17
Electricity and Your Community
Think About It Date
Page R16 Page #
· What is electric
energy?
· What are some
consequences of not
having electricity when
it is needed?
Electricity and Your Community
Investigate Part A Date
Pages R17-18 Page #
1a. List the three
countries that generate
the most electricity.
1b. What type of
electricity generation is
used most by these
areas? Least?
1c. List the three
countries that generate
the least electricity.
1d. What type of
electricity generation is
used most by these
areas? Least?
1e. How do the resources
for electricity generation
differ between the top
and bottom regions?
how do you account
for the differences?
2a. Rank global
electricity generation by
fuel type from highest
to lowest.
2b. Rank U.S. energy
generation by fuel type
from highest to lowest.
2c. How does the
electricity generated in
the U.S. match global
electricity generation?
Explain.
3a. Make a graph.
Electricity and Your Community
Investigate Part B Date
Pages R18-19 Page #
1a. Is your state a net
importer or exporter of
electricity? What does
this mean?
1b. What energy
resources are used to
generate electricity in
your state?
1c. Which energy
resource does your
state depend upon the
most to generate
electricity?
1d. What are the trends
in energy resource use
for electric power
generation in your
state over time?
1e. How has the
generation of electricity
changed in your state
over time? How much
has it grown in the last
10 years? Explain.
1f. How does the growth
in electricity generation
in your state compare to
the rate of population
growth in your state?
How might you explain
this relationship?
1g. How do the types of
resources used by your
state for electricity
generation compare with
the averages for the
world and the U.S.?
1h. What sector
consumes the most
energy for electricity
in your state? Least?
1i. What resources does
your state use most for
residential and
commercial purposes?
For transportation? For
industry?
2a. How does the data
help you meet your
Chapter Challenge?
Electricity and Your Community
Digging Deeper Date
Pages R19-22 Page #
Nuclear fission the process by which large atoms are split into two parts, with conversion of a small part of the matter into energy
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0702/es0702page01.cfm?chapter_no=07
Electric power power associated with the generation and transmission of electricity
It is the rate at which electricity does work—measured at a point in time—in watts
Capacity/capability the maximum amount of electric power that a piece of electrical equipment can accommodate
Electric energy energy associated with the generation and transmission of electricity
It is the amount of work that can be done by electricity in watt-hours
Example a 1200-W hair dryer used for 15 minutes would require 300 Wh of electrical energy
Fossil fuels fuel derived from materials (mainly coal, petroleum and natural gas) that were generated from fossil organic matter and stored deep in the Earth for geologically long times
They supply about 70% of the energy sources for electricity in the U.S.
Burning fossil creates a variety of gases and
fuels particulates that, if not captured by pollution control equipment, are released into the atmosphere
Geothermal energy energy derived from hot rocks and/or fluids beneath the Earth’s surface
http://www1.eere.energy.gov/geothermal/gpp_animation.html
Photovoltaic energy energy associated with the direct conversion of solar radiation to electricity
http://www1.eere.energy.gov/solar/video/pv4.mov
Turbine a rotating machine or device that converts the mechanical energy of fluid flow into mechanical energy of rotation of a shaft
Turbines provide most of the electricity in the United States
How turbines water is heated to produce steam,
produce electricity which is put under pressure to turn the turbine
The turbine powers a generator that produces electricity
Renewable energy an energy source that is powered
source by solar radiation at the present time rather than by fuels stored in the Earth
Hydroelectric power electrical power derived from the flow of water on the Earth’s surface
http://www.ucopenaccess.org/courses/APEnvSci/course%20files/multimedia/lesson68/animations/4e_hydroelectric_power.html
Hydroelectric power 70% is generated in the Pacific
in the United States and Rocky Mountain States
Two basic types 1. falling water
of systems 2. natural river current
Falling water system water accumulates in reservoirs created by dams
The water falls through conduits and applies pressure against the turbine blades to drive the generator to produce electricity
Run-of-the-river the force of the river current
system applies pressure to the turbine blades to produce electricity
Both systems depend upon seasonal changes and stream flow
Advantages •water is a renewable resource
•cheap source of power
•little air pollution
•can start quickly (because they don’t need to wait for water to turn to steam)
•flow of water can be adjusted quickly during peak demands for electricity
Limitations •environmental impacts from damming rivers and streams
→ affects the habitats of local plants and animals
•depends on flow of water, which can vary with seasons and during droughts
Renewable resources currently supply less than 1% of
(other than water) the electricity generated by electric utilities
They include:
•solar
•wind
•biomass
Geothermal energy although it is considered a nonrenewable energy, we will not run out of it
Most of the heat needed for geothermal energy is found at depths beyond current drilling methods
Most geothermal plants in the U.S. are found in the western states where magma is close enough to the surface to supply steam for use in conventional steam-turbine plants
Electricity and Your Community
Check Your Understanding Date
Page R22 Page #
1. What is the difference
between electric energy
and electric power?
2. Compare and contrast
steam turbine versus
hydroelectric power
generation. How are
they similar/different?
3. What are the
advantages and
disadvantages of
hydroelectric power?
4. Explain why biomass
and wind are called
renewable energy
sources.
Electricity and Your Community
Understanding and Applying Date
Pages R23-24 Page #
1a. Which of the energy
sources are nonrenewable?
What percentage of
energy consumed to
produce electricity in 1999
did they represent?
1b. Which of the energy
sources are renewable?
What percentage of
energy consumed to
produce electricity in 1999
did they represent?
1c. What was the
efficiency of electricity
generation in the U.S.?
1d. Explain what is
meant by “conversion
losses accounted for
21.89 quads of the energy
consumed to generate
electricity” in relation to
question 1c.
2a. Calculate the net
efficiency of a home
water heater.
2b. Why is generation
of electricity the lowest
efficiency of this process?
3a. How many tons of
coal per year does this
equate to?
3b. How many gallons
of gasoline does this
equate to?
3c. If the U.S. increased
its use of solar energy 5%
annually, how many tons
of coal would this equate
to during the next 10
years?
Electricity and Your Community
Inquiring Further Date
Pages R24 Page #
1. Storage of solar
energy
How do car batteries
perform in comparison
to solar batteries in
solar systems?
2. Energy from the
oceans
Choose one of the three
ways that have been
proposed to use the
energy of the oceans
for electrical generation:
· tides
· waves
· vertical temperature
differences
Research the theory and
techniques involved in
its use for generating
electricity.
3. Other methods of
generating electricity
Research one of the
following methods of
generating electricity.
· photovoltaics
· geothermal
· solar thermal
How does it work?
Where is it being used?
What are the ideal
conditions for using this
alternative? What are
the advantages of these
methods over fossil fuels?
What are the
disadvantages or
limitations?