WTG Shadow flicker
How many hours of shadow
will fall on each house?
Shadow flicker from wind turbines calculated for each receptor and for the whole area around the wind farm – in the “worst case” scenario according to the LAI guidelines, directly on the project layers in QGIS.
Illustrative diagram with sample values – an illustration of the results, not a screenshot of the plugin.
The answers you are looking for
Three questions, one plugin
Results
Ready for the report, straight in the project
Total hours at receptors
A CSV file with the annual flicker time for each receptor.
| Receptor | h/year |
|---|---|
| B2 | 54 h 00 min |
| B5 | 40 h 00 min |
| B3 | 21 h 56 min |
Calendar of events
Each event with its start and end, in UTC and Polish time. Also as an Excel file (XLSX).
| Rec. | Day | Start | End |
|---|---|---|---|
| B2 | 14.01 | 08:12 | 08:31 |
| B2 | 15.01 | 08:13 | 08:30 |
| B3 | 03.03 | 17:02 | 17:21 |
| B6 | 21.11 | 15:18 | 15:34 |
Extent map
A raster of hours per year, added to the project with ready-made styling in 5-hour classes.
Working in QGIS
Three layers and one click
Turbines only need the hub height and the rotor radius or diameter. The plugin reads the terrain elevation at each receptor and in each raster cell from the DTM.
PDF report
PDF report in a few clicks
The report is built from the results already calculated and does not run new calculations. You choose the sections, and the plugin assembles them into a single PDF file.
Map and receptor table
An A4 page with a receptor map and a table of annual totals, sorted from the highest values.
Calendar of events
A4 pages with a dense, multi-column calendar in Polish time – to keep the report as short as possible.
Extent map
An A3 page with a raster map of the area affected by shadow flicker and a legend of classes.
Method
Precise where it matters
- Worst case according to LAI. The rotor always perpendicular to the turbine–sun line, the window always facing the turbine.
- Analytical at receptors. Exact start and end times of each event, rather than sampling “every minute”.
- Precise sun position. NOAA algorithm, taking into account the sun elevation threshold of 3° above the horizon.
- Efficient on the grid. The map is calculated in vectorised form on the whole grid at once, with calculations clipped to the theoretical range of the turbines.