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Sources of Energy. TEKS 5.7.C Energy Sources. Engage. Which of the following slides show a source of energy for our homes, cars, etc. ? As we scroll through the slides raise your hand when you see one that shows a source of energy. Amazon River Dam. Coal. Gasoline. Nuclear Reactors.
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Sources of Energy TEKS 5.7.C Energy Sources
Engage • Which of the following slides show a source of energy for our homes, cars, etc. ? • As we scroll through the slides raise your hand when you see one that shows a source of energy.
Which were sources of energy? • All of them were sources of energy. • Now explore some of them with your lab groups.
Let’s Explain • Energy is the ability to do work. • Alternative energy refers to energy sources, which are not based on the burning of fossil fuels or the splitting of atoms.
Why should we use alternative energy sources? • Fossil fuel is non renewable and there is a limited supply • Fossil fuels pollute • Nuclear power plants are too dangerous and generate radioactive waste
Alternatives • There are many means of harnessing energy, which have less damaging impacts on our environment. • Here are some possible alternatives: • Solar • Wind • Geothermal • Biofuels • Hydroelectric
Solar • The total energy we receive each year from the sun is around 35,000 times the total energy used by man. • Solar energy is presently being used on a small scale for homes, but it has the potential to be used for much larger applications. • Must have a sunny day to harvest this energy – weather dependent • It is non-polluting and will not run out.
Wind • Wind power is an alternative energy source that does not pollute and will not run out. • Like solar power, harnessing the wind is highly dependent upon weather and location.
Geothermal • Geothermal energy is obtained from the internal heat of the planet and can be used to generate steam to run a steam turbine. This in turn generates electricity. • Geothermal energy is also non-polluting and should not run out.
Biofuel Unlike other renewable energy sources, biomass can be converted directly into liquid fuels, called "biofuels," to help meet transportation fuel needs. The two most common types of biofuels in use today are ethanol and biodiesel.
Ethanol • Ethanol is an alcohol. It is most commonly made by fermenting any biomass high in carbohydrates through a process similar to beer brewing. • Corn and sugar cane are commonly used for ethanol production. • Ethanol is mostly used as a blending agent with gasoline to increase octane and cut down carbon monoxide and other smog-causing emissions.
Biodiesel • Biodiesel is made by combining alcohol (usually methanol) with vegetable oil, animal fat, or recycled cooking grease. It can be used as an additive to reduce vehicle emissions or in its pure form as a renewable alternative fuel for diesel engines. • Algae is now being used to produce biodiesel.
Hydroelectric • Hydroelectricity comes from the damming of rivers and utilizing the potential energy stored in the water. As the water stored behind a dam is released at high pressure, its kinetic energy is transferred onto turbine blades and used to generate electricity. • This system has enormous costs up front, but has relatively low maintenance costs and provides power quite cheaply. • Hydroelectricity is a renewable energy source.
