Wind Turbines

							Wind Turbines
How does wind produce electricity?
Draw what you think a wind turbine
           looks like.
Photo by Wendy Francesconi
Photo by David Carroll
    Facts about large wind turbines
• Cost 1.2 to 2.6 million dollars each
• Rotors up to 90m in diameter on land and 110m on
  water
• Rotors spin 15 to 50 rotations per minute (rpms)
• Each generates up to 2 megawatts of electricity
  (that’s enough power for 600 houses!)
Photo by David Carroll
      Facts about small wind turbines
•   Cost 3000 to 6000 dollars each
•   Rotors only a couple meters in diameter
•   Rotors spin 175 to 500 rotations per minute (rpms)
•   Produce one kilowatt of electricity (a little less than
    what is needed to power most houses)
           Wind Turbine Safety
• Have built-in brakes for when the rotor goes
  too fast

• Kill 40,000 birds annually
  – But cats and power lines each kill 100’s of millions
Find pictures online of all sorts of wind
   turbine designs—small and large,
 vertical and horizontal, real ones and
 plans for new kinds—and show them
     here to encourage discussion.
        Wind Turbine Animation
http://www1.eere.energy.gov/windandhydro/wind_animation.html
    Wind Turbine Diagram with Labels
http://energiaeoliana.wordpress.com/2008/03/13/how-a-wind-turbine-works/