Rooftop Photovoltaic Potential Estimation Tool for QGIS

Required Tools and Libs

Tools

• Python 3.12 or higher
• QGIS Desktop 3.34 or higher
• Installed QGIS plugins: GRASS 7, QuickOSM

Python libs

• os (loading and saving data files)
• csv (table data output)
• qgis.core (main API for contacting qgis)
• qgis.utils (Canvas tools API)
• osgeo (gdal tools)
• grass.scripts && grass.scrips.setup

Code Structure

HV_Transmission_Line_Analysis/
├── main.py                     # main execution script
├── constants.py                # Static Data and Strings  *on check for refactor*
├── basic_raster_loader.py      # script for loading raster into QGIS *marked for called method*
├── QGIS_reader_offline.py      # reader of offline raster *marked to Class based file* 
├── QGIS_reader_WMS.py          # reader of online raster *marked for refactor*
├── roof_analysis.py            # script for roof dividing *marked for refactor*
└── data/
    ├── test_raster.tif         # testing input file
    └── tmp/                    
        ├── aspect.tif          # updatable raster of aspect
        ├── output.tif          # output variant of file
        ├── slope.tif           # updatable raster of slope
        ├── aspect_points.csv   # updatable table of aspect *marked for refactor*
        └── slope_points.csv    # updatable table of slope *marked for refactor*

Main methods

Render_Set Method

Method applies more efficient render style for loaded layer.

glob_rad_check Method

Method uses grass region parameters to apply sun insolation simulation for choosen date and time.

overpassApi_roof_finder Method

Method applies OverpassAPI to find and separate roof detected on the loaded layer.

roof_pv_check Method

This method applies and calculates all the nessecary conditions for detected roofs. (flat, slope and aspect)

Actual tasks:

1. Process automated loading of rasters into QGIS via Python script (completed on 01/10/2025)
   • as an offline file.
   • via WMS service.
2. Add coordinate boxing for online WMS raster. (working only manually 12/11/2025)
   • Basic tools >>> failed;
   • GDAL >>> null pointer in output;
   • GRASS environment >>> testing;
   • Cropping offline WMS dataset;
   • Reloading WMS to offline dataset;
3. Analysis of tilt and turn of roof parcels in boxing zone. (Completed on 3/12/2025)
   • Global radiation analysis (slope and aspect) via r.sun.insoltime;
   • Roof angle analysis output to cvs;
4. Differentiation of roof vectors via QuickOSM. (completed on 15/12/2025)
   • Installed QuickOSM plugin;
   • Created 'roof_finder' method, that downloads and creates roof polygons via OverpassAPI;
   • Implemented roof rastering and cutting out to 'roof_finder';
   • Refactored gdal_aspect_slope into roof_pv_check due to easier calculation;
   • Added flat roof check;
   • Implemented PV suitability check for roofs;
5. Complete PV analysis and structured output. (in process)
   • Coloring of suitable roofs;
   • Table/CSV output;