P3: Energy Resources Flashcards
Where does most of the energy we use come from?
Fossil fuels:
- Coal
- Oil
- Gas
How do most power stations work?
Water is heated to produce steam
The steam drives a turbine
The turbine is connected to an electrical generator which generates electricity as the turbine spins
What is used as fuel in nuclear power stations? How does this compare as a source of energy to fossil fuels?
Nuclear power stations use URANIUM or PLUTONIUM as fuel
MUCH MORE energy is released per kilogram of uranium or plutonium when compared to fossil fuels
What happens in a nuclear power station to generate energy?
Uranium (and plutonium) atoms have nucleus’ which are very unstable and can split into two and release lots of energy
There are lots of uranium (or plutonium) nuclei in the reactor core so lots of energy can be released
This energy heats water and turns it into steam which then turns turbines generating electricity using the generator
Is uranium / plutonium burned in a nuclear power station?
No - the energy is generated via the nuclear process of the atom splitting
What are fossil fuels?
Fossil fuels are fuels made from long-dead biological material
This includes plants, animals and other living beings
What is a biofuel and what are some examples of this?
Biofuels are fuels that are obtained from living or recently-living organisms
Examples include:
Waste vegetable oil
Methane
Rapeseed plants
Ethanol
Straw
Nutshell
Woodchips
Are biofuels renewable?
Yes biofuels are renewable - this is because they can be replaced at the same rate they’re used up
Are biofuels carbon neutral?
Yes biofuels are carbon neutral as the living organism they are made from take in as much CO2 as they release when the fuel is
burnt3
What does nuclear fuel mean? what are some examples?
Nuclear fuel - substance used in nuclear reactors that releases energy due to nuclear fission
What is a reactor core?
This is the thick steel vessel used to contain fuel rods, control rods and the moderator in a nuclear fission reactor
What does renewable mean?
This describes energy from a natural source that is being replenished at the same rate it is being used up or faster so it cannot run out
How do wind turbines generate energy?
The wind passing over the turbine blades at the top of a tall tower
This makes the turbine rotate and drives a generator to generate electricity
How does a wave generator work to generate energy?
The movement of waves on the sea can drive a floating turbine
This causes the turbine to rotate and turns a generator to generate electricity
The electricity is delivered to the grid system onshore by a cable
How does a hydroelectric power station work?
Water is collected in a reservoir at the top of a hill
Water then is allowed to flow back downhill
As it moves downhill it turns a turbine that is connected to a generator that this generates electricity at the bottom of the hill
What is a pumped storage system?
This is a type of hydroelectric station where the water collected at the bottom of the hill can be pumped back to the top
When there is a greater demand for energy this water that has been pumped up to the top can be released from the top and move downhill to generate electricity by turning the turbines again
What happens in a tidal power station?
Water from each high tide is trapped behind a barrage
The water is then released back into the sea through turbines
As water passes through the turbines it turns them and drives a generator to make electricity
Why is wind power not reliable?
Wind doesn’t always blow
Wind speed and direction can be variable
How is energy from the sun transferred to the Earth?
Energy from the sun is transferred to earth via electromagnetic radiation
What does solar cells do?
They transfer the electromagnetic radiation from the sun into electrical energy
What can single solar cells be used to power and why?
Single solar cells can power small devices like calculators and watches
This is because a single solar cell only produces a small amount of electricity
What is a solar panel?
This is when large numbers of solar cells are joined together
Where are solar panels useful?
They are useful to generate electricity in remote locations with no access to national electrical grid
What happens in solar heating panels?
Solar heating panels have pipes of water running through them
They directly use the sun’s energy to heat the water as it flows through them
What happens in a solar power tower?
A solar power tower uses thousands of mirrors to reflect sunlight onto water tank that heats the water and makes steam
This steam then drives generators and generates electricity
What is geothermal energy?
This is energy that released by radioactive substances deep within the earth near volcanic or other suitable areas
What happens in geothermal enery?
The energy released by radioactive substances deep within the Earth heats up surrounding rocks
What happens in a geothermal power station?
Very deep holes are drilled and cold water is pumped down to cool down the hot rocks heated by radiactive energy release
The cold water is heated by the rocks and turns into the steam
This steam comes back up and drives turbines attached to a generator to make electricity
What are the disadvantages of fossil fuels?
They are NON-RENEWABLE - they will eventually run out
When they are burnt they release GREENHOUSE GASES such as CO2 which contributes to global warming
Burning coal and oil releases sulfur which leads to ACID RAIN
How can environmental impact of fossil fuels be reduced?
Capturing and storing CO2 in old oil and gas fields -> reduces greenhouse gas emissions
Removing sulfur from coal / oil before burning them -> reduces risk of acid rain
When will different fossil fuels run out?
Oil and gases will likely run out in the next 50 years
Coal will run out eventually but last longer
Which fossil fuels release the most greenhouse gases?
Coal releases the most
Then next is oil
Then lastly is oil
But they all release greenhouse gases
What are the advantages and disadvantages of nuclear power?
Advantages:
-> Do not release greenhouse gases
-> Generates much more energy per kilogram than fossil fuels
Disadvantages:
-> Used fuel rods have radioactive waste that needs to be stored safely for centuries
-> Although nuclear stations are generally safe - an accident can make the surrounding area unsafe for many years
What are the advantages and disadvantages of renewable energy sources?
Advantages:
-> Renewable - won’t run out and can be made as quickly as they are used
-> Do not produce greenhouse gases or other dangerous waste
-> Can be used in places where connection the grid isn’t economical
Disadvantages:
-> Currently they are unable to meet the world’s demand for electricity
-> Most renewables aren’t available all the time / can be unreliable
-> Wind, tidal, hydroelectric can be an eyesore and affect plant / animal life
-> Solar cells need to cover large areas to generate large amounts of power
How do long do different power stations take to start up?
Gas power stations can start up the quickest
Oil is the next quickest, followed by coal
Nuclear is the slowest power station to start up
What is the base load demand?
This is the constant amount of electricity provided by nuclear and coal fired power stations
When can the demand for electricity vary?
During different times of the day - Morning and evenings more as people are back at home from school / work
During different times of the year - More energy used in winter as people spend more time at home and use energy to heat up their homes
How expensive are nuclear power stations?
They are expensive to:
Build
Run
Decomission (stop using)
How expensive is carbon capture used to reduce greenhouse gas emissions from fossil fuel power stations?
Carbon capture is very expensive
How expensive are renewable energy sources?
Renewable energy sources are expensive to set up and install
They are cheap to run
When in terms of energy demand is it suitable to use renewable energy sources?
Can be used when demand is high (lots of people using energy)
AND
The conditions are suitable (eg windy for turbines, sunny for solar etc)
What does the cost of a new power station depend on?
It depends on:
Building costs
Fuel costs
Maintenance costs
Decomissioning costs
