Renewable and non-renewable energy sources
Hany El-Gezawy 2012-2013
Hany El-Gezawy 2012-2013
Hany El-Gezawy 2012-2013
Hany El-Gezawy 2012-2013
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.
Examples include wind, hydroelectric, wave, tidal, solar and geothermal.
Fossil fuels such as coal. gas and oil as well as uranium are non-renewable energy sources.
Hany El-Gezawy 2012-2013
Hydroelectric powerFalling water is used to drive a turbine which rotates an electrical generator.
Energy changes:
gravitational potential
to kinetic
to electrical
Hany El-Gezawy 2012-2013
Hydroelectric power station
Hany El-Gezawy 2012-2013
ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time
DISADVANTAGES• Very limited locations• Wildlife affected• Expensive to build
TRIPLE ONLY
The Hoover Dam near Las Vegas
Hany El-Gezawy 2012-2013
Wave power
Waves can be used to drive an electrical generator.
Energy changes:
kinetic
to electrical
Hany El-Gezawy 2012-2013
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
TRIPLE ONLY
Hany El-Gezawy 2012-2013
Tidal powerMoving water caused by the tides is used to drive a turbine directly which rotates an electrical generator.
Energy changes:gravitational potentialto kinetic to electrical
Tidal power station at La Rance, Brittany
Hany El-Gezawy 2012-2013
Tidal power stationHany El-Gezawy 2012-2013
ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time
DISADVANTAGES• Very limited locations• Wildlife affected• Expensive to build
TRIPLE ONLY
Proposed Severn Estuary Tidal Power Scheme
Hany El-Gezawy 2012-2013
Wind power
Wind is used to rotate a turbine (the blades) which turns an electrical generator.
A wind farm
Energy changes:
kinetic
to electrical
Hany El-Gezawy 2012-2013
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• Danger to wildlife
TRIPLE ONLY
Hany El-Gezawy 2012-2013
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
Hany El-Gezawy 2012-2013
ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Short start up time
DISADVANTAGES• Very limited locations• Expensive to build
TRIPLE ONLY
Hany El-Gezawy 2012-2013
Solar heatingHeat energy from the Sun is focussed onto pipes containing water. The water boils producing steam. The steam is then used to drive turbines which turn electrical generators.
Energy changes:thermalto kinetic to electrical
Hany El-Gezawy 2012-2013
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
TRIPLE ONLY
Hany El-Gezawy 2012-2013
Solar cells
Electricity produced directly from the Sun’s radiation.
Energy changes:
light
to electrical
Hany El-Gezawy 2012-2013
ADVANTAGES • Renewable • No greenhouse gases• No acid rain• No radioactive waste• Instant start up time
DISADVANTAGES• Unreliable in the UK! –
sunshine is needed for solar cells
• Can only be used during the day
• Only 10% of solar energy is converted into electricity by solar cells
• Many cells needed to produce a significant amount of energy
TRIPLE ONLY
Hany El-Gezawy 2012-2013
Nuclear powerNuclear 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:nuclearto thermalto kinetic to electrical
uranium fuel rods
Hany El-Gezawy 2012-2013
A nuclear reactor
Hany El-Gezawy 2012-2013
Problems with nuclear power stationsNuclear fuel (uranium) does not produce greenhouse gases and it generates 10000 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
TRIPLE ONLY
Hany El-Gezawy 2012-2013
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
TRIPLE ONLY
Hany El-Gezawy 2012-2013
Fossil fuelsFossil 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:thermalto kinetic to electrical
Hany El-Gezawy 2012-2013
Coal-fired power stationHany El-Gezawy 2012-2013
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. Estimates vary between 50 to 200 years to when we will need to find alternative sources of energy.
An effect of acid rain
TRIPLE ONLY
Hany El-Gezawy 2012-2013
ADVANTAGES • Concentrated energy source
• Reliable energy source• Can be built anywhere• No radioactive waste
DISADVANTAGES• Non-renewable• Produces greenhouse gases and contributes to global warming
• Produces acid rain
TRIPLE ONLY
Hany El-Gezawy 2012-2013
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.
Hany El-Gezawy 2012-2013