Do not operate the form until this page and its programme have loaded completely. Otherwise the program will complain about missing data, and you will have to click Reload. This calculator lets you experiment with your local conditions to determine the shape and size of the local area which may be affected by shade (light flicker) from a wind turbine. For an actual project you will probably want professional wind project software which will help you with a lot of other aspects as well. (See the Links section).
After changing data, use the tab key, click the Calculate button, or click anywhere on the page outside the field you have updated to get the results in the right column. To get a plot image, click on the Plot button. Click on the question marks for help. (If a plot windows disappears, it is probably hidden behind this window).

Select: Select Location Amsterdam Anchorage Ankara Athens Beijing Berlin Bombay Boston Boulder Brussels Cairo Canberra Cape Town Chicago Christiansø *) Copenhagen *) Dallas Dublin Edinburgh Esbjerg Helsinki Hong Kong Honolulu Lisboa London Madrid Manila Melbourne Mexico City Montreal Moscow New Delhi New York Nuuk Oslo Ottawa Paris Perth Reykjavik Rio de Janeiro Rome San Francisco Seattle Shanghai Singapore Stockholm Thorshavn Thule Tokyo Viborg *) Warsaw Wellington Zurich Other or type
°' latitudeNorth South
°' longitudeEast West

° time zone meridianEast West
or GMT + - 0 1 2 3 4 5 6 7 8 9 10 11 12 : 00 30

day month
time (0:00-23:59) : Daylight saving time

m hub height, m rotor diameter

Sunrise :
Noon :
Sunset :
Declination °
Sunrise/sunset duration
min. sec.

Solar azimuth °
Solar altitude °
Direction from the sun

(East, North, Up coordinates)

this...minute hour day month year, step 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 20 30 40 60 minute(s)
Plot area height width pixels, resolution = m per 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 pixels
Rotor direction (azimuth) random worst case (Darrieus)
facing azimuth ° = N/S NNW/SSE NW/SE WNW/ESE W/E WSW/ENE SW/NE SSW/NNE Other use wind rose table below
Turbine running % of the daytime. Max. distance m
Sunshine % of the time OR check here to use monthly sunshine hours from table below.
Include mouse sensitive shadow duration readout (only useful if used with an I.E. 4 browser)

*)= Cities marked with an asterisk in the city popup menu include sunshine and wind rose data for the tables below.

To print the results of the plotter programme you should make a screen dump