How to upload your topography

Learn how to upload your topography files to pvDesign and how to convert from CAD to the admitted files

Introduction

Hi fellow pvDesigners!

As you all know, getting to know the shape of the terrain of PV projects is something crucial to decide if a site is feasible for construction or not. In order to do this analysis, we need the elevation data of our site. pvDesign gives two possibilities for this:

  • The first option is using Google Earth elevation data. The database used in this service is the SRTM-30, it has global coverage and a resolution of 30x30 meters.
  • The second option is uploading your own topography. As the resolution of Google Earth elevation may not be as accurate as we need for this kind of analysis, this option will allow you to upload a more detailed dataset from other geographical services or from your own topographical surveys.

This information, regardless of the source of the data, will be used to represent your terrain with our slope map and to decide if your mounting structure complies with the restrictions of slopes and post length.

How to upload your topography files

Uploading your topography data

In this article, we are going to focus on how to upload your topo files to our software. You'll find the topography section in the location tab in "Start Design". A card with the Google Earth data will be always available and on the left-hand side, you'll find the upload button "+". Once your file is uploaded, a new card will appear and this card will be available for all the new designs of that project.

The file has to comply with the following requirements:

  • The admitted formats are plain text files (.csv, .txt, .xyz) with elevation data
  • Each line corresponds to an elevation point (XYZ format), in UTM coordinates. The first column corresponds to the X coordinate (easting), the second to the Y coordinate (northing), and the third to the elevation value in meters.
  • The file should not have headers.
  • The coordinates should belong to the same UTM zone as that of the project
  • The data coverage area should roughly match the site area.
  • The file does not exceed the maximum file size of 100 MB.

Converting CAD files to CSV with QGIS

Isolate layers in a new .DWG file

This step is not necessary but it will save you time. Topography files are usually heavy and QGIS will take time to open them. For that reason, it is better to create a new drawing in AutoCAD and paste from the origin only the information requested (contour lines).

  1. Open your .DWG file with all the information. 
  2. Isolate only the contour lines
  3. Create a new drawing in AutoCAD.
  4. Paste from the origin the contour lines in the new drawing. You should use the command: Pasteorig (or Pegarorig in Spanish).
  5. Save the new draw as 2013 dxf or 2013 dwg.

Open DWG in QGIS

Go to Project >> DWG/DXF-import

In order to make it work, you can follow these steps:

  1. Create a new/load an existing Geopackage with a fitting CRS
  2. Import DWG-file
  3. Check 'Expand block references' and 'Use curves' if needed
  4. Set 'Group name' of your choice
  5. Uncheck unwanted CAD-layers (Choose only the ones with contour lines)
  6. Checking 'Merge layers' is advised

Extract Vertices

Go to Vector >> Geometry tools >> Extract Vertices

  1. Use a temporary layer to save those points

Save as CSV

Right-click over Vertices layer >> Export >> Save Features as…

  1. Format >> Comma Separated Value [CSV]
  2. File name >> Select folder and give a name
  3. Select fields to export… >> Deselect all fields to export
  4. Layer options >> Geometry >> As_XYZ

Check the CSV

Remember to meet the following requirements

  1. The first column corresponds to the X coordinate (easting), the second to the Y coordinate (northing), and the third to the elevation value in meters.
  2. The file should not have headers.
  3. The coordinates should belong to the same UTM zone as that of the project.
  4. The data coverage area should roughly match the site area.
  5. The file does not exceed the maximum file size of 100 MB.

Review the CSV file. QGIS includes a header (X, Y, Z). Remove it. 


Feel free to contact us at support@ratedpower.com if you have any other questions.