Physics Topic 8: Energy, Power and Climate Change

Thermal energy may be completely converted to work in a single process, but continuous conversion of this energy into work requires a cyclical process and the transfer of some energy from the system

Energy no longer available to perform useful work, usually lost to surroundings and other processes

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1. Any force that will spin a turbine (e.g. steam from water heated by burning fossil fuels, wind, waves, etc.) 2. Turbine causes generator to produce electricity from electromagnetic induction

1. Coal 2. Oil 3. Natural gas 4. Nuclear 5. Solar 6. Wind 7. Wave 8. Tidal 9. Hydroelectric 10. Geothermal

Renewable – may be replaced as quickly as it is consumed Non-renewable – may not be replaced as quickly as it is consumed

Energy density of a fuel – amount of chemical energy stored per unit mass/volume of a fuel

Greater energy density = greater energy per unit mass/volume = more energy for same mass/volume = more efficient

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Historical -Industrial Revolution had large energy demands -Household appliances and heavy industrial machinery require large amounts of energy Geographical -Fossil fuel reserves abundant in most continents -Industrial developments centered around fossil fuel deposits

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Coal Advantages -simple storage -safe Disadvantages -low energy density Oil Advantages -convenient location of rigs Disadvantages -oil spills and leaks -vulnerable to terrorist activities and natural disasters Natural gas Advantages -high energy density Disadvantages -expensive gas line setup and maintenance costs

Coal - 35% Oil – 38% Natural gas – 45%

Coal Recovery -strip mining (sulfuric acid and soil erosion) -mining hazards (toxic gas and tunnel cave ins) Oil and Natural gas Recovery -extensive time to map and plan construction -expensive construction and maintenance costs -possible spill and leak risks Power Station Use -air pollution (CO₂, CO, SO₂, soot, Nitrogen oxides emissions)