Wind Turbine Facts
A wind turbine converts the mechanical energy of wind into electrical energy using an electric turbine generator that is fueled by the spinning blades of the wind turbine.
It depends on wind speeds, the size of the blades and turbine, and the air density. Betz’s law shows us that a maximum 59.3% of the kinetic energy of the wind can be converted into electricity. The capacity factor for a large modern wind turbine is around 2MW. But this is a theoretical and maximum value of electrical output because the average wind turbine produces output at around a 20%-30% efficiency rate.
The blades of wind turbines are designed with a similar aerodynamic model to an airplane wing. The blades are designed to create an aerodynamic and rotational lift as wind passes over.
The two most broadly defined types of wind turbines are horizontal-axis wind turbines (HAWT) and vertical-axis wind turbines (VAWT). The HAWT is the more commonly used type of wind turbine, a style one will often see in modern day wind farms.
This is a rating system used to rate the quality of a location of a wind turbine. Higher average wind speeds bring higher power class rating numbers. Wind speed is a huge factor in the efficiency of the location of a wind turbine.
Wind is the movement of a parcel of air within the earth’s atmosphere that always flows towards lower pressure areas. Wind is described by both it’s speed and direction.
7. Wind Speed
Wind speed can be measured using an anemometer. Wind speed has a cubic relationship with electrical output of a wind turbine. Higher wind speeds are more desirable for wind turbines, although extremely high wind speeds can be dangerous for most wind turbines. The cut-in speed of a wind turbine is the minimum wind speed needed to for a wind turbine to begin to generate electricity.
8. Tip Speed
The speed of the tip of a wind turbine blade is important for determining the optimum number of blades that a wind turbine needs. Every point on a wind turbine blade rotates with the same angular speed. Linear speeds of wind turbine blades are the highest at the tip.
9. Wind Maps
Wind maps are great tools for locating exceptional wind for wind turbine construction.
Wind turbines were not actually created until the late 1800’s, but the history of wind power dates back centuries through the ancestor of the wind turbine, the windmill. A windmill is different from a wind turbine because they do not generate electricity, they are were originally designed to grind grains or pump water. The first windmill converted into a wind turbine (by adding an electric turbine generator) was in 1887 in Cleveland Ohio, designed by Charles F. Brush.
By the end of 2011 the United States had just less than 43,000 MW of wind energy capacity. A huge increase from the 2,500 MW in the year 2000. Clearly, wind energy today is a growing resource of renewable energy.
Wind energy is a fast growing resource.
Wind turbines do not emit any pollutants during operation, however there are usually pollutants emit during the construction process. They do not require a lot of land space for construction which is a major benefit to farms who can use the remaining ground space for farming or grazing. Wind turbines do have a few negative impacts on the environment: they can be dangerous for birds, and they can be a noisy nuisance for nearby residents.
The single greatest advantage of wind turbine is that operation cost of the turbine is theoretically zero. This advantage is what allows renewable energy systems like wind turbines to be a cost-effective long term investment.
Wind turbines produce two different types of noise pollution: aerodynamic noise, and mechanical noise. Wind turbine noise can be physically and psychologically dangerous to nearby residents.
A wind turbine shadow flicker is the shadow casted by the moving blades of a wind turbine. Shadow flickers that infiltrate nearby homes can be physically or pshycologically distracting.
Wind turbines are expensive. The initial cost of a wind turbine is the greatest cost to the buyer. Eventually wind turbines can save you money from lowering the cost of your electric bill, but this make take years of operation before you see a payback on your investment.
The federal government offers tax rebates of up to 30% of the cost of a qualifying wind turbine.