Week 4: Wind Turbines

 My main takeaways from this week's focus topic/unit: 

Book Notes

  • What are wind turbines? 
    • Wind energy = important & growing source of renewable energy 
    • Wind turbines convert kinetic energy from wind --> mechanical energy through rotational movement of blades. Electric generator converts mechanical energy from spinning blades to electric energy that can be used to power many sources
  • Wind energy is a form of kinetic energy
  • Rotation of blades (turbine) & gear box is a form of mechanical energy 
  • Generator has a spinning rotor causing a rotating magnetic flux inside stator of coils to create current as a form of electrical energy (induction) 
  • How do wind turbines create electricity? 
    • Blades capture air & spin 
      • Bernoulli's principle: molecules have farther to go over the top of a wing * therefore travel faster. Greater speed provides less pressure than forces on the bottom of the wing, and plane is pushed off the ground. 
    • Wind comes from uneven heating of Earth's surfaces due to color differences 
Lecture Notes 
  • Modern turbines vs. windmills 
    • Both harness kinetic energy in the wind to do work 
    • windmills convert wind energy into torque for pumping water or grinding flour 
    • modern wind turbines spin a generator to produce electricity. This requires less torque, more shaft speed 
  • How a wind turbine works 
    • wind turbines convert kinetic energy from blowing wind into electricity 
    • the wind pushes turbine blades to rotate around a central hub 
    • this rotation turns a generator which produces more energy 
    • faster the generator spins: more electricity it produces 
  • Why do modern turbines use 3 blades? 
    • 4 bladed turbines weigh & cost more produce = less cost effective 
    • 2-bladed are capable of spinning faster & make more electricity than 3 bladed, but can have balance issues 
    • 3-bladed: sweet spots, efficient & cost effective, operate quieter
  • Problems with wind power today 
    • Transmission problems
      • power production not located around major population centers 
        • sound & visual impacts 
        • "not in my backyard" mindset 
  • The future of wind power
    • Offshore wind power places energy production much closer to major population centers 
      • 2 blades 
      • offshore wind farms have fewer impacts on neighbors 

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