1. Energy for the future
Electricity Generation - Part 2

2. Generators Use energy to generate electric currents.
A moving magnet pushes the electrons along a wire.
The energy used to move the magnet is carried by the electric current.
magnet
Coil of wire
torch bulb

3. The inventor of the generator
Michael Faraday
invented the generator in 1831.

4. energy What do we need to make a generator for a power station?
Strong magnets
Lots of wire
then lots of
energy
to turn the generator.

5. Factories, homes and schools need huge amounts of energy
Generators in
power stations supply
electricity to factories,
homes and schools.
These generators are
in power stations
and are huge!

6. Generators in power stations are very, very big
Huge generators need huge amounts of energy.
The energy turns the generators.
The electric current carries the energy to where it is needed.
Size of a person

7. How can a generator be turned?
Steam can be used to turn a turbine to turn the generator.
Turbine
Source of steam

8. A power station
electric current

9. How can water be heated to make steam?
The smoke is dirty and pollutes the atmosphere.
Also produces lots of carbon
dioxide which is a green house gas –
heats up the Earth.
Old way:
Burn coal
Newer way:
Burn gas
Gas is cleaner than coal but still makes lots of carbon dioxide
Eventually the world will run out of coal and gas.

10. Steam from nuclear energy
Nuclear reactors can be used
- to split atoms
- to release energy
- to boil water
– to make steam
- to turn the generators. +
splits to give
This does not cause pollution
but some waste is very dangerous and has to be handled very carefully.

11. Steam from the Earth It is hot inside the Earth
70000 C
5000 C
- giving energy to generate electricity.
In some countries there are hot rocks close to the surface of the Earth.

12. Energy from the Earth
In some countries energy from the Earth can be used
to boil water
to turn generators.
This does not cause pollution
and will not run out.
NREL geo pacific gas and electric
But is not an option in the UK !
It would need very very deep holes!

13. Electricity from waste
Vegetation and animal dung give off energy as they rot. This can be used to heat homes and greenhouses directly.
Also waste can be burned
- to boil water
- to make steam
- to turn generators.
The process uses up waste.
But produces carbon dioxide.

14. How else can we turn a generator without polluting the Earth?
Use flowing water.
top of dam
Hoover Dam in USA – 220m high

15. Hydroelectricity Running water turns the generator
Water from a mountain lake
(Tennessee Valley Authority)
Does not pollute the atmosphere.
The dam must be high in mountains.

16. Waves Energy from waves can be used to turn generators.
We have lots of waves in the seas around the UK.
Does not cause pollution.
There are more problems to solve.

17. We can make a windmill When you blow the windmill it turns.
The moving air pushes the blades round.
What happens if you blow harder?

18. Wind can turn generators
Many years ago
windmills were used to turn
mill stones to grind grain.
Now modern wind turbines are used to turn generators.
Do not pollute the air.
Wind is not used up.
But sometimes the wind does not blow.

19. Energy from the Sun
NASA

20. Solar cells
Use solar cells to change the energy in sunlight into electricity
– no generator needed
- needs lots of sunlight.
Solar cells
traffic sign
parking meter

21. The space station has huge solar panels
The International Space Station uses solar panels to collect energy, making it possible for scientists to live on board and do experiments.
NASA
The framework is 109 metres long.

22. + Fusion Makes the Sun shine.
Scientists are finding ways to get huge amounts of energy.
when small atoms join together,
energy is given out
– like in the Sun.
Will not run out.
Does not pollute the air.
The future? Not possible for another 20 years! +
gives

23. Energy Sources: Fossil fuels Renewable sources – do not run out
Coal - pollution
Gas - pollution
Oil pollution
Renewable sources – do not run out
Hydroelectricity – needs mountains
Wind - only works when wind blowing
Waste & rotting vegetation – greenhouse gases
Sunlight – best in sunny countries
Geothermal – only in countries with hot springs
Waves – small scale only – so far
Energy from nuclear reactions
Fission – waste needs very careful handling
Fusion – waste less dangerous
will not run out - but very difficult !

24. You will have to choose ! Re-cap
A generator generates an electric current
by moving magnets near a coil of wire.
We need a source of energy to turn the
generator:
Burn fossil fuels?
Nuclear reactions?
Renewable energy?
You will have to choose !