1. Renewable and non-renewable energy sources

3. Renewable and non-renewable energy sources
A renewable energy resource is one that will not run out.
Renewable energy sources do not produce radioactive waste, greenhouse gases or acid rain.
Fossil fuels such as coal. gas and oil as well as uranium are non-renewable energy sources.

4. Hydroelectric power
Falling water is used to drive a turbine which rotates an electrical generator.
Energy changes:
gravitational potential
to kinetic
to electrical

5. Hydroelectric power station

6. Very limited locations Wildlife affected Expensive to build
ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
Short start up time
DISADVANTAGES
Very limited locations
Wildlife affected
Expensive to build
The Hoover Dam near Las Vegas

7. Wave power Waves can be used to drive an electrical generator.
Energy changes:
kinetic
to electrical

8. ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
No land needed
Short start up time
DISADVANTAGES
Unreliable
Can only be used in areas with suitable waves
Prone to storm damage
Many needed to produce the same energy of a small thermal power station
Danger to shipping

9. Tidal power
Tidal power station at La Rance, Brittany
Moving water caused by the tides is used to drive a turbine directly which rotates an electrical generator.
Energy changes:
gravitational potential
to kinetic
to electrical

10. Tidal power station

11. Very limited locations Wildlife affected Expensive to build
ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
Short start up time
DISADVANTAGES
Very limited locations
Wildlife affected
Expensive to build
Proposed Severn Estuary Tidal Power Scheme

12. Wind power
Wind is used to rotate a turbine (the blades) which turns an electrical generator.
A wind farm
Energy changes:
kinetic
to electrical

13. ADVANTAGES
Renewable energy source
No greenhouse gases
No acid rain
No radioactive waste
Inexpensive to build
Short start up time
DISADVANTAGES
Unreliable – needs wind!
Best used in places where they will often be regarded as unsightly
Many turbines are needed to produce the same energy of a small thermal power station
Noise (possible)
Danger to wildlife

14. Geothermal energy
In some volcanic areas hot water and steam rise to the surface. The steam can be tapped and used to drive turbines. This is known as geothermal energy.
Energy changes:
thermal (heat)
to kinetic
to electrical

15. ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
Short start up time
DISADVANTAGES
Very limited locations
Expensive to build

16. Solar heating
Heat energy from the Sun is focussed onto pipes containing water.
The water boils producing steam.
The steam is used to drive turbines which turn electrical generators.
Energy changes:
thermal
to kinetic
to electrical

17. ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
DISADVANTAGES
Sunshine needed and so best in desert regions
Can only be used during the day
A large amount of land is needed to produce a significant amount of energy

18. Solar cells Electricity produced directly from the Sun’s radiation.
Energy changes:
light
to electrical

19. ADVANTAGES
Renewable
No greenhouse gases
No acid rain
No radioactive waste
Instant start up time
DISADVANTAGES
Unreliable – sunshine is needed for solar cells
Day time use only
Only 10% of solar energy is converted into electricity
Many cells needed to produce a significant amount of energy

20. Ocean Thermal Energy Conversion (OTEC)
Produces electricity using the temperature difference between two layers of water.
Water boils at low temperatures when it is under low pressure in a vacuum chamber.

21. Methane (Biogas) Methane can be used to generate electricity and heat.
Dung-fired power stations produce electricity.
Methane from landfills can generate electricity.

22. Alcohol Ethanol can be made by fermenting fruit or agricultural waste.
Produces less air pollution

23. Hydrogen Most abundant element in the universe. Can be burned as fuel
Does not release pollutants when burned
Produces water as by-product.

24. Nuclear power
uranium fuel rods
Nuclear power stations use a certain type of uranium to produce heat energy.
This heat energy is used to produce steam. The steam is then used to drive turbines which turn electrical generators.
Energy changes:
nuclear
to thermal
to kinetic
to electrical

26. A nuclear reactor

27. Problems with nuclear power stations
Nuclear fuel (uranium) does not produce greenhouse gases and it generates times more energy per kilogram than fossil fuels.
However:
Nuclear waste is radioactive and may have to be stored safely for thousands of years.
Although safe in normal operation, accidents can release radioactive material over a large area. The area around Chernobyl in Ukraine has been closed off since 1986.
The destroyed Chernobyl nuclear reactor

28. ADVANTAGES
Concentrated energy source
Reliable energy source
Can be built anywhere
No greenhouse gases
No acid rain
DISADVANTAGES
Non-renewable
Radioactive waste
Expensive to build
Technology is related to that needed to make atomic bombs

29. Fossil fuels Fossil fuels include coal, oil and natural gas.
They have been formed in the ground from dead vegetation and tiny creatures by a process that has taken millions of years.
When burnt the heat energy produced is used to produce steam.
The steam is then used to drive turbines which turn electrical generators.
Energy changes:
thermal
to kinetic
to electrical

30. Coal-fired power station

31. Problems with fossil fuels
Burning coal, gas and oil produces carbon dioxide. This is a greenhouse gas which causes global warming.
Fossil fuel burning can also produce sulfur dioxide gas. This can dissolve in water and produce acid rain which causes damage to forests and buildings.
Modern power stations remove most sulfur dioxide producing compounds before burning.
Fossil fuels are not renewable. They are running out.
An effect of acid rain

32. ADVANTAGES
Concentrated energy source
Reliable energy source
Can be built anywhere
DISADVANTAGES
Non-renewable
Produces greenhouse gases and contributes to global warming
Produces acid rain

33. Electricity generation pie-chart
Most of our electricity is generated by burning fossil fuels (74% according to the pie chart opposite)
Nearly 20% is nuclear
Less than 5% is currently generated using renewable sources.