P8.2 - Powering Earth Flashcards
What are the differences between renewable and non-renewable energy?
Renewable energy can be produced and supplied at the rate it is being used and hence will not run out. However, non renewable sources of energy will eventually run out as they take a very long time to form and cannot be supplied at the rate they are being used up in.
Renewable energy sources such as solar and geothermal generate greenhouse gases do not generate greenhouse gases nor nuclear radiation.
Therefore, renewable energy sources donโt give rise to environmental problems such as global warming.
However, unlike non-renewable sources of energy, renewable sources of energy such as solar and wind, are unreliable.
How do fossil fuel power plants work?
You burn fossil fuels such as coal, oil and gas.
The energy released heats water to make steam.
The steam turns a turbine.
The turbine turns a generator and electricity is produced.
What is the difference between nuclear power plants and conventional power plants?
The heat required to turn the water to steam comes from nuclear fission reactions and not burning fossil fuels.
What are the advantages and disadvantages of fossil fuels power plants?
Advantages
- Cost effective
- Reliable source of energy
Disadvantages
- The burning of fossil fuels releases greenhouses gases
- Fossil fuels are non-renewable
What are the advantages and disadvantages of nuclear power plants?
Advantages
- Lots of energy per kg than fossil fuels
- No greenhouse gases produced
Disadvantages
- Radioactive waste is difficult to dispose of
- It is potentially very dangerous
What are biofuels?
Biofuels are fuels that are obtained from living (or recently living) organisms.
How are biofuels carbon neutral?
Biofuels are carbon neutral because the carbon dioxide released in burning biofuels is reabsorbed when a new crop of plants is grown.
This ensures that there is no net increase in the amount of carbon dioxide in the atmosphere.
What are the two different types of โsolar panelsโ?
Solar panels - Light energy to heat energy Solar cells (photovoltaic cells) - Light energy to electrical energy
What energy sources are used for heating?
- Fossil fuels
- Biofuels
- The sun
- Water pumped into hot rock
What energy sources are used for transportation?
- Fossil fuels
- Biofuels
What energy sources are used for generating energy?
- Fossil fuels
- Biofuels
- Nuclear fuel
- Solar power
- Tidal power
- Wind power
- Wave power
- Geothermal power
- Hydroelectric power
Why has our use of energy sources changed over time?
There has been an increase in:
- Population
- The use of devices that use fuels
- Energy generation
What do individuals or governments need to consider when deciding which energy sources to use?
Cost (to set up, and to remove)
Effect on the environment (pollution, how it looks if you live nearby)
Contribution to climate change.
How long the sources will last.
What is The National Grid?
The National Grid is a network of cables and pylons, that transfer electrical energy generated in power plants to homes and businesses.
Why are transformers used in the national grid?
The electricity has to be transferred over long distances. This electrical power can be subject to a lot of loss as heat, if the current is high.
Transformers are used to adjust the voltage (therefore the current) to minimise power/energy lost as heat.