You may wish to add areas (such as roads or geographical features such as ponds or marshland) where you don't want racks or trackers to be placed. A simple way to do this is to add exclusion regions.
Adding new exclusion regions
Select the 'Exclusion Region' map tool (highlighted in red below):
Draw out a polygon defining the exclusion region and when racks/trackers are being added they are prohibited from being placed in exclusion regions.
The exclusion regions appear in the table in the Exclusion Regions tab in the 'Design layout' task page:
Exclusion regions have their own map layer, so you can change the visibility/opacity of them separately to the layout regions:
Importing exclusion regions from Shapefiles
See Importing Layout Regions (and Exclusion Regions) from Shapefiles for more details on how to do this.
Importing exclusion regions from Google Earth files
You can import layout and exclusion regions from polygons in Google Earth
You cannot currently define and save exclusion regions from the Google Earth application directly. You have to edit the .kml file (or unzip the .kmz and edit the doc.kml file enclosed within) and modify it. See Importing Layout Regions (and Exclusion Regions) from Google Earth files for more details.
Editing the shape of exclusion regions
You can edit the shape of a previously added exclusion region by using the Edit Boundary map tool (highlighted in red below):
Once selected, click on an exclusion region to put it in edit mode. You can move (click and drag) existing points, delete (using the Delete or Backspace keyboard key) existing points, or insert additional points (click on a boundary line) to the polygon boundaries.
Calculating exclusion regions from slopes
SolarFarmer can automatically calculate exclusion regions from the slope information of the terrain you have loaded into your workbook. You specify a type of slope (all directions, North-South only, West-East only) and a slope threshold, and it can calculate regions for all the areas that are at or above the slope threshold.
These exclusion regions will prevent racks/trackers being added to areas with these slopes.
To use this functionality:
Click the 'Calculate exclusions from slopes...' button under the 'Exclusion Regions' tab in the 'Design layout' task page:
The 'Calculate Exclusion Regions from Slopes' dialog appears.
Click on the 'Selection Rectangle' map toolbar button
Click and drag a rectangle over the area you wish to explore
This should be relatively small (e.g. 5-10 km on each side) otherwise it can take a while to calculate the areas, and it may end up producing a large number of exclusion regions.
Choose the slope direction you're interested in
- All directions - takes an average of north-south and east-west into account
- North-south slopes - only takes north-south slopes into account
- East-west slopes - only takes east-west slopes into account
Set the slope threshold value
Exclusion regions will be created for areas with slopes higher than this threshold.
Click the 'Calculate exclusion regions' green button to start the calculation of the areas
It will take a few seconds to do the calculation. When it has finished exclusion regions should be added to the layout.
These exclusion regions should be sensibly named so that you can recognize how they were calculated.
If you wish to experiment with different slope directions and thresholds, do this now. If you press the 'Calculate exclusion regions' button again, any exclusion regions that have been calculated with this session of the dialog will be removed and will be replaced by the new ones.
Keeping/discarding the calculated regions
Press the 'Close (keep calculated regions)' button to close the dialog and keep all the calculated regions. These will be added to the workbook.
Press the 'Cancel (discard calculated regions)' button if you wish to discard all the calculated exclusion regions.
Here's a screenshot of a 3D scene where a layout region spans an east-west slope, and an exclusion region (in red) has been automatically calculated. The racks are thus only added where the slope is lower than the given threshold: (click to enlarge)