ENERGY FROM THE SUN • Also called solar energy • Gives us heat and light energy • Used in: 1. Photosynthesis (light energy chemical potential energy)
Energy from the sun… 2. Solar cells/panels (light energy electrical energy) Solar cells
Energy from the sun… • Satellites (light energy electrical energy) What are the other uses of the energy we get from the sun?
ENERGY FROM RUNNING WATER • HYDROELECTRIC POWER STATION - makes use of a dam to hold back water - stored water has gravitational potential energy - electrical energy obtained from running water is known as hydroelectric energy - Energy conversion: gravitational potential energy kinetic energy electrical energy
Energy from running water… • WAVE POWER STATION - uses kinetic energy of the waves and converts it into electrical energy - Energy conversion: kinetic energy electrical energy
ENERGY FROM WIND • WINDMILLS Energy conversion: kinetic energy (wind) mechanical energy (in the gear system) - the mechanical energy is used to grind food • WIND FARMS kinetic energy (wind) electrical energy - the electrical energy is used to generate electricity
ENERGY FROM FUELS • All fuels store chemical potential energy • Examples are coal, petrol and natural gas • Energy conversion: chemical potential energy heat and light energy
Energy from fuels used in: COOKING VEHICLES POWER STATIONS INDUSTRIAL MACHINES
ENERGY FROM BIOFUELS • Extracted from vegetables and beans • Used as an alternative source of energy just like solar, water and wind energy
SAFETY PRECAUTIONS IN USING FUELS • Store liquid fuels in a cool and dry place. • Store liquid fuels away from the sun to avoid being heated up and starting fire. • Do not play with matches or play with sparklers near areas where fuels are stored. • Do not use charcoal indoors. Charcoal may emit poisonous fumes.
LIMITED AND RENEWABLE SOURCES OF ENERGY • Limited sources of energy are: - fuels such as coal, oil, petrol and natural gas • Renewable sources of energy are: - sun, running water, wind and biofuels
CONSERVING ENERGY • Walk or ride a bicycle if you are going to a nearby place. • Turn off electrical appliances when they are not in use. What are the other ways of conserving energy at home or in school?
Sources • http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/photosynth.gif • http://www.poolcenter.com/HowSolarWorks.jpg • http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Solar_panels_closeup.jpg/800px-Solar_panels_closeup.jpg • http://sites.google.com/site/webtermproject/eNERGIES.jpg • http://news.bbc.co.uk/olmedia/1030000/images/_1032148_wave_generator_inf300.gif