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WIND ENERGY
Lesson 3B
Adapted from: http://www.eia.gov/kids/energy.cfm?page=wind_home-basics (United States
Energy Information Administration) January 2016
Energy From Wind
Wind is caused by the uneven heating of the earth's surface by the sun. During the day, the air
above the land heats up faster than the air over water. The warm air over the land expands and
rises, and the heavier, cooler air rushes in to take its place, creating wind. At night, the winds are
reversed because the air cools more rapidly over land than over water.
How uneven heating of water and land causes wind
Electricity Generation From Wind
How Wind Turbines Work
Wind turbines use blades to collect the wind’s kinetic energy. Wind flows over the blades
creating lift (similar to the effect on airplane wings), which causes the blades to turn. The blades
are connected to a drive shaft that turns an electric generator, which produces electricity (see
illustration on page 2).
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WIND ENERGY
Lesson 3B
Wind Turns the Blades Which Turn the Generator to Make Electricity
Source: Google images
Wind Power Plants Require Careful Planning
Operating a wind power plant is more complex than simply erecting wind turbines in a windy
area. Wind power plant owners must carefully plan where to position wind turbines. It is
important to consider how fast and how often the wind blows at the site.
Wind speed typically increases with altitude and increases over open areas without windbreaks.
Good sites for wind turbines include the tops of smooth, rounded hills, open plains or shorelines,
and mountain gaps that funnel and intensify wind. The Columbia River Gorge in Oregon is a gap
in the mountains; wind funnels through the gap activating wind turbines located on the rounded
hills above the Columbia River.
Offshore wind power
There is potential for significant electricity generation from wind energy in the waters off the
coasts of the United States, and there are plans for several offshore wind project along the shores
of the northeastern U. S. There are many off-shore wind energy projects operating in Europe.
Wind Turbines and Wind Farms
The size of wind turbines varies widely. The length of the blades helps determine the amount of
electricity a wind turbine can generate. Small wind turbines used to power a single home or
business may have a capacity of less than 100,000 watts. The largest turbines have capacities of
five to eight million watts. Larger turbines are often grouped together to create wind power
plants, or wind farms that provide power to electricity grids.
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WIND ENERGY
Lesson 3B
One of the world's largest wind farms, located in Texas, has 430 wind turbines spread over about
47,000 acres.
Cost of producing electricity from wind
New technologies have decreased the cost of producing electricity from wind, and growth in
wind power has been encouraged by government and industry incentives and subsidies. About 4
percent of U. S. electricity generation is from wind. The federal government provides research
and development funding to help reduce the cost of wind turbines. The U.S. federal government
also has offered tax and investment incentives for wind power projects.
Types of Wind Turbines
Most of the wind turbines currently in use are horizontal-axis turbines. Horizontal-axis turbines
have blades like airplane propellers. The horizontal-axis turbines used on wind farms can be as
tall as 20-story buildings and can have blades more than 100 feet long. Taller turbines with
longer blades generate more electricity. Horizontal-axis turbines commonly have three blades.
Source: National Energy Education Development Project (public domain)
Wind Energy in Oregon
Oregon now ranks among the top ten states with the most wind power installed. Climbing from
1 percent in the early 2000s, wind power accounted for 12.4 percent of total electricity generated
in Oregon during 2013. Most of the wind turbines are located in the Columbia Gorge and in
northeastern Oregon. Lesson3BWINDHandout.1.2016
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Team Member Names_________________________________________________
List a positive
environmental impact and a
negative environmental
impact of using wind energy
to make electricity
Lesson 3B
WIND: Renewable Energy Analysis Worksheet
Positive Environmental Benefit:
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Negative Environmental Impact:
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
In your opinion, rate from 1
to 5 how cost effective wind
is as a source of energy for
people in the United States.
Provide at least two reasons
why you chose this rating.
Rating of 1: very cost
effective; it is easy to change
wind into electricity with
wind turbines; it is easy to
find locations for wind
turbines; costs for materials
to make electricity from
wind energy are reasonable
Rating of 5: not cost
effective; difficult to find
locations for wind turbines;
electricity created from wind
is costly to transport to the
user; costs for materials
necessary to make electricity
from wind energy are not
reasonable
Your analysis of wind as a
source of energy in the
United States:
COST EFFECTIVE?
Rating = ________
Reason #1: __________________________________________________________
___________________________________________________________________
___________________________________________________________________
Reason #2:__________________________________________________________
___________________________________________________________________
___________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
Lesson3BEnergyAnalysisWkshtWIND.1.2016