P3: Energy Resources

Question 1

Where does most of the energy we use come from?

Answer 1

Fossil fuels:
- Coal
- Oil
- Gas

Question 2

How do most power stations work?

Answer 2

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

Question 3

What is used as fuel in nuclear power stations? How does this compare as a source of energy to fossil fuels?

Answer 3

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

Question 4

What happens in a nuclear power station to generate energy?

Answer 4

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

Question 5

Is uranium / plutonium burned in a nuclear power station?

Answer 5

No - the energy is generated via the nuclear process of the atom splitting

Question 6

What are fossil fuels?

Answer 6

Fossil fuels are fuels made from long-dead biological material

This includes plants, animals and other living beings

Question 7

What is a biofuel and what are some examples of this?

Answer 7

Biofuels are fuels that are obtained from living or recently-living organisms

Examples include:
Waste vegetable oil
Methane
Rapeseed plants
Ethanol
Straw
Nutshell
Woodchips

Question 8

Are biofuels renewable?

Answer 8

Yes biofuels are renewable - this is because they can be replaced at the same rate they’re used up

Question 9

Are biofuels carbon neutral?

Answer 9

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

Question 10

What does nuclear fuel mean? what are some examples?

Answer 10

Nuclear fuel - substance used in nuclear reactors that releases energy due to nuclear fission

Question 11

What is a reactor core?

Answer 11

This is the thick steel vessel used to contain fuel rods, control rods and the moderator in a nuclear fission reactor

Question 12

What does renewable mean?

Answer 12

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

Question 13

How do wind turbines generate energy?

Answer 13

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

Question 14

How does a wave generator work to generate energy?

Answer 14

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

Question 15

How does a hydroelectric power station work?

Answer 15

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

Question 16

What is a pumped storage system?

Answer 16

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

Question 17

What happens in a tidal power station?

Answer 17

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

Question 18

Why is wind power not reliable?

Answer 18

Wind doesn’t always blow

Wind speed and direction can be variable

Question 19

How is energy from the sun transferred to the Earth?

Answer 19

Energy from the sun is transferred to earth via electromagnetic radiation

Question 20

What does solar cells do?

Answer 20

They transfer the electromagnetic radiation from the sun into electrical energy

Question 21

What can single solar cells be used to power and why?

Answer 21

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

Question 22

What is a solar panel?

Answer 22

This is when large numbers of solar cells are joined together

Question 23

Where are solar panels useful?

Answer 23

They are useful to generate electricity in remote locations with no access to national electrical grid

Question 24

What happens in solar heating panels?

Answer 24

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

Question 25

What happens in a solar power tower?

Answer 25

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

Question 26

What is geothermal energy?

Answer 26

This is energy that released by radioactive substances deep within the earth near volcanic or other suitable areas

Question 27

What happens in geothermal enery?

Answer 27

The energy released by radioactive substances deep within the Earth heats up surrounding rocks

Question 28

What happens in a geothermal power station?

Answer 28

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

Question 29

What are the disadvantages of fossil fuels?

Answer 29

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

Question 30

How can environmental impact of fossil fuels be reduced?

Answer 30

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

Question 31

When will different fossil fuels run out?

Answer 31

Oil and gases will likely run out in the next 50 years Coal will run out eventually but last longer

Question 32

Which fossil fuels release the most greenhouse gases?

Answer 32

Coal releases the most Then next is oil Then lastly is oil But they all release greenhouse gases

Question 33

What are the advantages and disadvantages of nuclear power?

Answer 33

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

Question 34

What are the advantages and disadvantages of renewable energy sources?

Answer 34

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

Question 35

How do long do different power stations take to start up?

Answer 35

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

Question 36

What is the base load demand?

Answer 36

This is the constant amount of electricity provided by nuclear and coal fired power stations

Question 37

When can the demand for electricity vary?

Answer 37

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

Question 38

How expensive are nuclear power stations?

Answer 38

They are expensive to: Build Run Decomission (stop using)

Question 39

How expensive is carbon capture used to reduce greenhouse gas emissions from fossil fuel power stations?

Answer 39

Carbon capture is very expensive

Question 40

How expensive are renewable energy sources?

Answer 40

Renewable energy sources are expensive to set up and install They are cheap to run

Question 41

When in terms of energy demand is it suitable to use renewable energy sources?

Answer 41

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)

Question 42

What does the cost of a new power station depend on?

Answer 42

It depends on: Building costs Fuel costs Maintenance costs Decomissioning costs