P1- Generating Electricity Flashcards
What are fossil fuels and how are they obtained?
Fossil fuels- such as coal, oil or gas- are obtained from long dead biological material and they will eventually run out.
What is a biofuel and why are they better than fossil fuels?
Give some examples of biofuels.
Biofuels are any fuels obtained from living or recently living organisms.
Biofuels are carbon neutral and renewable sources of energy.
Examples of biofuel include wood, sugar, straw and manure.
How is electricity generated in a nuclear power station?
Uranium or plutonium are used in a nuclear power.
The nucleus’ of the uranium (or plutonium) atom can undergo a nuclear fission. This releases lots of energy which is used to heat water so the steam can turn a turbine connected to a generator which produces electricity.
Compare the use of gas and nuclear to generate electricity.
N- Nuclear energy is a more concentrated source of energy than gas.
N- Nuclear power stations do not produce any greenhouse gases, unlike a gas power station.
G- Gas power stations have a faster start up time than nuclear.
G- Nuclear has a higher decommissioning cost than gas stations.
G- Nuclear produces radioactive waste which is difficult and expensive to get rid of, unlike gas.
Explain some advantages and disadvantages of wind turbines.
A wind turbine uses the energy from the wind to turn the turbines and drive a generator.
A-Wind energy is renewable, produces no polluting waste gases and it is a free energy resource.
D-Wind energy is unreliable, considered an eyesore and noisy and take up lots of space.
Explain some advantages and disadvantages of wave generators.
Wave generators use the movement of waves to generate electricity.
A- Renewable, no fuel cost (free energy resource) and no air pollution.
D- Unreliable, can be hazardous to board and the technology is difficult to develop.
Explain some advantages and disadvantages of hydroelectric power.
HEP is electricity generated using fast flowing water to turn turbines.
A- Very quick start up time, reliable, can generate a lot of energy in mountainous areas, no waste or air pollution.
D- Building dams and flooding valleys changes environment, destructs habitats and homes and dams are expensive to build.
Explain some advantages and disadvantages of tidal power.
Tidal power uses the energy from the tides the drive turbines.
A- Reliable because it doesn’t depend on weather, renewable, no production of polluting gases and it’s a free energy resource.
D- Habitats of birds and animals can be destroyed from building a barrage.
Explain some advantages and disadvantages of solar cells.
Solar cells transfer the sun’s electromagnetic radiation into electrical energy.
A- Renewable, no air pollution or fuel costs, not much maintenance, long life.
D- Only produce small amounts of energy, do not work at night and are unreliable in less sunny countries.
Explain some advantages and disadvantages of solar (heating) panels.
Solar panels directly heat water flowing through them using heat energy from the Sun.
A- Renewable, no air pollution or fuel costs.
D- Unreliable in less sunny countries.
Explain some advantages and disadvantages of geothermal energy.
Geothermal energy is found where the Earth’s crust is thin and the heat is close to the surface. Cold water can be pumped down to the heat, return as steam which can be used to turn turbines.
A- Reliable, renewable, no air pollution or fuel cost.
D- Earthquakes and volcanic action may damage geothermal power stations, drilling is expensive so very few places are economically viable to use geothermal.
How is electricity generated in power stations?
In most power stations, water is heated to produce steam.
The steam drives a turbine which is connected to an electrical generator which produces electricity.
The energy to heat the water can come from burning a fuel.
What does the National Grid do?
The National Grid distributes electricity from power stations to our homes.
What current and voltage is the main electricity in our homes?
Mains electricity is an alternating current.
Mains is at 230V.
What are transformers and why do we use them?
Step-up transformers increase the voltage and step-down transformers decrease the voltage.
Before electricity is transmitted across the National Grid they use step-up transformers because a high grid voltage reduces the energy wasted in the cables.
Step-down transformers are used at local substations before the electricity is sent to homes so it safe to use.
