lecture 3

• Energy


  The capacity to do work
• Work


  Force (N) x Distance (m)
• Joule (J)


  The amount of energy transferred when a Force of 1 Newton is applied to an object and moves it a distance of 1 meter
• Power


  The rate with which we use energy, measured in Watts (W)
• Watt (W)


  1 Joule per second (J/s)
• An average person can sustain about 100W of power output for at least a moderate amount of time
• kW


  1000 Watts
• Difference between kW vs kWh


  1. kW is the rate of energy use (power)

  2. kWh is an amount of energy (1000W x 1hr = 3.6MJ = 1kWh)
• It would take 300 people producing 100W each to power the house
• Many things we depend on today use a lot of power
• The average power consumption in UAE is 10kW/person
• Per capita energy consumption has increased significantly since 1800
• Energy Intensity


  Energy use per $ GDP
• Higher energy intensity


  Lower energy efficiency
• Energy intensity over last 100 years


  Decreasing in US, decreasing globally
• Life expectancy


  Increases with energy consumption, up to a point
• Primary energy


  Input of raw fuels (e.g. oil, coal, gas, nuclear fuel)
• End-use energy


  Energy that actually reaches the end-use (e.g. gasoline in the car, electricity in the house)
• Sources of primary energy (World)


  • Oil 33%
  • Coal 30%
  • Gas 24%
  • Hydro 6.8%
  • Nuclear 4.4%
  • Other 2.5%
• Sources of primary energy (UAE)

  • Fossil fuels 98%