The term "wind energy" describes the process by which wind is used to generate electricity.Wind energy is a free renewable resource and also a source of non-polluting electricity.

 

According to the U.S. Department of Energy, in 1990, California's wind power plants offset the emission of more than 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality. Over the past five years the averag growth rate has been 27.6% per year. More than 200 GW of new wind power capacity were instaled by the end of 2013.

 

Besides the US, Denmark, the UK, Ireland, Germany and China have become key-players. Yet, other countries catch up at a fast pace.

 

Wind resources are characterized by wind-power classes, ranging from class 1 (lowest) to 7 (highest). Class 3 is considered good with an averaeg annual wind speed of at least 13 miles/hr. This is found in many locations in Germany, Poland and Southern Romania.

 

Also, the wind speed is a critical factor in wind energy, as the energy generated is proportional to the wind speed.

 

However, one draw back of wind turbines is the variability of wind for each individual one. This deficit is offset in large wind parks, as the totality of turbines provide the total power generated.

 

Another critical factor is the capacity factor, referrering to the actual production of energy in relation to the maximum. Typical capacity factors are 15 - 15%.

 

Wind parks have several tremendous advantages vis-a-vis other renewable energy sources:

 

- once set up ( which is initially capital-intensive), they require little maintenance cost.

- no fuel cost

- little impact on agricultural areas

- re-powering is possible

- high yields