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 = 1kWh)
• It would take 300 people producing 100W each to power a house that consumes 30kW
• The average power consumption in UAE is 10kW/person
• Per capita energy consumption in the USA is 6x more than the world average
• Energy Intensity


  Energy use per $ GDP, higher for manufacturing, lower for services
• Energy intensity over time


  Decreases due to regulation, environmental policies, and shift to other energy types
• Life expectancy


  Increases with energy consumption up to a certain level, then additional energy does not improve quality of life further
• Major sectors of energy consumption


  • Residential
  • Commercial
  • Industrial
  • Transportation
• 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 99.9%
• Fossil fuels (oil, coal, gas) account for 87% of global primary energy
• Removing some sulfur content from coal is an example of improving primary energy sources