The type of wind turbine you’re used to seeing in stock photos of wind farms is called a horizontal axis wind turbine (or, HAWT). But there is another form of wind power, called a vertical axis wind turbine (VAWT), in which the blades rotate on an axis perpendicular to Earth’s surface. This type of turbine can work better in unstable wind conditions because they don’t need to be pointed into the wind, but still produce much less electricity and durability problems because of the force the wind exerts on them. That’s why you would only see VAWTs in small applications, like homes, and HAWTs in wind power farms.
Image: World Wide Wind