KS3 EnergyKS3 Energy

The ULTIMATE energy The ULTIMATE energy sourcesource

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

The 9 types of energyThe 9 types of energyType 3 example sources

Heat

Kinetic (movement)

Nuclear

Sound

Light

Chemical

Electrical

Gravitational potential

Elastic potential

Energy changesEnergy changesTo describe an energy change for a light bulb we need to do 3 steps:

Electricity Light + heat

1) Write down the starting energy:

3) Write down what energy types are given out:

2) Draw an arrow

What are the energy changes for the following…?

1) An electric fire

2) A rock about to drop

3) An arrow about to be fired

Conservation of EnergyConservation of EnergyIn any energy change there is ALWAYS some “waste” energy:

e.g. a light bulb:

Electricity Light + heat

In this example HEAT is wasted – it’s given to the surroundings. Waste energy is virtually

always heat and it’s always given to the surroundings.

Heat transferHeat transfer1) 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:

Power stationsPower stations

Cooling tower

Turbine

Generator

Transformer

Boiler

What does What does each part each part

do?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

Renewable vs. non-renewable Renewable vs. non-renewable fuelsfuels

A ________ energy source is blatantly one that can be _______ (“renew = make again”), e.g. _____, solar power etc. Biomass is also an example of a renewable energy source – ______ is a form of biomass.

A ___________ energy source is one that when it has been used it is gone forever. The main examples are ____, oil and gas (which are called ______ ____, as they are made from fossils), and nuclear fuel.

Words to use – non-renewable, coal, wind, renewable, fossil fuels, wood, renewed

Non-renewable energy Non-renewable energy sourcessources

Coal, oil, gas and nuclear

Advantages Disadvantages

Cheap fuel costs

Short start-up time

Good for “basic demand”

Fuel will run out

Costs a lot of money to

decommission a nuclear plant

Pollution – CO2 leads to global warming and SO2 leads to

acid rain

Other ways of generating Other ways of generating electricity…electricity…

Can we drive the turbine without burning anything?

Other ways of generating Other ways of generating electricity…electricity…

Wind

TidalWave

Hydro-electric

Renewable energy Renewable energy sourcessources

Coal, oil, gas and nuclear

Advantages Disadvantages

Clean

Easily accessible

Won’t run out Very expensive

Energy is “dilute” – in

other words, it’s very spread out

Often depend on the weather – is it

sunny???