Wind Energy

Why wind energy?

• Unlimited resources of wind
• Clean alternative form of producing electricity

How does it work?

• Wind energy is essentially a form of solar energy
• Earth's spherical shape creates an uneven heating of Earth's surface
  • The air above the earth warms up and begins to rise. When it cools, the air will sink.
• Due to Corioilis effect, the air will begin to move in a circular motion, creating wind

Wind turbines

• Horizontal wind turbines
  • most common kind of wind turbines because of simpler form
  • has two or three blades and looks like a giant fan
  • the wind turns the blades, then turning on the shaft, which is connected to the generator
  • the generator coverts the kinetic energy to electricty and fed into the grid
• Vertical-axis wind turbine
  • Looks like an eggbeater
  • Two or three vertical blades rotating around a vertical shaft
  • Wind passes through the vertical blades and spins the generator, which converts the kinetic energy into electricity and fed into the grid

Location of wind turbines

• A major concern is there aren’t consistent amounts of wind throughout the day.
• In the US, mostly just the coast and the Great Plains that have better wind potential.
• Some areas are windy while others rarely experience windy days.
• National Renewable Energy Laboratory has measured and mapped wind potential in the United States.
• Areas with wind traveling 15-17 mph above 50 m is considered a sufficient amount of wind
• An area with a high wind potential will efficiently produce electricity
• if there isn't sufficient amount of wind, then utility companies will control the generators and will be dispatched up to accommodate the area
• the grid system can help send electricity to other cities

Offshore wind turbines

• A better alternative but still being researched
• Currently, US does not have any off-shore wind turbines
• High wind potential and speeds above the ocean
• Doesn’t take up land space

Wind energy in the U.S.

• Wind farms can generate 5,200 megawatts of electricity, providing power to 1.5 million American households.
• As of 2007, Texas is the leading state in using wind energy.
• Generated 5,000 megawatts

Concerns about wind energy

• Environmentalists have noticed an increase in deaths of birds and bats in areas with wind turbines
• top 3 locations in California: Altamont, Tehachapi and San Gorgonio
• Almost 1000 birds have been killed each year at the sites
• about 3-11 birds killed per turbine per day
• blades spin so fast that as bird approaches turbine, the can't see the blades (spin up to 180 mph)
• birds and bats don't die immediately but their lungs are ruptured when caught in the wind's vortex
• The American Wind Energy Association researched the causes of deaths of birds
  • “Summary of Anthropogenic Causes of Bird Mortality”
• Research found that of every 10,000 birds that died due to human activities, 5,500 birds have died from buildings and windows. Only 1 of the 10,000 birds died from wind turbines

Conclusion

• Wind energy needs to be further researched
• Wind energy can provide an environmentally friendly form of electricity
• Unlimited resource
• Zero emission of green house gases