Fixed-tilt - Capacity iteration

Required, Capacity, Max, kW, kWp, Iteration, Row, Shading, Angle, Spacing, Pitch, Step, Fixed-tilt

Vito Bindokas avatar
Written by Vito Bindokas
Updated over a week ago

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Capacity iteration parameters

The capacity iteration tool can be used to run calculations to determine if it is possible to fit a certain power capacity within the given area (or multiple areas). It may also be used to populate PV areas with frames as you would using Generate Single Area & Generate Multiple Areas.

Prior to attempting to use the Capacity iteration feature, we must ensure that both the Layout settings and Frame & Park settings are established. These parameters will be used when performing capacity iterations.

We start by opening the Capacity iteration tool by clicking on its icon.

We are now able to select one or more PV areas (based on preference and/or viability) that you would like the tool to iterate. The Capacity iteration tool will remember your selection and will not require you to re-select should you need to reiterate the areas later. We will now select our PV area by clicking on Single Area in the Area selection field, then selecting the target PV area boundary line. Then we are prompted to draw an alignment line - once we have drawn it, we press Enter or Space on the keyboard to finalize the selection.

In the Iteration Parameters section, if we open the drop-down menu for the Iterate by field, we can see that we are able to iterate by pitch, inner spacing, or by the shading limit angle.

This determines which variable will be modified when the software attempts to find a configuration capable of achieving the target capacity value. This is entirely up to the user’s preference. For example purposes, we will iterate by the shading limit angle.

When iterating with respect to the Shading Angle, you can define your target Shading angle range, which will automatically recalculate and update the Flat pitch & Flat inner spacing values.

Also, important to know when setting up the Iteration parameters:

  • Start - for pitch and inner spacing the start value represents the maximum distance that the program will consider for the iteration. However for the shading limit angle, it works in the opposite way, the start value is indeed the minimum shading angle.

  • Stop - again, for the pitch and inner spacing this value corresponds to the minimum distance considered, and for the shading limit angle it will be the highest allowed angle.

  • Aligned rows - this is the same option presented in Frame and park settings. Using aligned rows will allow you to have a more orderly layout when there is enough free space.

You may also adjust the Distance limits field. These specifications are to be used when doing the iteration by the shading limit angle. They act as the maximum and minimum distances for placing tables considering the sun's position. Meaning that we are still able to get a variable distance between the specified shading limit angles, however, we can also set those limits as allowed distance variance.

Note: Having those limits in place may also imply having shading in certain areas because we are restraining the required distance to be shade-free for a given angle.

Capacity iteration example

We will start by opening our Frame & Park settings menu and copying our existing parameters. As you can see, we had our sun position value set as 15°. For the iterations, we will set our start value as 15° and the end value, for example purposes, as 20°. As we just saw, changing the shading angle values caused our Flat pitch and Flat inner spacing values to update automatically to match the Shading limit angle.

Then we must specify the iteration stepping value - this will determine how much granularity we want in our iterations. Lowering this value gives us finer control over the results, but at the cost of computational time. For this example, we will set our Shading limit angle stepping value as 0.5° and the target capacity we are looking to achieve as 10 megawatts.

Once we have all of our values, we click Iterate and the software will begin testing scenarios by altering the shading limit angle by 0.5° each time until it either reaches our target value or finishes attempting all available steps.

If there was a successful iteration you will get a pop-up window stating that it was successful, and it will specify with what pitch, minimum row spacing, and shading limit angle it was able to achieve the target power capacity.

You may check the area capacity that was achieved by going to the Layout information tab, pressing Select PV areas, selecting the generated areas, and pressing the Space or Enter key on the keyboard. As we can see, we were able to get slightly more capacity than we specified.

Should you want a more accurate iteration, you may repeat the iteration process with a lower limit angle step - for this example, we will reduce it by 0.4° and set it to 0.1°. Once we run the iterations again, we can check the Layout information tab and see that we achieved a more accurate result; This can be repeated until the desired result is achieved.

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