KS3 Energy

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KS3 Energy
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The ULTIMATE energy source
The sun is the ultimate source of all our
energy. For example, we often get energy from
beef BEEF comes from COWS, COWS eat
GRASS, GRASS gets energy from the sun by
PHOTOSYNTHESIS
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The 9 types of energy
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Current in a series circuit
In other words, the current in a series circuit
is THE SAME at any point
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Current in a parallel circuit
A PARALLEL circuit is one where the current has a
choice of routes
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Energy changes
To describe an energy change for a light bulb we
need to do 3 steps

• What are the energy changes for the following?
• An electric fire
• A rock about to drop
• An arrow about to be fired

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Conservation of Energy
In any energy change there is ALWAYS some waste
energy e.g. a light bulb
Electricity Light heat
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Heat transfer
1) Conduction this is when heat is passed on
through a solid by vibrations of particles
2) Convection this is when heated stuff moves
somewhere else and takes heat with it
3) Radiation this is when heat is moved by
heat waves (infra-red) this is how heat
reaches us from the sun
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Power stations
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What does each part do?
The boiler is where the fuel is burnt to boil
water
The steam from the boiler is used to turn a
turbine
The turbine is connected to the generator, which
acts like a dynamo it generates electricity out
of movement
The steam is cooled down and turned back into
water in the cooling tower
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Non-renewable energy sources
Advantages
Disadvantages
Pollution CO2 leads to global warming and SO2
leads to acid rain
Cheap fuel costs
Good for basic demand
Fuel will run out
Costs a lot of money to decommission a nuclear
plant
Short start-up time
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Other ways of generating electricity
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Other ways of generating electricity
Wind
Hydro-electric
Wave
Tidal
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Renewable energy sources
Advantages
Disadvantages
Often depend on the weather is it sunny???
Clean
Wont run out
Very expensive
Energy is dilute in other words, its very
spread out
Easily accessible