| Wind power, or wind energy, is a | | | | Often wind turbines are grouped |
| renewable resource; it is from the sun. | | | | together; the arrangement in called a |
| The advantages of wind power are many, | | | | wind farm that provides energy to an |
| including practical, environmental as | | | | electrical grid. |
| well as economic. There are also | | | | Vertical axis turbines are more |
| disadvantages to using windpower, such | | | | efficient in areas with vast amount of |
| as the natural variability of wind, the | | | | lands and moderate wind speeds. Current |
| competition for other land uses, and | | | | technology is looking to develop |
| bird deaths. | | | | different turbine types for different |
| Wind power, or wind energy, is a | | | | areas of wind speed given the amount of |
| renewable resource; it is from the sun. | | | | land available for farms. |
| The intensity of solar radiation differs | | | | The advantages of wind power are many, |
| across the globe. Some areas receive | | | | including practical, environmental as |
| intense amounts of sunlight, while | | | | well as economic. Worldwide, the total |
| others receive much less. The result is | | | | kinetic energy contained in wind is more |
| a temperature gradient; a gradient which | | | | than 80 times that of human energy |
| is mediated by the flow of air to and | | | | consumption. While only a fraction of |
| from areas of dissimilar temperatures | | | | this can be used for electricity |
| and pressure systems in our atmosphere. | | | | purposes, the potential-given future |
| Uneven heating of the earth's | | | | technological developments is great. |
| atmosphere,in addition to irregularities | | | | Environmental advantages include the |
| on the earth's surface and the rotation | | | | fact that a renewable source of clean, |
| of the earth create wind. Terrain, water | | | | nonpolluting energy curbs the demand and |
| bodies, and vegetation then shape flow | | | | use of fossil fuels and emit no air |
| patterns. | | | | pollution of greenhouse gases, In the |
| The recent history of wind power in the | | | | US, wind plants have offset the emission |
| United States has a similar impetus to | | | | of than 2.5 billion pounds of carbon |
| that of alternative fuel sources in | | | | dioxide, and 15 million pounds of other |
| general - it was an idea borne from the | | | | pollutants. Also, wind energy is free: |
| 1970's Oil Crisis. It does, however, | | | | the cost of installation and maintenance |
| have a more extensive history reaching | | | | has dramatically decreased in recent |
| back into to late 19th century in the | | | | years and future technology ensures only |
| colonization of the American West; | | | | a continual decrease in the prices. As a |
| millions of windmills were erected for | | | | result, the lifetime investment is much |
| irrigation and cattle purposes to | | | | lower than most fossil-fuel systems. |
| facilitate the growing number of farms | | | | One of the primary disadvantages to wind |
| and ranches. Many soon feel into | | | | power is the natural variability of wind |
| disrepair as inexpensive energy sources | | | | in any given locale. Indeed there are |
| became more widespread and grid power | | | | certain areas with extremely high |
| extended its reach into rural areas used | | | | average wind speeds, but in most places, |
| small electric wind systems. | | | | wind exposure is quite variable. Wind |
| Outside of the US, however, wind power | | | | energy can only be stored with a |
| has a broader history. In fact, there | | | | battery, otherwise it is not. In the |
| was evidence that boats were propelled | | | | latter case, not all energy demands can |
| along the Nile as early as 5000BC via | | | | be met through the natural timing of |
| wind energy. China used wind for pumping | | | | winds. For these reasons, it may not be |
| water several millennium ago. | | | | a viable option for some. One other |
| Wind is harnessed to make mechanical | | | | disadvantage is the competition for |
| power or electricity. The kinetic energy | | | | other - more highly valued and profit |
| from the wind is converted through | | | | generating - land uses. |
| various different processes to create | | | | Economic disadvantages include the fact |
| mechanical energy that can be used in | | | | that the initial investment is often |
| lieu of fossil fuels. There are two | | | | higher than fossil fuel systems. The |
| types of modern turbines - horizontal | | | | higher costs is mostly due to the |
| and vertical axis, both of which work | | | | machinery which is involves. Other costs |
| similar to one another and as decried | | | | include site preparation and |
| above. Between the two types, they come | | | | installation. The primary environmental |
| in an array of sizes from small 100 watt | | | | drawbacks to wind power are as follows: |
| units for single homes to much larger or | | | | Noise pollution via the rotor blades |
| ones (with a blade diameter greater than | | | | Aesthetic impacts ("visual pollution"), |
| 50m). These larger turbines can generate | | | | and bird deaths. |
| 1 MW of electricity. | | | | It is important to keep in mind that |
| The most common used today are | | | | many of these problems have been |
| horizontal axis turbines with three | | | | resolved with increasing technology. |
| blades (15-30m in diameter) and produce | | | | Avian mortality, however, is still being |
| approximately 50-350 kW of electricity. | | | | studied. |