Wind Power

By: Riley, Kendra, Jessica and Dyson

Wind Energy

• The terms wind energy or wind power describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.

How a Wind Turbine works

• Animation: http://www1.eere.energy.gov/windandhydro/wind_animation.html

A wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity.The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. The electricity is sent through transmission and distribution lines to a substation, then on to homes, business and schools.

Pros and Cons of Wind power

Pros

• Safe

• Inexhaustible

• Inexpensive

Cons

• Wind speed variable and unreliable• Wind turbines produce large amounts of noise

pollution • Off-shore wind farms go some way to solving

these problems, but they are expensive to build and maintain. It is cheaper to put more coal into an existing power station than to build a new wind farm

Wind speed vs. Number of hours of wind

Related to variability is the short-term (hourly or daily) predictability of wind plant output. Like other electricity sources, wind energy must be "scheduled".

Environmental Effects

• Wind power consumes no fuel for continuing operation, and has no emissions directly related to electricity production. Operation does not produce carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do fossil fuel power sources. Wind power plants consume resources in manufacturing and construction. During manufacture of the wind turbine, steel, concrete, aluminum and other materials will have to be made and transported generally using fossil energy sources. The initial carbon dioxide emissions "pay back" within about 9 months of operation for off shore turbines

Land UseTo reduce losses caused by interference between turbines, a wind farm requires roughly 0.1 square kilometres of unobstructed land per megawatt of nameplate capacity. A 200 MW wind farm might extend over an area of approximately 20 square kilometres.Clearing of wooded areas is often unnecessary. Farmers commonly lease land to companies building wind farms. In the U.S., farmers may receive annual lease payments of two thousand to five thousand dollars per turbine. The land can still be used for farming and cattle grazing. Less than 1% of the land would be used for foundations and access roads, the other 99% could still be used for farming. Turbines can be sited on unused land in techniques such as center pivot irrigation. The clearing of trees around tower bases may be necessary for installation sites on mountain ridges, such as in the northeastern U.S.

Wind Energy cont’

There are many thousands of wind turbines operating, with a total capacity of 73,904 MW of which wind power in Europe accounts for 65% (2006).

Wind power was the most rapidly growing means of alternative electricity generation at the turn of the 21st century.

Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity.