Fossil Fuel Formation and Energy Resources

Fossil Fuel Formation

• Fossil fuels are carbon-based fuels formed millions of years ago from the decay of living matter.
• Coal is formed from plants, while oil and natural gas are formed from sea creatures.
• Formation of coal involves:
  • Huge forests growing millions of years ago
  • Vegetation dying and forming peat
  • Peat being compressed between layers of sediments to form lignite (low-grade coal)
  • Further compression forming coal
• Formation of oil and natural gas involves:
  • Small animals and plants dying and falling to the bottom of the sea
  • Sediments covering their remains
  • Sediments forming layers and changing into sandstone as temperature and pressure increase
  • Heat and pressure turning remains into crude oil and natural gas
  • Oil and gas separating and rising through the sandstone, filling in the pores

Energy Resources and the Generation of Electricity

• The demand for energy is increasing worldwide due to:
  • Increasing population size
  • Increasing industrialization and urbanization
  • Improvements in standards of living and expectations
• Types of energy sources:
  • Non-renewable:
    • Limited
    • Take millions of years to get replenished
    • Examples: fossil fuels (coal, oil, and natural gas), nuclear power
  • Renewable:
    • Can be used over and over again
    • Can be replenished in a short period of time
    • Examples: geothermal power, hydro-electric power, tidal power, wave power, wind power, solar power, biofuels (e.g. bioethanol, biogas, and wood)

How Energy Sources are Used to Generate Electricity

• Fossil fuels and biofuels:
  • Combustion produces a massive amount of energy used to heat water and convert it into steam
  • Steam drives the turbines
• Nuclear power:
  • Uranium releases huge amounts of energy when nuclear fission (splitting of the atom) occurs
  • Energy is used to heat water, produce steam, and rotate the turbines
• Geothermal power:
  • Uses hot rocks to heat water
  • Hot water returns to the surface under pressure and heats the second supply of water using a heat exchanger
  • Steam produced in the second supply moves the turbine, generating electricity
• Tidal power:
  • Uses the natural rise and fall in the level of water in an area
  • Water is held back by a tidal barrage (a small dam that releases water back through a turbine)
• Wave power:
  • Uses smaller differences in water levels caused by wind
  • Uses turbine and generator
• Hydro-electric power:
  • Uses a dam on a river to store water in a reservoir
  • Water is released from the reservoir that flows through the turbine, rotating it
  • Turbine activates a generator that generates electricity
• Wind power:
  • Wind turbines have shafts (blades) that rotate due to wind
  • Gearbox maximizes the rotation of the shaft
  • Brakes slow down or stop the rotor in very windy conditions, preventing damage to the blade
  • As the turbine rotates, the generator produces electricity
• Solar power:
  • Uses photovoltaic cells that produce a small electric charge when exposed to light
  • A bank of cells organized into solar panels produces a significant amount of electricity