Transcript energy - Cloudfront.net

May 20, 2015
SA: Ch: 5 Sec: 3 Part 3 “Alternative Resources”
EQ: What are two ways to release biomass
energy?
Questions
Where would you build a hydroelectric power
plant? Why?
Come in Quietly
and sit at your
desk, open to
your notes, write
the new question,
and wait quietly
for class to begin.
Agenda
1. Roll
2. Chapter 5 Section 3
Part 3
“Alternative Resources”
1. Video: “How Stuff
Works: Corn”
Hydroelectric Energy
The energy of falling water has been used
by humans for thousands of years.
Hydroelectric Energy
Water wheels have been used to provide
energy to factories.
Water Wheels
Falling water turns water wheels, which
turns giant millstones used to grind grain
for flour.
Hydroelectric Energy
Electricity produced by falling water is called
hydroelectric energy.
Falling Water
Falling water turns
huge turbines inside
hydroelectric dams,
generating electricity
for millions of people.
Hydroelectric Energy
Hydroelectric energy is inexpensive and
produces little pollution.
Hydroelectric Energy
Hydroelectric energy is renewable, because
water constantly cycles through the water
cycle.
Hydroelectric Energy
The building of
dams can disrupt
the life cycle of
animals causing
them to die,
decrease water
quality and
create erosion
problems.
Powerful Plants
Plants are similar to solar collectors,
absorbing energy from the sun and storing
it for later use.
Powerful Plants
Leaves, wood, and other parts of plants
contain stored energy.
Powerful Plants
Even dung of plant grazing animals is high
in stored energy.
Biomass
Biomass is organic matter that contains
stored energy.
Biomass
Biomass energy can be released in several
ways. The most common way is by
burning.
Animal Dung
In many parts of the world where firewood is
scarce, people burn animal dung for
energy.
Biomass
The United Nations scientists estimate that
burning of wood and animal dung
accounts for about 14% of the worlds total
energy use.
Powerful Plants
Plant material can be changed into liquid
fuel. Starch in the plants can be changed
into alcohol.
Gasohol
The 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 Heat
Can we tap into the energy of the Earth?
Geothermal Energy
Geothermal energy is the energy produced
by the heat within the Earth’s crust.
Geothermal Energy
In some places rainwater will penetrate rock
and be heated by the magma creating
steam.
Holes in the Earth’s Surface
Natural holes in the Earth’s surface allow hot
water and steam to escape from the
Earth’s crust.
Geothermal Power Plant
Some geothermal power plants use primarily
steam to generate electricity.
How a Geothermal Power Plant
Works
1. Steam rises through a well.
How a Geothermal Power Plant
Works
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.
Geothermal Energy
Geothermal energy can also be used as a
direct source to heat buildings.
“How Stuff Works: Corn”
1. What did you know?
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2. What did you learn?
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3. What do you want to know?
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Review
1. 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.