Wind Energy
- Uses wind directly to turn wind turbines, which is connected to the generator
- Energy transfer: kinetic energy → electric energy
Advantages:
- Renewable energy. As long as there is wind produced by the heat energy from the Sun, wind can be produced.
- Relatively low setup cost
- No harmful gases produced
Disadvantages:
- Only able to generate electricity when there is wind.
- Noise pollution
- Aesthetically unpleasant
Water Energy
- Includes energy from waves, tides, and hydroelectric power
- Uses the movement of water to drive electric generators
- Energy transfer: kinetic energy → electric energy
- For hydroelectric power, the gravitational potential energy of water stored up in the dam is transferred to kinetic energy as it rushes down the dam, which is then transferred to electric energy by generators.
Advantage:
- Renewable energy
- No harmful gases produced
- Only suitable in certain locations.
- Tidal barrages may destroy natural habitat.
- Dams require large reservoir, which pushes people and animals away from their homes.
Geothermal Energy
- Hot water and steam stored deep inside the Earth can be used to drive turbines and generators.
- Energy transfer: heat energy → kinetic energy → electric energy
Advantage:
- Renewable energy
- No harmful gases produced
- Can also provide direct heating to drive turbines and generators
- Only suitable for locations with high volcanic activity or thin crusts
Solar Cells
- Directly convert light energy into electrical energy
Advantage:
- Renewable energy
- No harmful gases produced
- Expensive setup cost
- Inefficient energy generation
- Only available on sunny days
Solar Heating Systems
- Use solar panels to absorb thermal radiation from the Sun to heat up water, which produces steam to drive generators
- Energy transfer: heat energy → kinetic energy → electrical energy
Advantage:
- Renewable energy
- No harmful gases produced
- Only available on sunny days
Fossil Fuels
- Burn fossil fuels such as oil, natural, or coal to drive turbine and generator
- Energy transfer: chemical energy → heat energy → kinetic energy → electrical energy
Advantage:
- Relatively cheap
- Easy to obtain
- Non-renewable source. Will eventually be depleted.
- Produces greenhouse gases, which contribute to global warming
- Produces sulfur dioxide, which causes acid rain
Nuclear Energy
- Nuclear fuels, such as uranium or plutonium, undergo chain reaction.
- This reaction produces heat, which heats water to steam, and the steam is drives the turbine and generator.
- Energy transfer: nuclear energy → heat energy → kinetic energy → electrical energy
Advantage:
- Does not produce carbon dioxide or sulfur dioxide
- Very efficient; the same mass of nuclear fuels produces millions of times more energy compared to fossil fuels
- Non-renewable source.
- Potential dangers of large amounts of radioactive material being released in case of accidents
- Nuclear waste remains radioactive for thousands of years, so need to store them safely