DISNEYLAND IN SPACE
WHAT IS WIND
Wind is air in motion. It is produced by the uneven heating of the earth’s surface by the sun. Since the earth’s surface is made of various land and water formations, it absorbs the sun’s radiation unevenly. Two factors are necessary to specify wind: speed and direction.
WHAT CAUSES WIND TO BLOW
As the sun warms the Earth's surface, the atmosphere warms too. Some parts of the Earth receive direct rays from the sun all year and are always warm. Other places receive indirect rays, so the climate is colder. Warm air, which weighs less than cold air, rises. Then cool air moves in and replaces the rising warm air. This movement of air is what makes the wind blow.
WIND ENERGY GROWTH
Wind energy is one of the fastest growing energy sources in the world. In the United States, the installed capacity of wind energy grew by an incredible 45% in 2007 and another 50% in 2008. The United States installed 8,358 MW of new wind energy in 2008. Wind energy is growing at this rate because the cost of electricity produced by wind energy is competitive with electricity produced by natural gas, oil, coal, or nuclear power. Also, wind energy is a clean, renewable technology that does not contribute to global warming. This makes it a healthier, more sustainable choice than other forms of electricity generation.