P1 Generating Electricity

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  • Created by: KAustria
  • Created on: 10-06-14 23:07
How is energy produced in power stations?
Water is heated to produce steam The steam drives a turbine which is coupled with an electrical generator that produces the electricity.
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What are used in fossil-fuel power stations?
Coal, oil and natural gas. Fossil fuels are obtained from long-dead biological material
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How does a gas-fired power station work?
Hot gases may drive the turbine directly. A gas-fired turbine may be switched on quickly.
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What are bio fuels?
fuels that are obtained from living or recently living organisms. Some bio fuels can be used on a small,scale gas-fired power stations. Biofuels are renewable sources of energy.
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What radioactive element is commonly used in a nuclear power station?
Uranium
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How is energy released from a nuclear power station?
The nucleus of a uranium atom can undergo nuclear fission, which releases a lot of energy. There are lots of nuclei so lots of fission reactions take place.
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How is energy used from nuclear fission in a power station?
The energy is used to heat water, turning into steam which drives a turbine.
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What are the advantages and disadvantages of nuclear power stations in comparison to fossil-fuel power stations?
adv : 1. more energy is released per kg of Uranium than per kg of fossil fuel burnt 2. Do not release greenhouse gases Dis: Nuclear power stations produce radioactive waste.
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What is renewable energy?
Sources of energy that can never be used up, unlike fossil fuels or nuclear fuels.
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How does wind produce energy?
1. use to drive turbines directly 2. The wind passing over the blades makes them rotate and drive the generator at the top of the narrow tower.
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Describe hydro electricity power
1.Water is collected in a reservoir 2. The water allowed to flow down hill 3. The movement of the water turns a turbine at the bottom of the hill.
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Describe a pump storage scheme
IN times of low demand surplus electricity is used to pump the water back to the top of the reservoir, which means that the energy is stored.
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What happens when the demand for electricity is high? (hydroelectricity)
The water can be released to fall through the turbines and transfer the stored energy to electrical energy.
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What form of energy is stored in the water in the top of the reservoir of a pumped storage scheme?
Gravitational Potential energy
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Describe Wave Power
We can use the movement of waves on the sea to generate electricity. The movement of the water drives a floating turbine that turns a generator. Then the electricity is delivered to the grid system on shore by a cable.
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Describe tidal power
1. Level of the sea around the coastline rises and falls twice each day (tides) 2. A barrage is built across a river estuary so the high tide can be trapped behind it 3. When the water is released it drives turbines.
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How does solar energy travel form the sun?
It travels through space as electromagnetic radiation.
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What does a solar cell do?
Solar cells transfer solar energy into electrical energy. Each cell produces small amounts of energy, so they are useful to power small devices.
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What is a collection of solar cells called?
A solar panel
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How is water heated by a solar heating panel?
Water flowing through a solar heating panel is heated directly by energy from the sun.
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How does a solar power tower work?
IT uses thousands of mirrors to reflect sunlight into the water tank to heat the water and produce steam.
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What is gerothermal energy?
Energy that has been prodiced inside the Earth by radioactive processes and this heats up the surrounding rock
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How is electricity generated from geothermal rock?
In volcanic or suitable areas.1. Holes are drilled which are very deep. 2. Cold water is pumped down to the hot rocks. 3. The water is heated and returns to the surface as steam 4. The steam is used to drive turbines that turn generators.
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Why are only a few places in the world able to have geothermal power stations?
Because not all areas have geothermal energy near their surface.N
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Name 4 non renewable energy resources
Coal, oil, gas and urnanium
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What are renewable energy resources?
Sources f energy that will not run out and they can be produced as fast as they are used.
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What are the 10 sources of energy?
1. Coal 2. Oil 3. Gas 4. Nuclear 5. Wind 6. Tide 7. Falling water 8. Waves 9. Geothermal 10. Solar
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What is electricity distributed through in the UK?
Through the National Gird
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What is the NAtional Gird?
This is a network of pylons and cabled that connects power stations to consumers.
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How does the National Grid able to act according to demand?
Since the whole country is connected to the system, power station can switched in or out of the grid according to demand.
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How is electricity carried in the country side?
Through over head pylons
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How is electricity carried in towns?
Buried underground.
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What is the NAtional Grid's voltage?
This is 132,000 V or more
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What voltage do power stations produce electricity in?
Voltages at 25000V
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Why do Step-up transformers increase the voltage before it is transmitted across the National Grid?
This is because transmission at hugh voltage reduces the energy wasted in the cables, making the system more efficient.
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Why do step-down transformers reduce the voltage?
Because it would be dangerous to supply electricity to consumers at these very high coltahes.
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What are voltages reduced to in local substations for use at home?
230V
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What is the base load demand?
The constant and supplied amount of electricity that is provided by nuclear, power-fired and oil-fired power stations.
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Why does the demand for electricity vary between summer and winter?
There is a greater demand of electricity in the winter because more people need the electricity for heating.
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How is variable demand of electriicty met?
1. gas-fired power stations 3. Pumped-storage schemes 3. renewable energy resources.
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When demand is low, what is done with electrical energy?
Energy is stored by pumping water to the top of the reservoir of pumped storage schemes.
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What power station has the longest start-up time?
nuclear power stations
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What power station has the shortest start up time?
gas-fired power stations
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Card 2

Front

What are used in fossil-fuel power stations?

Back

Coal, oil and natural gas. Fossil fuels are obtained from long-dead biological material

Card 3

Front

How does a gas-fired power station work?

Back

Preview of the front of card 3

Card 4

Front

What are bio fuels?

Back

Preview of the front of card 4

Card 5

Front

What radioactive element is commonly used in a nuclear power station?

Back

Preview of the front of card 5
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