next row of frames is going uphill (positive altitude delta, South slope in the Northern hemisphere).

The flat inner spacing & pitch are used when the next row of frames is in the same elevation (no altitude delta);

The maximum inner spacing & pitch are used when the next row of frames is going downhill (negative altitude delta, North slope on Southern hemisphere).

Ideally, when operating within these tolerances, we should be able to get a park layout with no inter-frame shading. Should there be a scenario where you want to have a fixed distance between the frame rows, this can be enabled by checking the Fixed distance field. Please note that this is only available when you use the Angle Shade limit.

You also have the option to toggle the Aligned frames parameter. it can be used to generate frames in a more orderly fashion, especially in less space-constrained areas. As a consequence, it is not as efficient with the power capacity of the park, and disabling this option would allow us to better utilize the park area.

Another possibility is to have Corridors for fixed-tilt systems.

In the Corridor menu, you can define spaces for access or maintenance roads, therefore, dividing our fixed-tilt layout into separate clusters. It is also possible to define a second vertical gap when using corridor-enabled designs.

This allows for the creation of patterns to better position central inverters and roads.

To enable the use of corridors in fixed-tilt design, click on Corridors and we are presented with the corridor settings window. Here we have the option to enable corridors in our design by toggling the checkbox. This allows us to adjust the corridor grid size, the gap sizes (both primary and secondary (if the latter is checked) and to toggle on and off corridor lines. The corridor lines can be later converted to roads using PVcase.

Once we are satisfied with the corridor design, we click on Confirm to finalize our settings.

Should your application require it, it is possible to modify the azimuth of your frames by up to 89.9°. To set the azimuth, either you enter a value or you draw it by clicking on the Draw button:

You may also toggle the frame orientation by choosing North or South in the drop-down menu. This is dependent on the location of your solar park. Generally, in the Northern hemisphere, we would use south-facing frames, while in the Southern hemisphere, we would use north-facing frames instead.

Height & Optimization

The Height settings section allows us to define the frame height for the PV area we intend to generate. Please note that the input field is for the reference height rather than the minimum clearance height. PVcase places frame corners based on the reference height, without taking terrain collision in other places of the frame into account. However, terrain collision can be analyzed at a later stage, as part of our Civil analysis section.

The illustrations below help us visualize how the reference height is applied in the Standard mode, and how it affects the highest point of the frame and the pole lengths.

With the Optimized mode, instead of a fixed reference height we can set a reference range.The algorithm will fine-tune the placement of each frame so that grading collisions are minimized while keeping each frame corner within the clearance range. By doing so, the resulting layout minimizes potential grading volumes and pile lengths.
But once again, no minimum clearance is guaranteed.

Area generation

The first step in generating areas is to define the PV area in which we will be working. A PV area in PVcase should be defined by a closed polyline. This can be done by using the default AutoCAD polyline function. This can be summoned by typing PLINE and pressing ENTER and drawing the desired perimeter of the PV area, ensuring that the polyline is finished at the starting point. This will yield a closed polyline, suitable for PV area population.

Once the Frame & Park Settings are configured to your specifications and we have a suitable PV area perimeter polyline, we can generate the PV areas in one of two ways either one at a time or multiple PV areas simultaneously.

First, let us showcase the creation of singular PV areas. While the single area option is the default, you can select whether you want to generate a single area or multiple areas by clicking on the drop-down menu and choosing Generate single area. Having chosen this option, we are prompted to select our PV area boundary - select our newly-drawn polyline and press Enter on the keyboard. You will then be prompted to define an Alignment line. An alignment line is used to indicate the alignment bias of PV frames when creating PV areas. We can draw alignment lines on the PV area perimeter polyline as well as inside of it and outside of it. In our example, we will draw the Alignment line in the middle of our PV area - once we have our line, we press Enter or Space on our keyboards - this will initiate the generation of our frames in the PV area. Depending on the size of the area, this should only take a few seconds - we can now see our newly-generated frames in the PV area we defined.

For our next example, let us clear the PV area by right-clicking on the PV area perimeter line, going to the PVcase sub-menu and clicking on the Clear PV area option.

Then we create an extra PV area. Let us use the same PLINE command to draw another PV area.

We now have two viable PV area perimeters, which enables us to illustrate how one can generate multiple PV areas simultaneously. By clicking on the dropdown menu, we select the Generate multiple areas option, which prompts us to select our PV areas. Once both areas are selected, press Enter on the keyboard and draw the alignment line for both areas - when generating multiple areas simultaneously, you are restricted to having a singular alignment line for both. Once you have the alignment line, press Enter or Space and we will have both PV areas populated shortly.

A third way of generating the layout would be using the Capacity iteration which allows to calculate different scenarios based on varying row spacing and tilt angle.

Learn more in Capacity iteration.

Row alignment

PVcase has the option to enforce row alignment, meaning that PVcase will make an effort to keep the same layout as much as possible. The software will opt to keep the uniformity of the layout, choosing not to populate areas with objects in the PVcase Offsets layer (for example, trees/buildings) or if the PV area is non-rectangular, it may opt to not populate certain regions of the area.

Meanwhile, unaligned rows will make a greater effort to more densely populate the entire PV area at the cost of uniformity, while respecting the PVcase Offsets layer restrictions.

For our first example, we will draw a restriction zone in our PV area with the REC command and assign it to the PVcase Offsets layer. We will then generate a single area as shown previously, with aligned rows disabled. As we can see, the software places the rows closer to the restricted areas, but with less regard to the grid alignment.

If we were to replicate the same steps, only with Aligned Rows enabled, we can see that the layout is more uniform but it is less than optimal, capacity-wise. Further manual adjustments may be necessary to achieve higher capacity.

Piling generation

Once the PV areas are generated, we can proceed to generate our piling. This can be done by clicking the Generate Piling button, selecting the PV area perimeter line, and pressing Space or Enter on the keyboard.

Soon enough, your frames will be populated with their poles. To see what the piling looks like, we may choose an isometric view (SW Isometric, for example) and/or while holding the Shift key and Middle Mouse button to rotate the view manually using the mouse.

Pile Grouping by length

This function allows us to see how many piles belong to each length group and how they're spatially distributed, allowing to spot problematic areas in need of changes to either pole lengths or grading.

Run Show piling as described above
Open the Pile grouping window from the same drop-down menu:
Define the start and end values of the length groups and the increments between each and customize group colors:
Select PVarea(s) and run Group piles - this will color each pile according to its length group and populate the pile count in the table:

Export to CAD model space and/or to the BOM Excel sheet

The following GIF shows the whole process:

Moving frames manually (shadow frames)

After generation, we can freely move tables around and copy them. However, sometimes they may turn red because they need to be adapted to the terrain or reassigned to an area. Until they are resolved they will not be counted inside the Layout information.

Learn more about how to work with shadow frames in Shadow frames.

Frame grouping with power station placement

Frame grouping allows you to quickly and easily group PV frames and place a power station to serve them. You can quickly "block out" a PV area for the initial phase of the design. There's no need to add any electrical devices (strings, combiners, inverters) at this stage. It's just to get an idea of where to place the power stations. This is useful at the preliminary design stage, where there is no time to do a full electrical design, but you need to give an idea of the power station locations for project stakeholders or authorities.

On the ribbon, select "Frame grouping" and a window will open. First, you can decide whether your Frame groups will contain power stations or not.

If enabled, you can set up the details of the power station. It can be modelled in two ways:

You can select an existing AutoCAD block object.
Alternatively, you can define the dimensions of the unit, and a block will be created for you.

The AC Power is used to determine DC/AC ratio when selecting the PV frames that will be assigned to the power station. The offset setting will displace any frames with the defined offset area. You can also choose the coloors that your frame groups will be created with.

When you want to start grouping the frames, hit "Create group."

First, select your PV frames, until you are happy with the DC/AC ratio and press Enter.

Then, if enabled, you can choose the position of your power station. Wherever you place it, PV frames will be automatically removed from the offset area that you have chosen.

If you chose not to place power stations, you will be prompted to pick frames for the next area. You can keep adding frame groups and power stations until you are done. The colors for the areas will be chosen according to your settings.

The grouping will also be displayed in the Electrical devices overview if you have enabled powerstation placement: