Wind energy is when the power of the wind provides kinetic energy to power a wind turbine that produces electricity. Wind energy has its advantages and disadvantages. Its advantages include the absence of harmful emissions, the fact that the cost to operate is about equal to a fossil fuels energy plant and cheaper than a nuclear power plant, it creates many more jobs than fossil fuels, and this energy source has the potential to be able to power the entire US with a considerable surplus (theoretically). This source of energy has its disadvantages, which include it being a localized source (possible only in windy, open areas), and it has some fluctuation in the amount of energy it produces depending on how windy it is.
Advantages
Wind energy produces no pollution because it relies on kinetic energy from a source of nature rather than using heat to make steam that then drives a turbine. Since it does not burn anything there is no pollution. It is also now just as cheap as a fossil fuel energy plant and cheaper than a nuclear energy plant. The price is down from 38 cents to 7 to 4 cents per KWh and it is still declining in price. Wind energy causes about 27% more jobs than advanced coal technology and 20 times more jobs than natural gas combined cycle. Wind has the theoretical resource of 3,000 quads (100 is the amount of quads it takes to power the US) but in reality we can only recover about 120 quads of this at this stage in wind technology.
Disadvantages
Wind power has its disadvantages, too. The first disadvantage is the that you can only use wind power in windy areas where there is plenty of space set them up (hence it would have to be in a relatively lightly populated area). The second disadvantage is that the wind isn’t always going fast enough to produce energy so you can’t always rely on wind to provide a steady supply of energy. One comment about that disadvantage is that even though it does fluctuate it normally is high enough when it is really needed (the winter is the time of the most energy usage and it is also the time when the wind is the highest so technically it is not that big of a factor).
The Wind Turbine
The wind turbine itself usually has three blades but it is entirely possible to have just two even just one blade. The length of each blade can be up to 80 meters but in developing countries it is common to see smaller blades (about 30 meters). The blades are normally made of fiberglass or wood-epoxy. Many blades travel between 10 and 30 revolutions per minute (rpm) but there are some that have a variable speed mechanism. The wind turbines have to be stopped at very high speeds to prevent damage. Many wind turbines have a gearbox but some have a direct drive (the wind is the only thing controlling the speed). There is a device called the yaw that detects wind direction and turns the wind turbine in the appropriate direction. The wind turbines can be as tall as 75 meters and as short as 25 meters. Some towers have a metal framework instead of solid steel in order to let the wind through the framework instead of eventually stopping the wind from getting to other turbines. The longer the blades the greater the power output. Right now the industry is going for the larger machines because it produces more energy at a lower cost.
There are two kinds of wind turbines. First is the pitch control (used for controlling the amount of energy produced as is the other method) and the second method is stall controlled. Pitch control works by altering the angle of the blades to match with the wind speed (and for when the wind gets too fast to operate safely it has brakes). Stall control (can also be known as passive control) relies on the original aerodynamics of the blade with no moving parts to control. When the wind gets too high it creates turbulence behind the blade minimizing power output and if the blade ever needs to be stopped for any reason there is a brake on each blade. Most wind turbines face upwind (with the tower behind the blades with the wind touching the blades before the tower) but some wind turbines face downwind (with the tower touching the wind before the blade).
The Industry
The wind industry is growing with 37,220 MW’s(MW/Megawatts are a measure of electricity) in 2004 (That is an increase of 29,620 MW’s from the 7,600 in 1997. Wind energy now powers an average of 7.5 million in the US and 16 million in Europe. There has been an estimated 40 billion dollars invested in energy of the end of 2002. The current average down-time is 1 to 2 percent of the time.
Verdict
I think the advantages of wind power far out way the disadvantages. In my opinion wind power will be a major method for energy production in the future. I think that with the industry growing like this there should be a sudden decrease in our reliance on fossil fuels. I believe that we should try to advance this technology as much as we can.
Bibliography
Harley Lee. Wind Energy: A Success Story.” http://www.endlessenergy.com/windenergy.shtml.
“Wind Energy.”
http://www.bwea.com/energy//index.html.
“Wind Energy Technology.”
http://www.bwea.com/ref/tech.html
