Generating Electricity Flashcards
How is electricity generated in a conventional power station?
In most power stations water is heated to produce steam, the steam drives a turbine, which is coupled to an electrical generator that produces the electricity.
How is energy generated in a gas-fired power station?
In some gas-fired power stations, hot gases may drive the turbine directly. A gas-fired turbine may be switched on very quickly.
What is a biofuel?
What sort of power stations can biofuels be used in?
Biofuels are renewable sources of energy
A biofuel is any fuel obtained from living or recently-living organisms.
Some biofuels can be used in small scale gas-fired power stations.
What fuel is used in a nuclear power station?
Uranium
How is electricity generated in a nuclear power station?
The nucleus of a uranium atom can undergo a process called nuclear fission, this process releases energy. There are lots of uranium nuclei, so lots of fission reactions take place, releasing lots of energy. This energy is used to heat water, turning it into steam.
What is a renewable energy source?
Examples?
Sources of energy that cannot be used up.
Energy from wind waves and tides.
How is electricity generated in a wind turbine?
The wind passing over the blades makes them rotate and drive a generator at the top of a narrow tower.
What three forms of water can energy be obtained from?
Falling water
Tides
Waves
How is electricity generated in a hydroelectric power staion?
Water is collected in a reservoir, this water is allowed to flow downhill and turn turbines at the bottom of the hill.
How is surplus electricity used in a pumped storage system?
In a pumped storage system surplus electricity is used at times of low demand to pump the water back up the hill to the top reservoir. This means that the energy is stored. Then at times of high demand the water can be released to fall through the turbines and transfer the stored energy to electrical energy.
How can wave power be used to generate electricity?
We can use the movement of waves on the sea to generate electricity, the movement drives a floating turbine that turns a generator. Then the electricity is delivered to the grid system onshore by a cable.
How can tidal power be used to generate electricity?
The level of the sea around the coastline rises and falls twice each day. These changes in sea level are called tides. If a barrage is built across a river estuary, the water at each high tide can be trapped behind it. When the water is released to fall down to the lower sea level, it drives turbines.
How does solar energy from the sun travel through space to earth?
As electromagnetic radiation
What does a solar cell do and what type of devices can a solar cell power?
A solar cell can transfer the suns energy into electrical energy, each cell only produces a small amount of electricity. So they are useful to power small devices such as watches and calculators.
Large numbers of solar cells are doing together to form what?
Solar panels
Water flowing through a solar heating panel is heated directly by which type of energy?
The suns energy
How does a solar power tower heat water to produce steam?
A solar power tower uses thousands of mirrors to reflect sunlight on the water tank to heat the water and produce steam.
How is geothermal energy produced and how can this be used to turn generators so that electricity is produced?
Geothermal energy is produced inside the Earth by radioactive processes and this heat the surrounding rock. In volcanic or other suitable areas very deep holes are drilled and cold water is pumped down to the hot rocks. There it is heated and comes back to the surface as steam steam is used to drive turbines that turn generators and so electricity is produced.
Name three types of non-renewable energy resources.
Coal, oil, gas and uranium
When will oil and gas most likely run out?
The next 50 years
Name two ways in which scientists are trying to reduce the environmental impact of of using fossil fuels.
What is the abbreviation given to the second method and what does it stand for?
1) Removing sulphur from fuel before burning
2) CCS - carbon capture and storage, involves capturing carbon dioxide before it is released into the atmosphere from power stations and storing it in old oil and gas fields.
How is electricity distributed in Britain?
The National Grid
What is the National Grid?
The National Grid is a network of cables and Transformers that connect power stations to homes, schools, factories and other buildings. Since the whole country is connected to the system power stations can be switched in or out of the grid according to demand.p
Cables in the National Grid are carried long distances across the countryside supported by overhead pylons how are cables different in towns to the countryside cables?
In towns and close to home is the cables are buried underground.
