Louisiana Team AgEd
Louisiana Agriscience Education Curriculum
Course:
Agriscience I
Unit:
Energy
Lesson:
Alternative Energy Sources for Agriculture
LOUISIANA LEARNING STANDARDS AND GRADE LEVEL EXPECTATIONS
Learning Standards (LS):


The student will be able to recognize the environmental effects of using
alternative fuels
The student will be able to describe the pros and cons of using alternative fuels
Grade Level Expectations (GLE)
 Explain why ecosystems require a continuous input of energy from the Sun (LSH-E1
 Evaluate whether a resource is renewable by analyzing its relative regeneration
time (SE-H-B1
PERFORMANCE-BASED LEARNING OBJECTIVES. Instruction in this lesson should
result in students being able to:
1. Recognize the environmental effects of using alternative fuels.
2. Describe the pros and cons of using alternative fuels.
LIST OF RESOURCES. Teachers may find the following resources useful in planning
and teaching this lesson:
Textbooks
 Bernstein/Winkler/Zierdt – Warshw Environmental Science Ecology and Human
Impact Addison-Wesley Publishing Company 1996 (Chapters 16 and 17)
 Christensen, John et.al. Global Science Dubuque, Iowa: Kendall/Hunt
Publishing Company 2000 (Textbook Chapters 7, 9, and 10)
Web Sites
 http://www.eereenergy.gov
 http://www.helixcharter.net
 http://www.biomassenergycentre.org
 http://www.energyquest.com
 http://www.findsolar.com
 http://www.ucsua.org/clean-energy/renewable_energy_basics
 http://www.howstuffworks.com
 http://www.freeenergy.com
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

http://windenergyworks.org
http://eia.doe.gov
http://www.eia.doe.gov/cneaf/alternate/page/renewenergyconsump/figure1.html
Other Resources. The following resources will be useful to students and teachers:
 None
TERMS.
The following terms are presented in this lesson:
 Solar Energy –
 Hydroelectric Power
 Wind Energy
 Biomass Fuels
 Geothermal Energy
 Nuclear Energy
 Tidal Energy
LIST OF EQUIPMENT, TOOLS, SUPPLIES, AND FACILITIES
 Computer with power point
 Projector
 Internet access
 Writing Surface
INTEREST APPROACH. Use an interest approach that will prepare students for the
lesson. Teachers often develop an approach for their unique class and student
situations. A possible approach is included here.
You and a friend are watching T.V. and view a program about solar energy use and
solar homes. After viewing the program your friend is interested in converting his home
into a solar home, however he does not know how much the equipment will cost and the
savings provided each month.
Both of you have heard that solar power is
environmentally friendly, but do not want to spend all of your savings on the equipment.
In this activity students will research how to convert their current home or example
home to a solar power home. Each student will be required to find out the amount of
kilowatts and impact a monthly electric bill. This information will plug into the Find Solar
web site, www.findsolar.com. Students will be able to determine if conversion is
economical and environmental impact of using solar power. Research will be
compared/contrasted and debated in class, to determine feasibility. Have each student
indicate whether they would convert to solar power, and why or why not. (PS-H-F2), (D9-H)
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SUMMARY OF CONTENT AND TEACHING STRATEGIES
Anticipated Problem: What types of alternative energy sources are available today and
in the future for the agriculture industry?
1. Have students view pie chart that shows the amount of energy consumption in
the United States as of 2007.
a. According to the table alternative energy accounts for at least 15% of all
energy consumed.
Alternative Energy Sources used in Agriculture
Solar Energy – energy form the sun absorbed by the earth and used as a fuel by
virtually all organisms.
1. Energy from the sun drives the water cycle, causes winds to blow due to uneven
warming of the earth’s surface, waves to move, and impacts the earth’s climate.
2. Provides energy for photosynthesis
3. Produces thermal energy, which is when light energy from the sun that is
absorbed by dark colored objects. This energy can be used as a source of heat
or electricity
4. Solar energy is stored in plants and animals that died millions of years ago
forming fossil fuels.
Two types of solar heating systems are passive and active
1. Passive solar heating systems are designed so that the sun’s energy is collected,
stored, and distributed naturally in an enclosed dwelling. Passive solar energy is
used only as an alternative source of heat, reducing the need for fossil and
nuclear fuels.
a. This is the simplest and cheapest solar energy system. An example of a
passive solar heating system is a greenhouse.
b. Uses sunlight to provide light and heat directly, with no circulating fluid or
energy conversion systems.
c. Many homes in North America have large glass windows facing the south,
exposing rooms painted with dark colors. Positioning of a building has a big
impact on the efficiency of a passive solar heating system.
d. Some of examples of agricultural use of passive solar energy: Hay cut,
allowed to dry in the sun, and then stacked or baled for storage. Corn and
soybean crops partially dried in the field. Solar drying used to cure crops and
dry food for storage.
2. Active Solar Heating uses devices to collect, store, and circulate heat produced
form solar energy called flat plate collectors.
a. These collectors are installed in areas that will receive maximum sunlight.
The base is constructed of black metal and tubes filled with a fluid or air runs
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across the top of the metal. The top of the collector is made up of glass. The
black metal absorbs sunlight, heating liquid is pumped through the tubes,
which is stored until use, and clear glass is used to prevent heat form
escaping.
b. These types of systems can be used for producing heat and hot water. As
water-cools it is pumped back to the flat plate collector.
Photovoltaic Cells
1. Are the only solar devices that produce electricity?
2. Photovoltaic cells or solar cells are made up of two layers of semiconductor
elements such as silicon or selenium. One layer is positively charged and the
other is negatively charged as sunlight strikes the cells electrons move form the
negative to positive side. As a result of the electron movement electricity is
produced.
a. Cells are used today on space satellites and produce power for homes and
industry.
b. They are lightweight and last a long time.
Solar Energy can be used to heat building such as greenhouses, livestock
buildings to maintain animal health, provide hot water for cleaning pens and
equipment, and drying crops.
Photovoltaic Systems are used for electric fences, garden lights, water
pumps, pond aeration, and small irrigation systems.
Advantages and Disadvantages of Solar Energy
1. Free and unlimited, clean, nonpolluting, renewable resource, little maintained,
little noise and machinery involved.
2. Not a constant source (limited sunlight on cloudy or rainy days), upfront
equipment cost for capturing energy expensive, but these are usually offset over
time with savings in energy bill. As technology progresses equipment will be
more cost effective.
Hydroelectric Power – Electricity that is produced form the kinetic energy of
moving water.
1. Used for centuries to turn water wheels that would grind grains. In the 1800’s
turbines were invented that would produce electricity from flowing water. In 1925
40% of all the worlds’ electricity was generated by flowing water.
2. To generate power from water a dam is built across a waterway to create a
reservoir. Water behind the dam is directed toward turbine blades, which causes
turbine blades to turn. The coils spin through a magnetic field producing
electricity.
Advantages and Disadvantages of Hydroelectric power
1. Flood control, free, unlimited, nonpolluting, creates recreation areas, stores water
for irrigation. .
2. Alter s natural plant and animal life due to temperature changes. (Water is colder
on the upside of dam,) Some aquatic life cannot swim upstream, which
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interferers with reproduction. Erosion problems on the downside of dam due to
water not replenishing soil with nutrients.
Hydroelectric Power currently supplies about 24 percent of the world’s electricity. The
total amount of electric output in 2007 was about 675 megawatts, which is equal to 36
billion barrels of oil.
Tidal energy – Works Similar to hydroelectric energy using kinetic energy in ocean
tides converted into electricity by rotating turbines. Water is usually dammed in a
reservoir during high tides and released during low tides. As water moves form one
source to turbines rotate producing electricity. There are only a few suitable sites for
tidal energy generators around the world and a difference between 16 feet are needed
between high and low tides.
Wind Energy - generated by wind generators operated by wind rotating turbines
blades, and using kinetic energy to generate electricity
1. Since the 1870’s farmers have been using wind energy to pump water. During
the 1920’s wind power was being used to turn small electric generators, but
efforts were abandoned due to electrical grid connections.
2. Windmills used to generate electricity of called aero generators, which have air
vanes connected to coils of wire.
3. There are two types of aero generators horizontal and vertical axis.
a. Horizontal are shaped like airplane propellers and vertical are shaped like an
eggbeater. The vertical shape design allow for the generator turn at lower
speeds.
4. Wind farms are sites where many aero generators are located together in open
areas where wind conditions are favorable at least 15 mph everyday. For wind
generators to work effectively wind speeds must be between 14-15mph.
Advantages and Disadvantages of Wind Energy
1. Free unlimited, non-polluting, source of income for farmers on land lease without
interfering with crops and livestock, can be used to pump water.
2. Takes up a lot of land, zoning regulations, liability setting up to gird systems setup and equipment expensive. According to American wind energy association if
may take up to 15 years for a wind turbine to pay for itself.
As of 2007 wind there are wind farms in 32 states, they have supported 45,000 jobs
provided 1 % of all U.S. electricity and save at least 28 million tons carbon dioxide
emissions. Since 1980 cost for wind energy equipment has gone down by 90 percent.
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Biomass Fuels – fuels formed form living or recently living organisms. This includes
forest, agriculture, and food processing waste.
1. Examples of forest products – saw dust, bark, paper, pulp, scarp lumber, and
wood dust.
2. Examples of Agriculture/Food Waste – Fruit pits, pecan shells, rice hulls,
corncobs, manure, and sugar cane residue.
3. Biofuels (also called biomass fuels) are a renewable resource and energy is
released form them usually by burning of converting to solids, liquids, or gaseous
forms. After conversion the fuel can be used for electric power, heat, chemicals,
or other fuels,
4. Sewage treatment facilities can use anaerobic digestion to treat water and
produce methane gas, which may be used for heating (Anaerobic – without air)
a. Methane is a hydrocarbon, which is the main component of natural gas. As
organic materials breakdown methane is produced which can be collected
and used for heating?
b. Grain crops such as corn and sugar cane can be used to make ethanol which
is an alcohol made by yeast during fermentation. Alcohol is also a
hydrocarbon.
c. Oil-bearing plants, plants with high hydrocarbon contents such as algae have
components similar to diesel or other petroleum products.
5. Ethanol
a. Alcohol-based alternative fuel.
b. Made from corn, barley, wheat or “cellulose” sources.
c. Lower engine efficiency and “gas” mileage than gasoline.
d. Reduces harmful emissions compared to gasoline.
e. E-10 = 10% ethanol and 90% gasoline for all gasoline-powered vehicles.
f. E-85 = 85% ethanol and 15% gasoline for use in “flex-fuel” vehicles only.
6. Bio-diesel – Made from vegetable oils, animal fats or recycled restaurant
greases. Blends up to B20 (20% bio-diesel and 80% petroleum diesel) for most
diesel vehicles. 100% bio-diesel may require vehicle modifications. May not be
suitable for wintertime use. Lower fuel economy than petroleum diesel.
Domestically produced, renewable, safe, biodegradable, reduced air pollutants.
Advantages and Disadvantages of bio-fuels
1. Renewable resource reduces green house gases, low emissions, increase
economic growth and employment.
2. May decrease plant biodiversity, may cause food prices to increase due to a
decrease in avaible grain, Additional land required, emits more Nitrogen Oxides,
must be transported by truck or rail, does not flow well at low temperatures, May
be incompatible with internal seals and gaskets in older vehicles.
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Geothermal Energy – Heat energy generated within the earth.
1. Geothermal energy is heat given off by radioactive elements decaying deep
beneath the ground. Enough heat is generated to melt rock called magma. This
heat contains 50,000 times more energy than oil and natural gas.
2. Geothermal energy in use din regions where the Earth’s crust is thin enough to
let heat through. These regions are usually located along the edges of tectonic
plates where young volcanoes are found. (Alaska, California, Oregon, Nevada)
3. As water cones into contact with hot rocks it rises to the surface forming hot
springs and geysers. This water can be at least 200 degrees Celsius.
a. Cool water seeps into the earth’s crust is heated up then rises to the surface
and steam is collected. Power plants also drill holes in rock and pump cool
water into hot areas, then collect hot water and steam through additional
piping, which is used to turn turbines. Water is then returned back to the
original source.
4. There are three designs used to collect steam, Dry, Flash, and Binary. The
choice of each system depends on how water comes out as steam.
a. Dry – steam goes to the turbine is condensed to water and returned back.
b. Flash – hot water is depressurized into steam and used to drive turbines
c. Binary – hot water heats a second liquid with a lower boiling point and water
is returned back to source.
Largest U.S. geothermal plant is steam driven and is located North of San Francisco,
California. Geothermal Heat Pumps are used to heat and cool houses. These systems
transfer heat during winter and absorb heat during summer. Air or antifreeze is pumped
through pipes buried underground and recalculated back into the building. These
systems are environmentally clean heating/cooling systems
Advantages and Disadvantages of Geothermal Energy
1. Used to heat greenhouses, de-ice roads, and dry out fish, heat water for aquatic
farms, and heat and cool homes. Ireland gets 50% of energy form geothermal
sources.
2. Emits Hydrogen sulfide, which is a toxic gas that produces a rotten egg odor,
produces excessive salt and mineral buildup in pipes that must be removed, lack
of adequate water to produce steam in some areas. Conditions where water is
able to circulate to the surface due to heat is found on only 10% of the Earth’s
surface.
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Nuclear Energy – energy in the nucleus of an atom that can be used to generate
electricity.
1. energy is released by nuclear reactions or radioactive decay. Once the bonds
that hold atoms together in the nucleus are broken an enormous amount of
energy is released. This is done by nuclear fission. As of 2006 nuclear energy
accounts for 19% of total electricity generated in the United States. There are
about 66 million power plants in the United States.
A. nuclear fission – atoms are split apart to form small atoms releasing energy to
produce electricity.
2. Two types of nuclear reactors are used to generate electricity burner reactors
and breeder reactors.
Burner Reactors
1. Uranium 235 is the fuel used for nuclear fission. Fission takes place inside a
reactor vessel, which is made up of steel walls 15 to 30 cm thick to prevent
radiation form escaping. The reactor is contained inside a thick concrete
container.
2. At the center of the reactor is the core, which contains long rods filled with
ceramic uranium pellets submerged in water. Water acts as a coolant and slows
down the chain reaction so uranium can split. Control rods made up of cadmium
and Boron are also placed in the reactor. Control rods absorb neutrons these
rods can be raised or lowered in the reactor to slow down are speed up the
reaction.
3. Uranium is a non-renewable resource but is a common metal found in mined
rocks. The U-235 atoms can easily split apart. During the fission process
neutrons split the Uranium atoms causing heat and radiation to be released.
More neutrons are also released creating a chain reaction, which can be slowed
down or sped up by raising or lowering controlling rods.
4. The energy released from the reaction heats water, which is turned to steam and
drives turbines that spin a generator to produce electricity. In some reactors
steam is generated form a secondary water reservoir so radioactive water never
comes in contact with the turbine. Water in the reactor is heated then circulated
to a secondary water reservoir, where stored water is then heated by conduction.
Water is then circulated back to their original point of origin.
Breeder Reactors
1. Of the Uranium mined today a majority is Uranium-238, which is too stable.
Breeder reactors use very little U-235 to start the fission process. Space
neutrons are captured by U-238, when this happens Plutonium-239 is formed,
which is fissionable and can be split by neutrons.
2. After a chain reaction of Pu-239 is produced U-235 is no longer needed. The
process of generating electricity is similar to a burner reactor but instead uses
liquid Sodium is used in the reactor core as a coolant to keep the chain reaction
going.
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Advantages and Disadvantages of Nuclear Power
1. Large amount of energy avaible, shift to nuclear could reduce fossil fuels and
dependence on foreign oil, does not contribute greenhouse gases, smoke, or
ashes.
2. Mining Uranium is not a clean process and could deplete our Uranium reserves,
Cooling towers dissipate heat into the atmosphere and local water bodies called
Thermal Pollution, breeder reactors could be used by terrorist groups to make
nuclear weapons, Increase in radioactive waste produced.
REVIEW/SUMMARY. Use the student learning objectives as the basis for review and
summary.
APPLICATION. Students will research how to convert their current home or example
home to a solar power home. Each student will be required to find out the amount of
kilowatts and the impact on a monthly electric bill. This information will plug into the
Find Solar web site, www.findsolar.com. Students will be able to determine if
conversion is economical and environmental impact of using solar power. Research will
be compared/contrasted and debated in class, to determine feasibility.
(PS-H-F2), (D-9-H)
EVALUATION. See sample test.
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Answers To Sample Test
Fill in the blank
1. hydroelectric
2. horizontal and vertical
3. biofuels
4. geothermal energy
5. nuclear
Multiple choice
6. A
7. C
8. D
9. A
10. C
11. B
12. A
13. A
14. A
Discussion
15,16,&17 Answer to be determined by teacher evaluation of question.
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SAMPLE TEST:
Student Name:___________________
Date: _______
Fill in the blank:
1. _________________ is electricity produced from the kinetic energy of moving water.
2. Two types of aero generators are _______________ and ____________ axis.
3. ________________ , fuels formed from living or recent living organisms.
4. __________________________________ heat energy generated within the earth.
5. ___________________________ energy is the nucleus of an atom that can be used
to generate electricity.
Multiple choices:
6. Energy from the sun absorbed by the earth and used by all organisms.
a. solar
b. hydroeclectric
c. wind
d. nuclear
7. The only solar devises that produce electricity?
a. active
b. passive
c. photovoltaic
d. hydroelectric
8. For generators to work effectively, wind speeds must be at least how many miles per
hour?
a. 5
b. 10
c. 1
d. 14
9. E-85 means?
a. 85% ethanol & 15% water.
b. 85% ethanol & 15% gas.
c. 8% ethanol & 5% gas.
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10. Sites where many aero-generators are located together in areas of favorable wind
generators.
a. wind mills.
b. wind sites.
c. wind farms.
d. electric stations.
11. Hydrocarbon that is the main component of natural gas that can be collected for
heat?
a. hydrogen
b. methane
c. oxygen
d. nitrogens
Read the following paragraph and answer the questions
Farming is one the leading industries in the US and it has been one the longest lasting
forms of income, and for sustaining life in the history of the US. Without farmers, without
their hard work day after day, many millions of Americans would starve without the
needed nutritious types of products that farmers provide each of us. Farmers use
machinery to cut the hay, to cut the corn, to aid in ways that were never possible before.
One can now run a farm with fewer workers and labor because of the use of automated
machines, and machinery in cutting the crops, moving the crops and even in storing
crops. With all the machinery that is being used by a farmer, the costs of gasoline and
diesel can weight heavily on the farmers bottom line.
Incentives for farmers to use alternative fuels are increasing. The cost of diesel and of
gasoline is constantly on the rise, and the bottom line for the farmer is shrinking as the
gasoline is rising. To combat this, many farmers are striking back, creating their own fuels and
finding alternatives for the gasoline and diesel they would other wise be purchasing. For every
farmer, there is a need to create a better alternative, and farmers are turning to their own
crops, and waste to provide their selves with the needed fuel to cut costs.
http://www.ezilon.com/articles/articles/11/1/Farming-and-alternative-fuels
12. Which of the following statements would best summarize the intent of the passage?
a. Alternative fuels can help our farmers offset the rising cost of fuel
b. An individual U.S. farmer does not need a large workforce to maintain his or
her operation.
c. Alternative fuels are of no benefit for the U.S. farmer
d. Alternative fuels are a waste of valuable research and time.
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13. Which of the following statements would support best support the need for
alternative fuel use?
a. Rising fuel prices and the increase in fuel consumption has put a strange on the
economy, causing consumers to look at alternative fuels.
b. Farmers are not affected by the rise of fuel cost due to tax breaks
c. Alternative fuels could decrease the need for fossil fuels and stimulate jobs in
Local communities.
d. None of the following support alternative fuels
14. Which of the following conclusions is probably correct?
a. One of the oldest professions is being affected economically by the rising cost of
fuel.
b. The American farmer can self sustain his or herself with depending on other
citizens in all professions are not always affected by rising fuel cost or fuel
consumption.
d. All of the above
Discussion: Answer the following questions in the space provided below.
15. Of all the energy sources discussed give at least five (5) advantages and
disadvantages of each alternative source.
16. Explain how alternative sources of energy can benefit the field of agriculture.
17. Which of the alternative energy sources would benefit our geographic area and
what would be the environmental and economic impact is to the local community?
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