UNIT 15 – SOURCES OF UNIT 15 – SOURCES OF ENERGYENERGY

ENERGY FROM THE SUNENERGY FROM THE SUN

Also called solar energyAlso called solar energyGives us heat and light Gives us heat and light

energyenergyUsed in:Used in:

1. Photosynthesis 1. Photosynthesis

(light energy chemical (light energy chemical potential energy)potential energy)

Energy from the sun…Energy from the sun…

2. Solar cells/panels2. Solar cells/panels

(light energy electrical energy)(light energy electrical energy)

Solar cells

Energy from the sun…Energy from the sun…

3.3. SatellitesSatellites

(light energy (light energy electrical energy)electrical energy)

What are the other uses What are the other uses of the energy we get of the energy we get from the sun?from the sun?

ENERGY FROM RUNNING WATERENERGY FROM RUNNING WATER

HYDROELECTRIC POWER STATIONHYDROELECTRIC POWER STATION

- makes use of a dam to hold back water- makes use of a dam to hold back water

- stored water has gravitational potential energy- stored water has gravitational potential energy

- electrical energy obtained from running water - electrical energy obtained from running water is known as hydroelectric energyis known as hydroelectric energy

- Energy conversion:- Energy conversion:

gravitational potential energy kinetic energygravitational potential energy kinetic energy

electrical energyelectrical energy

Hydroelectric Power StationHydroelectric Power Station

Energy from running water…Energy from running water…

WAVE POWER STATIONWAVE POWER STATION

- uses kinetic energy of the waves and - uses kinetic energy of the waves and converts it into electrical energyconverts it into electrical energy

- Energy conversion:- Energy conversion:

kinetic energy electrical energykinetic energy electrical energy

ENERGY FROM WINDENERGY FROM WIND

WINDMILLSWINDMILLS

Energy conversion:Energy conversion:

kinetic energy (wind) mechanical energy (in kinetic energy (wind) mechanical energy (in the gear system)the gear system)

- the mechanical energy is used to grind food- the mechanical energy is used to grind food WIND FARMSWIND FARMS

kinetic energy (wind) electrical energykinetic energy (wind) electrical energy

- the electrical energy is used to generate - the electrical energy is used to generate electricityelectricity

Energy from Wind… WINDMILLEnergy from Wind… WINDMILL

Energy from Wind… WIND FARMEnergy from Wind… WIND FARM

ENERGY FROM FUELSENERGY FROM FUELS

All fuels store chemical potential energyAll fuels store chemical potential energyExamples are coal, petrol and natural gasExamples are coal, petrol and natural gasEnergy conversion:Energy conversion:

chemical potential energy heat and chemical potential energy heat and light energylight energy

Energy from fuels used in:Energy from fuels used in:

INDUSTRIAL MACHINES

POWER STATIONS

VEHICLES

COOKING

ENERGY FROM BIOFUELSENERGY FROM BIOFUELS

Extracted from vegetables and beansExtracted from vegetables and beansUsed as an alternative source of energy Used as an alternative source of energy

just like solar, water and wind energy just like solar, water and wind energy

SAFETY PRECAUTIONS IN USING SAFETY PRECAUTIONS IN USING FUELSFUELS

Store liquid fuels in a cool and dry place.Store liquid fuels in a cool and dry place.Store liquid fuels away from the sun to Store liquid fuels away from the sun to

avoid being heated up and starting fire.avoid being heated up and starting fire.Do not play with matches or play with Do not play with matches or play with

sparklers near areas where fuels are sparklers near areas where fuels are stored.stored.

Do not use charcoal indoors. Charcoal Do not use charcoal indoors. Charcoal may emit poisonous fumes.may emit poisonous fumes.

LIMITED AND RENEWABLE LIMITED AND RENEWABLE SOURCES OF ENERGYSOURCES OF ENERGY

Limited sources of energy are:Limited sources of energy are:

- fuels such as coal, oil, petrol and natural - fuels such as coal, oil, petrol and natural gasgas

Renewable sources of energy are:Renewable sources of energy are:

- sun, running water, wind and biofuels- sun, running water, wind and biofuels

CONSERVING ENERGYCONSERVING ENERGY

Walk or ride a bicycle if you are going to a Walk or ride a bicycle if you are going to a nearby place.nearby place.

Turn off electrical appliances when they Turn off electrical appliances when they are not in use.are not in use.

What are the other ways of conserving What are the other ways of conserving energy at home or in school?energy at home or in school?

SourcesSources

http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/photosynth.gifhttp://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/photosynth.gif http://www.poolcenter.com/HowSolarWorks.jpghttp://www.poolcenter.com/HowSolarWorks.jpg http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Solar_panels_closeup.jpg/http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Solar_panels_closeup.jpg/

800px-Solar_panels_closeup.jpg800px-Solar_panels_closeup.jpg http://sites.google.com/site/webtermproject/eNERGIES.jpghttp://sites.google.com/site/webtermproject/eNERGIES.jpg http://news.bbc.co.uk/olmedia/1030000/images/_1032148_wave_generator_inf300.gifhttp://news.bbc.co.uk/olmedia/1030000/images/_1032148_wave_generator_inf300.gif