2 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
3 The 9 types of energy Type 3 example sources Heat Kinetic (movement) NuclearSoundLightChemicalElectricalGravitational potentialElastic potential
4 Electricity Light + heat Energy changesTo describe an energy change for a light bulb we need to do 3 steps:1) Write down the starting energy:3) Write down what energy types are given out:2) Draw an arrowElectricity Light + heatWhat are the energy changes for the following…?An electric fireA rock about to dropAn arrow about to be fired
5 Conservation of Energy In any energy change there is ALWAYS some “waste” energy:e.g. a light bulb:Electricity Light heatIn 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.
6 Heat 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:
7 Power stationsGeneratorTurbineCooling towerTransformerBoiler
8 What does each part do?The boiler is where the fuel is burnt to boil waterThe steam from the boiler is used to turn a turbineThe turbine is connected to the generator, which acts like a dynamo – it generates electricity out of movementThe steam is cooled down and turned back into water in the cooling tower
9 Renewable vs. non-renewable fuels 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
10 Non-renewable energy sources AdvantagesDisadvantagesPollution – CO2 leads to global warming and SO2 leads to acid rainCheap fuel costsCoal, oil, gas and nuclearGood for “basic demand”Fuel will run outCosts a lot of money to decommission a nuclear plantShort start-up time
11 Other ways of generating electricity… Can we drive the turbine without burning anything?
12 Other ways of generating electricity… WindHydro-electricWaveTidal
13 Renewable energy sources AdvantagesDisadvantagesOften depend on the weather – is it sunny???CleanCoal, oil, gas and nuclearWon’t run outVery expensiveEnergy is “dilute” – in other words, it’s very spread outEasily accessible