This image shows turbines on a wind farm in Wyoming. Three-bladed wind turbines, such as the ones shown here, are the most common because the design minimizes forces related to fatigue.
Wind turbines (DI01802)
Carlye Calvin
University Corporation for Atmospheric Research (UCAR)
image
Nature
NCAR/UCAR Image and Multimedia Gallery
Copyright University Corporation for Atmospheric Research (UCAR). By [insert name of photographer when listed], licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License, via OpenSky. For commercial use contact copyright@ucar.edu.
DI01802
http://n2t.net/ark:/85065/d7n58jgp