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QuestionsWhere would you build a hydroelectric power
plant? Why?
SA: Ch: 5 Sec: 3 Part 3 “Alternative Resources”EQ: What are two ways to release biomass
energy?
May 20, 2015
Agenda
1.Roll
2.Chapter 5 Section 3 Part 3
“Alternative Resources”
1.Video: “How Stuff Works: Corn”
Come in Quietly and sit at your desk, open to your notes, write the new question, and wait quietly for class to begin.
Hydroelectric EnergyThe energy of falling water has been used
by humans for thousands of years.
Water wheels have been used to provide energy to factories.
Hydroelectric Energy
Water WheelsFalling water turns water wheels, which
turns giant millstones used to grind grain for flour.
Electricity produced by falling water is called hydroelectric energy.
Hydroelectric Energy
Falling WaterFalling water turns
huge turbines inside hydroelectric dams, generating electricity for millions of people.
Hydroelectric Energy
Hydroelectric energy is inexpensive and produces little pollution.
Hydroelectric EnergyHydroelectric energy is renewable, because
water constantly cycles through the water cycle.
Hydroelectric EnergyThe building of
dams can disrupt the life cycle of animals causing them to die, decrease water quality and create erosion problems.
Powerful PlantsPlants are similar to solar collectors,
absorbing energy from the sun and storing it for later use.
Leaves, wood, and other parts of plants contain stored energy.
Powerful Plants
Even dung of plant grazing animals is high in stored energy.
Powerful Plants
BiomassBiomass is organic matter that contains
stored energy.
BiomassBiomass energy can be released in several
ways. The most common way is by burning.
Animal DungIn many parts of the world where firewood is
scarce, people burn animal dung for energy.
BiomassThe United Nations scientists estimate that
burning of wood and animal dung accounts for about 14% of the worlds total energy use.
Powerful PlantsPlant material can be changed into liquid
fuel. Starch in the plants can be changed into alcohol.
GasoholThe alcohol is burned as a fuel or mixed with
gasoline to make a fuel mixture called gasohol.
Math Break
Imagine that you own a car the runs on alcohol made from corn that you grow. You drive your car about 15,000 miles a year, and you get 240 gallons of alcohol from each acre of corn that you process. If your car gets 25 mi/gal, how many acres of corn would you have to grow to fuel you car for a year?
Deep HeatCan we tap into the energy of the Earth?
Geothermal EnergyGeothermal energy is the energy produced
by the heat within the Earth’s crust.
In some places rainwater will penetrate rock and be heated by the magma creating steam.
Geothermal Energy
Holes in the Earth’s SurfaceNatural holes in the Earth’s surface allow hot
water and steam to escape from the Earth’s crust.
Geothermal Power PlantSome geothermal power plants use primarily
steam to generate electricity.
How a Geothermal Power Plant Works
1. Steam rises through a well.
2. The steam drives turbines, which in turn drive electric generators.
How a Geothermal Power Plant Works
3. The generators produce electricity.
How a Geothermal Power Plant Works
4. The steam escapes the power plant through vents.
How a Geothermal Power Plant Works
5. Leftover liquid water is injected back into the hot rock.
How a Geothermal Power Plant Works
Geothermal energy can also be used as a direct source to heat buildings.
Geothermal Energy
“How Stuff Works: Corn”
1. What did you know?_______________________________________________________________________________________________________________________________________2. What did you learn?_______________________________________________________________________________________________________________________________________3. What do you want to know?_______________________________________________________________________________________________________________________________________
Review1. Where would you build a hydroelectric power
plant? Why?Response: A hydroelectric power plant must be built in an area where … because …
2. What are two ways to release biomass energy?Response: Two ways to release biomass energy are …
3. What are two ways to use geothermal energy?Response: Two ways to use geothermal energy are …
4. Name one alternative to fossil fuels and name an advantage and a disadvantage to using that alternative resource.
