How Efficient is Wind Energy?
To answer the question of how efficient is wind energy involves looking at many various pros and cons of creating electrical power by using the kinetic energy of the wind.
In reports published by pro-wind energy groups, it was highlighted that in the past two years more power generating capacity using wind turbine technology were added in the U.S. than new coal- fired power generation.
That sounds quite impressive except when you realize no new coal-fired power plants have been added for many years. Wind energy is new and growing. Traditional power plants may be declining.
Progress
New ideas are constantly being developed to create truly efficient wind energy technology. One of the latest proposals is a totally new design for placement of the support towers in a wind farm.
The prevailing wisdom is that there must be a good amount of space between the wind turbines so that maximum wind energy can be captured. Now that standard design is questioned and new wind farms will be configured in a different way that will place them much closer together.
Asking How Efficient is Wind Energy
Producing electricity from the wind is capturing the kinetic energy wind possesses and converting it to a usable power supply. One of the hardest problems to overcome is the transient nature of wind. Wind is not dependable as the strength and speed of the winds flowing across the land change constantly.
A wind turbine processes energy best when the wind flow is steady. In turbulent weather wind gusts and wind shear reduce the efficient of wind farms.
This basic problem is being addressed by scientists and engineers who are working on new designs to increase the efficiency of wind turbines to deal with winds that are seldom the perfect, steady source of power best for those turbines.
Looking at how efficient wind energy might become in the future, specialists are considering how air flows over the propeller blade of the turbine.
If controllers can be built that transmit information in real time, the propellers may be able to adjust to use the air flow more efficiently. An improved control for the turbines might also reduce the vibrations that are often a problem and lesson the noise level.
At Syracuse University a team has been working on improve airfoil lift and reducing drag on the propeller blades when air flow becomes unsteady or gusts are produced. Drag is the resistance transmitted to the propellers as they slice through the air.
University of Minnesota scientists are working on designs to reduce drag by placing grooves on the propeller blades. The grooves are so tiny they cannot be seen with the naked eye but are a series of triangular depressions meant to help wind flow over the blade more easily.
This innovation is much like racing sailboats where drag was reduced by several percentage points with a grooved sail fabric. For efficient wind energy, the new grooved propeller blades could improve efficiency of the wind turbine by as much as 3%.
The Noise Factor
If you wonder "how efficient is wind energy" you are asking if power is being produced and the answer to that is yes. However, there are other factors such as those mentioned above that can affect how efficient wind energy is by examining problems that call for solutions going forward.
Noise as it applies to wind farms is an odd problem because it is difficult to predict. You may stand at the base of a wind tower and hear only a light swish of propellers cutting through the air.
Much farther away, people to the East of the wind farm might heard much louder sounds while those of an equal distance I another direction might hear nothing. What is not understood is the interaction of the blade or the factors of turbulence that can make wind farm noise much louder.
Wind Turbine Syndrome
Some people are very sensitive to low-frequency vibrations. When exposed to this noise level some symptoms often reported are migraine headaches and balance problems (inner ear problems).
This sensitivity to certain sound levels is reported in between 5 and 24 percent of the population. This low frequency noise is the type of sound generated by wind turbines. Doctors recommend wind turbines be located at least 1 ½ miles from any inhabited structure.
Low frequencies produce a high level of vibration which may be transmitted to inner ear and this is most like caused of what is called wind turbine syndrome.
Although doctors have determined there are no ill effects from the frequencies associated with wind farm noise that is not helpful to someone suffering daily migraine headaches.
Other people complain of the noise of a wind turbine but have no ill effects. It is the constant sound that bothers them but there are no physical hazards involved.
One thing is certain. The low sounds that are sometimes created by an active wind turbine may be bothersome to a minority of the population but are much better for your health than an oil spill or a radiation leak from a nuclear power facility. When asking how efficient is wind energy you must also consider safety.
