The interesting world of VAWTs
I was curious about the type of wind turbines that do not need to face into the wind. So I googled around to learn they are called Vertical Axis Wind Turbines (or VAWTs). But that is not all there is to it. There are a handful of different designs built around two basic concepts: drag and lift. And as you can guess, these are not as efficient as the more popular Horizontal Axis Wind Turbines (HAWTs) found on most wind farms. The beauty of the VAWT is their simplicity: Just a special shape the wind will rotate and, if connected to a generator, it could be used to produce energy too. But its power-generation capability is somehow smaller (if you consider the frontal area it presents to the wind) than the propeller rotors of the HAWTs. On the other hand, some of the designs, have been created quite simple so they can be built repurposing other objects. For example, the basic Savonius rotor can be built by joining two halves of an oil barrel in an S-shape configuration. Any other c