Topic 8.2: World Energy Sources Flashcards
8.2.1: Identify different world energy sources (8)
oil, natural gas, coal, nuclear, hydroelectric, photovoltaic cells, biofuel, geothermal
8.2.2: Outline and distinguish between renewable and non-renewable energy sources
Non-renewable sources are finite sources, which are being depleted, and will run out. They include fossil fuels (oil, natural gas and coal), and nuclear fuels (uranium). The energy stored in these sources is, in general, a form of potential energy, which can be released by human action.
Renewable sources include solar energy, other forms indirectly dependent on solar energy (wind and wave energy) and tidal energy
8.2.3: Define the energy density of a fuel
Energy density is the energy that can be obtained from a unit mass of the fuel.
What is energy density measured in?
Energy density is measured in J kg-1
8.2.4: Discuss how choice of fuel is influenced by its energy density (3)
Transport costs
Storage
Application
8.2.4: Discuss how choice of fuel is influenced by its energy density (3)
Transport costs
Storage
Application
What is the percent of total energy produced for oil?
40%
What is the percent of total energy produced for natural gas?
23%
What is the percent of total energy produced for coal?
23%
What is the percent of total energy produced for nuclear?
7%
What is the percent of total energy produced for hydroelectric?
7%
What are the advantages of fossil fuels? (4)
Relatively cheap (while they last)
• High power output (high energy density)
• Variety of engines and devices use them directly and easily
• Extensive distribution network is in place
What are the disadvantages of fossil fuels? (5)
- Will run out
- Pollute the environment
- Contribute to greenhouse effect by releasing greenhouse gases into atmosphere
- High cost of distribution due to high mass and volume of materials and high cost of storing (needs extensive storage facilities)
- Pose serious environmental problems due to leakages at various points along the production
What are the advantages of nuclear energy? (3)
- High power output
- Large reserves of nuclear fuels
- Nuclear power stations do not produce greenhouse gases
What are the disadvantages of nuclear energy? (4)
- Radioactive waste products difficult to dispose of
- Major public health hazard should ‘something go wrong’
- Problems associated with uranium mining
- Possibility of producing materials for nuclear weapons
What are the advantages of solar power/photovoltaic cells? (3)
- “Free”
- Inexhaustible
- Clean
What are the disadvantages of solar power/photovoltaic cells? (5)
- Works during the day only
- Affected by cloudy weather
- Low power output
- Requires large areas
- Initial cost high
What are the advantages of hydroelectric power? (3)
- “Free”
- Inexhaustible
- Clean
What are the disadvantages of hydroelectric power? (3)
- Very dependent on location
- Requires drastic changes to environment
- Initial costs high
What are the advantages of wind power? (4)
- “Free”
- Inexhaustible
- Clean
- Ideal for remote island locations
What are the disadvantages of wind power? (5)
- Works only if there is wind – not dependable
- Low power output
- Aesthetically unpleasant (and noisy)
- Best locations far from large cities
- Maintenance costs high
What are the advantages of wave power? (4)
- “Free”
- Inexhaustible
- Clean
- Reasonable energy density
What are the disadvantages of wave power? (6)
- Works only in areas with large waves
- Irregular wave patterns make it difficult to achieve reasonable efficiency
- Difficult to couple low-frequency water waves with high-frequency turbine motion
- Maintenance and installation costs high
- Transporting the produced power to consumers involve high costs
- Devices must be able to withstand hurricane and gale-force storms.
