P3 - Sustainable Energy Flashcards
What type of energy source is electricity?
A secondary energy source
How can electricity be generated?
From another energy source, e.g. coal, nuclear power etc
Why is electricity a secondary energy source?
It is generated from energy of another source, e.g. coal, nuclear power etc
Why is electricity a useful energy source?
It can be easily transmitted over long distances and used in many ways.
What are the main primary energy sources that humans use?
- Fossil fuels
- Nuclear fuels
- Biofuel
- Wind
- Waves
- Radiation from the Sun
Give 3 examples of fossil fuels.
- Oil
- Coal
- Gas
Give an example of a biofuel.
Wood
To generate electricity, fuel is burned to produce what?
Heat
To generate electricity, fuel is burned to produce heat. Explain what happens next in the generation of heat.
- The heat is used to boil water into steam
- Steam drives turbines that power generators
- Generators produce electricity sent to a step-up transformer and then to National Grid
- Electricity is then distributed to homes and business from here at high voltages to reduce energy losses
- The high voltages are stepped down by a transformed to the mains supply voltage in our homes of 230V
Why is electricity distributed to homes and businesses at a high voltage?
To reduce energy losses
When high voltages of electricity are stepped down by a transformer as it reaches the mains supply voltage in homes, what is the voltage it is stepped down to?
230V
Power stations that burn fossil fuels (like coal) produce a greenhouse gas. Which gas?
Carbon Dioxide
Power stations that burns fossil fuels produce carbon dioxide, a greenhouse gas. What is the problem with this?
It contributes to global warming and climate change.
Nuclear power stations release energy owing to changes in what?
The nucleus of radioactive substances
Nuclear power stations release energy owing to changes in what part of radioactive substances?
The nucleus
Nuclear power stations release energy owing to changes in the nucleus of what?
Radioactive substances
Nuclear power stations release energy owing to changes in the nucleus of radioactive substances.
a) What is not produced?
b) What is produced?
a) Carbon Dioxide
b) Radioactive waste
What is irradiation?
When nuclear waste emits ionising radiation. When handling radioactive
What would it be called if any part of a radiation source was to get on your clothes or enter your body?
You would become contaminated
What would being contaminated mean?
You would continually be exposed to dangerous ionising radiation and it would be more of a threat to your health than from a short period of irradiation from a radioactive source.
It would cause damage to living cells, eventually leading to cancer or cell death.
At which stages in the process of electricity generation can energy be lost?
At every stage
What can be used to show the generation and distribution of electricity and the efficiency of energy transfers?
Sankey diagrams
What can Sankey diagrams be used for?
To show the generation and distribution of electricity and the efficiency of energy transfers
What do Sankey diagrams show?
That from the energy put into the power station, almost half is lost to the surroundings (mostly as heat) before the electricity even reaches home. Further energy is lost during energy transfers in the home when the electricity is used.
________ energy supplies are running out, and both ___________ and fossil fuels cause __________ damage.
- Conventional
- Nuclear
- Environmental
The burning of fossil fuels releases carbon dioxide into the atmosphere, contributing to global warming and climate change. What does this mean?
That alternative energy sources are becoming more important
a) Give some alternative ways to generate electricity (other than nuclear and fossil fuels).
b) Are these renewable? What does this make them?
a) - Wind
- Waves
- Hydroelectric power
- Biofuel (.e.g wood)
- Solar power
- Geothermal
b) These renewable energy sources are primary energy sources and will not run out like fossil fuels
What are wind turbines an example of?
A renewable energy source
Briefly describe how wind turbines work.
The force of wind turns blades of the wind turbine, which provides power to a generator.
Is the amount of electricity produced from wind turbines small or large?
Small
The amount of electricity produced by wind turbines is small, which means what?
It would need hundreds of turbines to replace a conventional power station.
Once a wind turbine is built, how expensive is it to keep running?
Once they are build they provide free energy as long as the wind is blowing.
What are hydroelectric dams an example of?
Renewable energy sources
Explain briefly how hydroelectric dams work.
Water stored in the reservoir flows down pipes and turns the turbines. This powers the generators and produces electricity.
a) How much land would it take to build a hydroelectic dam?
b) What about the energy produced once built?
a) Large areas of land
b) They provide large amounts of reliable, fairly cheap energy
What is a generator used for?
To produce electricity when a magnet is made to rotate near a coil.
In larger generators, what kind of magnet is used?
An electromagnet
What other energy sources can be used to drive a generator?
Burning fossil fuels; wind turbine; water turbine
Explain how burning fossil fuels can be used to drive a generator.
It can be used to heat water and produce steam to drive a turbine and generator.
Complete the sentence:
The greater the current supplied by a generator…
…the more primary fuel it uses each second.
State the 3 stages in the process of the use of a generator in a hydroelectric power station.
- Water in the reservoir has potential energy
- Flowing water has kinetic energy
- Magnet rotates near to the coil in the generator. This changes kinetic energy into electrical energy
What does the following process show?
- Water in the reservoir has potential energy
- Flowing water has kinetic energy
- Magnet rotates near to the coil in the generator. This changes kinetic energy into electrical energy
The energy changes in a hydroelectric power station when a generator is driven directly by the flow of water through a series of turbine blanes.
Why is electricity distributed through the National Grid at high voltage?
To reduce the energy losses
Name 5 primary energy sources used to generate electricity.
Coal; gas; oil; nuclear; wind; water (hydroelectric, tidal, wave); solar; biofuel
The burning of fossil fuels releases carbon dioxide into the atmosphere. What 2 problems does this contribute to?
Global warming; climate change
How is a voltage induced between the ends of a coil?
By rotating a magnet near the coil
What are the 3 forms of energy that are involved in a hydroelectric power station?
Potential energy; kinetic energy; electrical energy
In a hydroelectric power station, what energy does the generator convert from and into?
From kinetic energy into electrical energy
In a hydroelectric power station, the generator converts kinetic energy into electrical energy. What then happens to this electrical energy?
It can be transferred to homes and factories via. the National Grid
What happens when charge flows through a component?
Energy is transferred to the component and lost to the environment.
What is power a measure of?
The rate of energy transfer
How is power measured?
In watts (W)
Give the formula used to calculate power.
power = voltage x current
An electric motor works at a current of 3A and a potential difference of 24V. What is the power of the motor?
Power = potential difference x current Power = 24V x 3A Power = 72W
How can potential difference be calculated? (HT)
By rearranging the power formula as so:
potential difference = power / current
A 40W lamp works at a current of 0.18A. What is the potential difference? (HT)
Potential difference = power / current
= 40W / 0.18A
= 222V
How is energy measured?
In joules
What is a joule?
A very small amount of energy
What does a domestic energy meter measure?
The energy transfer in kilowatt hours
How is the energy transfer in kilowatt hours measured?
By a domestic energy meter
Give the fomula by which energy transfer in joules and kilowatt hours can be calculated.
energy transferred = power x time
A 30W lightbulb is switched on for 45 seconds. What is the energy transferred in joules/
Energy transferred = power x time
= 30W x 45secs.
= 1350J
A 2000W electric hot plate is swtiched on for 90 minutes. What is the energy transferred in kWh?
Energy transferred = 2kW x 1.5h
= 3kWh
How can you work out the power or time? (HT)
By rearranging the energy transfer formula as follows:
Power = energy transferred / time
What is power? (HT)
The rate at which an appliance or device transfers energy.
A hairdryer is switched on for 6 minutes and the total energy transferred is 0.2kWh. What is the power rating of the hairdryer? (HT)
Power = energy transferred / time
= 0.2kWh / 0.1h
= 2kW
If you know the power, time and cost per kilowatt hour, what can be calculated?
The cost of the electrical energy used.
Give the formula used to calculate the cost of electrical energy used.
total cost = number of units (kWh) x cost per unit
A 2000W electric fire is switched on for 30 minutes. How much does it cost if electricity is 8p per unit (kWh)?
Energy transferred = 2kW x 0.5h
= 1kWh (or 1 unit)
Cost = 1 x 8p
= 8p
Complete the sentence:
The greater the proportion of energy that’s usefully transferred…
…the more efficient the appliance is.
How can you tell that an appliance is efficient?
The proportion of energy that is usefully transferred is large
How can efficiency be calculated?
efficiency (%) = energy usefully transferred / total energy supplied x 100
Calculate the efficiency for a lightbulb:
- Energy in = 100J
- Useful energy out = light as 20J
20 / 100 x 100% = 20%
Calculate the efficiency for a kettle:
- Energy in = 2000J
- Useful energy out = heat (in water) as 1800J
1800 / 2000 x 100% = 90%
Calculate the efficiency for an electric monitor:
- Energy in = 500J
- Useful energy out = kinetic as 300J
300 / 500 x 100% = 60%
Calculate the efficiency for a television:
- Energy in = 200J
- Useful energy out = light of 20J and sound of 30J
50 / 200 x 1000% = 25%
Is the demand for energy continually increasing or decreasing?
Increasing
What issues are raised by the continually increasing demand for energy?
About the availability of energy sources and the environmental effects of them
True or False?
There are advantages and disadvantages to consider when using any primary energy source to generate electricity.
True
When comparing energy sources for generating electricity, the factors used to asses which source is the most favourable are _____, _______ and ___________ ___________.
- Efficiency
- Cost
- Environmental damage
____________ ________ and __________ (how long a source lasts for) can also be assessed when comparing energy sources. (HT)
- Power output
- Lifetime
Give the advantages of using fossil fuels.
- High energy output
- Easily distributed
- Readily available
- Can be used anywhere
- Efficient
- Convenient
Using the following advantages, name the energy source being described.
- High energy output
- Easily distributed
- Readily available
- Can be used anywhere
- Efficient
- Convenient
Fossil fuels.
Give the disadvantages of using fossil fuels.
- Non renewable
- Burning generates greenhouse gases
- Obtaining fuels damages the environment
- Contributes to acid rain
- Emissions from the transport of fuel
Using the following disadvantages, name the energy source being described.
- Non renewable
- Burning generates greenhouse gases
- Obtaining fuels damages the environment
- Contributes to acid rain
- Emissions from the transport of fuel
Fossil fuels
Is the set-up cost of using fossil fuels as an energy source high or low?
High
Is the power output of using fossil fuels as an energy source high or low? (HT)
High
Give the advantages of using nuclear energy.
- Reliable
- No greenhouse gases
- Convenient
- Efficient
- Convenient
Using the following advantages, name the energy source being described.
- Reliable
- No greenhouse gases
- Convenient
- Efficient
- Convenient
Nuclear
Give the disadvantages of using nuclear energy.
- Disposal of nuclear waste is difficult and needs specialist handling
- It’s expensive to remove spent fuel and send it for processing
- Threat of damage to the environment
Using the following disadvantages, name the energy source being described.
- Disposal of nuclear waste is difficult and needs specialist handling
- It’s expensive to remove spent fuel and send it for processing
- Threat of damage to the environment
Nuclear
Is the set-up cost of using nuclear energy as an energy source high or low?
Very high
Is the power output of using nuclear as an energy source high or low? (HT)
High
Give the advantages of using biofuel as an energy source.
- Renewable
- Inexhaustible supply
Using the following advantages, name the energy source being described.
- Renewable
- Inexhaustible supply
Biofuel
Give the disadvantages of using biofuel as an energy source.
- Needs a large area of land to produce
- Burning leads to greenhouse gases
- Expensive to produce (labour, machinery)
Using the following disadvantages, name the energy source being described:
- Needs a large area of land to produce
- Burning leads to greenhouse gases
- Expensive to produce (labour, machinery)
Biofuel
Is the set-up cost of using biofuel as an energy source high or low?
Medium
Is the power output of using biofuel as an energy source high or low? (HT)
Medium
Give the advantages of using solar energy.
- Renewable
- No greenhouse gases
- No solid or liquid waste
Using the following advantages, name the energy source being described.
- Renewable
- No greenhouse gases
- No solid or liquid waste
Solar energy
Give the disadvantage of using solar energy.
- Expensive and inefficient
- Needs a large surface area for panels
- Intensity of solar energy isn’t consistent
Using the following disadvantages, name the energy source being described.
- Expensive and inefficient
- Needs a large surface area for panels
- Intensity of solar energy isn’t consistent
Solar energy
Is the set-up cost of using solar energy as an energy source high or low?
High
Is the power output of using solar energy as an energy source high or low? (HT)
Low
Give the advantages of using wind energy.
- Renewable
- No greenhouse gases
- No solid or liquid waste
Using the following advantages, name the energy source being described.
- Renewable
- No greenhouse gases
- No solid or liquid waste
Wind energy
Give the disadvantages of using wind energy.
- Expensive
- Noise and spoils the view
- Needs a large surface area for panels
- Intensity of solar energy isn’t consistent
Using the following disadvantages, name the energy source being described.
- Expensive
- Noise and spoils the view
- Needs a large surface area for panels
- Intensity of solar energy isn’t consistent
Wind energy
Is the set-up cost of using wind energy as an energy source high or low?
High
Is the power output of using wind energy as an energy source high or low? (HT)
Low
Give the advantages of using water energy (waves, hydroelectricity, tidal).
- Renewable
- Reliable
- No greenhouse gases
Using the following advantages, name the energy source being described.
- Renewable
- Reliable
- No greenhouse gases
Water energy (waves, hydroelectricity, tidal)
Give the disadvantages of using water energy (waves, hydroelectricity, tidal).
- Expensive
- Environmental damage to the location
- Limited locations available
- Changes the ecosystem through flooding
Using the following disadvantages, name the energy source being described.
- Expensive
- Environmental damage to the location
- Limited locations available
- Changes the ecosystem through flooding
Water energy
Is the set-up cost of using water energy as an energy source high or low?
High
Is the power output of using water energy as an energy source high or low? (HT)
High
Give the advantages of using geothermal energy.
- Renewable
- Small emission of greenhouse gases
Using the following advantages, name the energy source being described.
- Renewable
- Small emission of greenhouse gases
Geothermal energy
Give the disadvantages of using geothermal energy.
- Expensive to drill for suitable sites
- Limited locations
Using the following disadvantages, name the energy source being described.
- Expensive to drill for suitable sites
- Limited locations
Geothermal energy
Is the set-up cost of using geothermal energy as an energy source high or low?
High
Is the power output of using geothermal energy as an energy source high or low? (HT)
Medium
What can save on energy consumption? (2 things)
- energy losses need to be reduced
- the percentage of useful energy obtained from a source needs to be increased
Give the ways by which energy losses in the home can be reduced. (6 things)
- Installing double or triple glazed windows
- Cutting out draughts around doors, windows and skirting boards
- Installing at least 270mm of loft insulation
- Using energy sacing light bulbs
- Switching off appliances (i.e. not leaving them on standby) when not required
- Replacing old appliances with more efficient, newer models
Explain the ways in national context that energy can be saved. (5 things)
- Replacing old houses with new efficient ones
- Increased use of public transport
- More efficient trains and buses
- Encourage more widespread recycling
- Encourage car sharing and fewer journeys
Explain the ways in a workplace context that energy can be saved. (5 things)
- Cleaning air conditioner filters (can save 5% of the energy used in running the system)
- Using low energy light bulbs
- Roof insulation/cavity wall insulation in modern buildings
- Use of efficient, modern, low energy machinery
- Use of modern, efficient vehicles for transport of goods
Explain the ways in a home context that energy can be saved. (5 things)
- Modern efficient appliances
- Double glazing
- Loft insulation
- Cavity wall insulation
- Draught proof rooms
By how much can modern efficient appliances save per year?
£190
By how much can double glazing save per year?
£130
By how much can loft insulation save per year?
£145
By how much can cavity wall insulation save per year?
£110
By how much can draught proof rooms save per year?
£25
To ensure a security of electricity supply nationally, what is needed? (HT)
A mix of energy sources
a) By 2015, how much is Britain expected to import of the gas it needs? (HT)
b) What can this be compared to? (HT)
a) 80%
b) 40% in 2011
Why is relying on primary energy sources a concern? (HT)
There are political and expense issues to consider
Give some issues to consider (political and expense) when relying on primary energy sources. (HT)
- Many nuclear power stations are coming to an end of their useful lives and will soon need to be replaced
- There are also restrictions on many coal-fired plants because of tough new European emissions standard
How much energy is transferred by a 60W lamp in 3 seconds?
180J
How efficient is an electric motor that uses 400J/s to give 100J/s of useful energy?
25%
An electric fire was left on for 30 minutes and the total energy transferred was 1.5kWh. What is the power rating of the fire? (HT)
3kW