Some of the very first windmills were vertical windmills that dated back to the 800s in Persia, now known as Iran. They were pretty simple to build and maintain since they were mounted close to the ground.
They had long vertical drive shafts with rectangle shaped blades. Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind corn and pump water.
Vertical wind turbines are mounted on a vertical axis. They have a main rotor shaft arranged vertically. These wind power generators have blades that go from top to bottom and look like giant egg beaters. Vertical axis windmills will turn no matter which way the wind is blowing which means they can be mounted in a stationary position.
Another advantage of vertical wind turbines is that they can be mounted fairly close to the ground which makes it much easier to maintain them. You don’t have to lower the windmill down or climb a long ladder just to fix something. A typical vertical wind turbine stands at about 100 feet tall and about 50 feet wide compared to a typical horizontal wind generator that stands as tall as a 20-story building and has blades 200 feet across.