Horizontal Axis Wind Turbines
Horizontal axis wind turbines have been the standard for years as opposed to vertical axis wind turbines, which are now gaining favor with homeowners. Horizontal axis wind turbines, as the name implies turn on a horizontal axis or axel.
|Some people still call these windmills and some still have blades of old and are in a farm setting. But, the windmills of yesterday are not the same as the horizontal axis wind turbines of today.|
For example, most large utility scale wind turbines such as the ones you’ll find on wind farms use a horizontal axis. Utility scale horizontal axis wind turbines typically use three blades although some are now being developed that use just two.
Railed against by some environmentalists as “bird Cuisinarts” the utility scale horizontal axis wind turbines today are being designed to move at slower speeds and be more visible to our fine feathered friends. But, large utility scale horizontal wind turbines are not the only games in town.
Residential wind turbines that use a horizontal axis are also coming of age. These small wind turbines will typically turn at lower wind speeds and may be mounted in the backyard or on the rooftop.
Like many residential wind turbines for home use, the owners of a horizontal turbine may have to fill out zoning paperwork and / or get permission from one’s homeowner association to place the device on one’s roof or in one’s yard (It’s recommended to get this information upfront before buying or building your own).
The horizontal axis wind turbines (HAWT) need to be pointed into the wind for optimal efficiency. The utility scale turbines may do this by using a sensor and servo motor, while the smaller turbines simply use a wind vane (tail-fan) to keep pointed in the right direction.