Need Energy? Why Not Shoot for the Moon?
The Moon as a Source for Nuclear Fusion and Tidal Generation
Kenneth O’Rourke
MISEP II
August 2008
1
Table of contents
1) Overview --------------------------------------------------------------------------------------- 3
2) Content ---------------------------------------------------------------------------------------- 5
a) Introduction ------------------------------------------------------------------------------- 5
b) Mechanical energy ---------------------------------------------------------------------- 6
c) Nuclear energy --------------------------------------------------------------------------- 7
i) Fission ------------------------------------------------------------------------------- 8
ii) Fusion --------------------------------------------------------------------------------- 9
d) Moon ------------------------------------------------------------------------------------ 16
i) Geology ------------------------------------------------------------------------------ 16
ii) Tides --------------------------------------------------------------------------------- 17
(1) Tidal barrage ------------------------------------------------------------------- 19
(2) Tidal lagoons ------------------------------------------------------------------ 23
(3) Tidal energy is like wind energy --------------------------------------------- 24
e) References ------------------------------------------------------------------------------- 26
3) Pedagogy ------------------------------------------------------------------------------------- 30
a) Unit description ------------------------------------------------------------------------- 31
b) Misconceptions --------------------------------------------------------------------------- 31
c) Understanding by design ---------------------------------------------------------------- 33
i) Stage one: Identifying Desired Results ------------------------------------------- 33
(1) Enduring understandings, Essential questions, Learning outcomes ----- 34
(2) Standards ------------------------------------------------------------------------- 35
(3) Unit objectives ------------------------------------------------------------------ 37
ii) Stage two: Assessment Evidence -------------------------------------------------- 37
iii) Stage three: The Learning Plan --------------------------------------------------- 39
(1) Lesson five: Fully developed lesson ------------------------------------------ 42
iv) Resources ---------------------------------------------------------------------------- 47
v) Appendix ------------------------------------------------------------------------------ 48
vi) References ---------------------------------------------------------------------------- 57
2
Overview
I have always been drawn to figure out why and how things worked. This naturally led
me into a love of science. How does the universe work is the ultimate question. In order
to begin to understand how and why everything works the way it does, energy is the most
important topic be investigated. Energy is the common thread that ties all of the physical
sciences together. I am still amazed at the beauty of Newton’s Laws and the Law of
Conservation of Energy. No matter how many times I teach or read about them, I am
stunned at their sublime beauty. My amazement only grew when I investigated
Einstein’s Theories of Special Relativity and General Relativity. This feeling of awe and
appreciation of science is one attribute I wish to pass on to my students. Even though the
content piece of this project is on energy, it was first germinated in the Earth and Space
rotation of this program. I remember sitting in class learning about the tides in Jane
Dmochowski’s class and thinking about the immense amounts of energy that it takes to
move oceans. I knew that the energy was there for the taking, if we could find an
economical way of harnessing it. As I researched a little deeper into tidal power and
other sources of alternative energy, I came across an article by Harrison Schmidt. He
was the second to last human, and the only geologist to walk on the Moon. The article
detailed that the Moon could be mined for helium-3 for nuclear fusion reactors. I began
thinking that meeting the energy needs of the future could be intimately tied to the Moon,
and my capstone topic was born.
The content section of this project details why and how the Moon could help meet the
energy needs of the world. It starts with a discussion of the basics of how power from
nuclear sources operates. It details why and how the Moon is a potential source for clean
and environmentally friendly nuclear fusion. (It is estimated that one shuttle full of
helium-3 would be enough to meet the United State’s energy needs for a full year. If that
sounds exciting, be sure to read on!) It then details how the energy from the tides can
and is being used to bring clean energy to the public.
3
The pedagogy section of this project focuses on alternative energy with the students
being guided into considering the Moon as a source for alternate gravitational energy and
a source of fuel for nuclear fusion. By introducing my students to this fascinating topic
that has real implications to the world today, I believe that the awe and wonder I feel will
be transmitted to my students. Much of nuclear physics content is significantly above the
grade level of my students, but a basic understanding of the reactions and how the
reactors work is not. The pedagogy piece of this project is focused on higher order
thinking skills of analysis and synthesis of energy in general, and not on a detailed
understanding of nuclear physics. Students will need to evaluate the information to come
up with logical solutions for meeting our future energy needs.
Acknowledgements:
I would like to thank Dr. Barbara Riebling and Dr. Jane Dmochowski of the University of
Pennsylvania and Kathleen Tait of the J. R. Masterman Laboratory and Demonstration
School for all of their contributions, dedication, and patience to this paper. I would also
like to thank my family for their unwavering support through the program. I have been
enthralled, excited, and motivated by all of the instructors in the MISEP program, and
they have inspired me to learn all I could. I humbly thank you all and I aspire to someday
reach your level of knowledge and wisdom.
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Content Section
Need Energy? Why not shoot for the Moon?: The Moon as a source for
nuclear fusion and tidal generation.
Introduction
Energy: What is it, and why don’t we have enough
Energy in its simplest definition is the ability to do work. What exactly is “work”? Work
is the application of force over a distance. The resulting unit for energy is the joule,
which is equal to kgm2/s2. The more energy you have, the larger the force you can apply
or a larger distance you can apply a smaller force. The Law of Conservation of Energy
states that energy cannot be created or destroyed, but energy is changed from one form
into another. The energy problem that the world faces is not that there is not enough
energy, but that it is difficult to harness into useful energy for human consumption.
Other than the chemical energy from food used to maintain homeostasis, the dominant
forms of energy that humans use are electrical energy and chemical energy, in the form of
fossil fuels in the combustion engine and combustion for heat. Electrical energy can also
be used to generate heat and propel machines. Even though electrical energy is widely
used, it is not a resource and must be converted from other sources of energy. The main
source for electricity generation is fossil fuels, a nonrenewable resource.
We need to develop energy supplies that will meet the needs of an ever-growing world
population. For the purposes of this paper the two forms of energy most relevant are
mechanical energy and nuclear energy. (One of the most effective ways to harness these
forms of energy into a usable form is through electricity generation.) The Moon may be
an abundant source for both forms. The enormous amount of energy stored in the
movement of the tides can be transformed into electrical energy with no greenhouse gas
emissions, and the surface of the Moon may be the most promising source for mining
helium-3, a nuclear fuel that may make nuclear fusion generators a reality.
5
How many gallons of water can an average person lift? The more gallons lifted, the more
energy expended to lift them. Expand this idea to how much energy is involved in
moving the oceans and one realizes the enormous energy potential of our oceans. The
gravitational attraction between the Earth and the Moon is the engine that drives the tides,
making them an extremely predictable source of energy.
The question is how to
transform the energy stored in the oceans into usable energy.
Since the 1950’s, scientists have hailed nuclear fusion reactors as the cure for our energy
needs: a source of energy with no adverse environmental side effects. Still it is not a
reality. To date no viable, sustainable nuclear fusion reactor has been developed. Some
of the latest research shows that nuclear fusion would be practical and sustainable if we
had enough of a certain isotope of helium, helium-3. Most of the research has focused on
hydrogen fusion, but a certain level of radiation and an abundance of neutrons are
produced. The neutrons are problematic in they are hard to contain and are destructive to
the walls of the reactors. The benefit of 3He is that neutron emissions are low and no
harmful radiation is produced.
The problem is that helium-3 is not found in any
abundance on the Earth. The Moon on the other hand is an abundant source for this
nuclear fuel, just as it is the source for moving the tides. One of the paths to energy
independence might be through the Moon. By converting the energy of the moon stored
in the tides, and mining helium-3 on the Moon to fuel nuclear fusion reactors, the Earth’s
energy needs could be met without many of the current harmful effects.
Mechanical Energy
Mechanical energy can be separated into two forms: Potential energy and kinetic energy.
They are two sides of the same coin. Potential energy is stored energy or the energy of
position and kinetic energy is the energy of motion. With regard to mechanical energy,
when potential energy decreases, kinetic energy increases by an equal amount. One of
the best applications of potential to kinetic energy transformations comes from the
transformation of gravitational potential energy into kinetic energy. A rock at a height
has potential energy. As it falls, it loses potential energy and gains an equal amount of
kinetic energy. This gravitational potential energy is harnessed when the potential energy
6
of falling water is converted into the kinetic energy of the running water force a wheel to
turn (a water wheel). That turning wheel when connected to large coils of wire in a
magnetic field produces electrical energy. The kinetic energy of the tides ebbing and
flowing can be transformed into electrical energy in a similar way.
Nuclear Energy
Nuclear energy can also be separated into 2 separate forms: nuclear fission and nuclear
fusion. Nuclear fusion is the splitting of large atomic nuclei into smaller elements
releasing energy, and nuclear fusion is the joining of two small atomic nuclei into a larger
element and in the process releasing energy. The mass of a nucleus is always less than
the sum of the individual masses of the protons and neutrons which constitute it. The
difference is a measure of the nuclear binding energy which holds the nucleus together
(Figure 1). As figures 1 and 2 below show, the energy yield from nuclear fusion is much
greater than nuclear fission.
Figure 1
Nuclear binding energy = ∆mc2
For the alpha particle ∆m= 0.0304 u which gives a binding energy of 28.3 MeV.
(Figure from: http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html)
7
Fission and fusion can yield energy
Figure 2
(Figure from: http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html)
Nuclear fission
When a neutron is fired at a uranium-235 nucleus, the nucleus captures the neutron. It
then splits into two lighter elements and throws off two or three new neutrons (the
number of ejected neutrons depends on how the U-235 atom happens to split). The two
new atoms then emit gamma radiation as they settle into their new states. (John R.
Huizenga, "Nuclear
fission", in
AccessScience@McGraw-Hill,
http://proxy.library.upenn.edu:3725) There are three things about this induced fission
process that make it especially interesting:
1)
The probability of a U-235 atom capturing a neutron as it passes by is fairly
high. In a reactor working properly (known as the critical state), one neutron
ejected from each fission causes another fission to occur. (Huizenga)
2)
The process of capturing the neutron and splitting happens very quickly, on the
order of picoseconds (1x10-12 seconds). (Huizenga)
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3)
An incredible amount of energy is released, in the form of heat and gamma
radiation, when a single atom splits. The two atoms that result from the fission
later release beta radiation and gamma radiation of their own as well. The
energy released by a single fission comes from the fact that the fission
products and the neutrons, together, weigh less than the original U-235 atom.
The difference in weight is converted directly to energy at a rate governed by
the equation E = mc2. Something on the order of 200 MeV (million electron
volts) is released by the decay of one U-235 atom.1That may not seem like
much, but there are a lot of uranium atoms in a pound of uranium. A pound of
highly enriched uranium used to power a nuclear submarine is on the order of
a million gallons of gasoline. (Huizenga)
There are some drawbacks of nuclear fission reactors, namely:
1) Mining and purifying uranium has, historically, been a process that leaves very
toxic byproducts.
2) Improperly functioning nuclear power plants can create big problems. The
Chernobyl disaster is a good recent example that dramatically shows the worstcase scenario.
Chernobyl scattered tons of radioactive dust into the
atmosphere.
3) Spent fuel from nuclear power plants is toxic for centuries, and, as yet, there is
no safe, permanent storage facility for it. Yucca mountain in Nevada is the
future permenant depository when it becomes operational.
4) Transporting nuclear fuel to and from nuclear plants poses some risk, although
to date, the safety record in the United States has been good.
Nuclear Fusion
The sun releases energy through nuclear fusion reactions. The immense temperature and
pressure in the Sun forces hydrogen atoms fuse into deuterium, then the deuterium atom
fuses together with another hydrogen atom to form a tritium atom, and then the tritium
1
1 eV is equal to 1.602 x 10-12 ergs, 1 x 107 ergs is equal to 1 joule, 1 joule equals 1 watt-second, and 1
BTU equals 1,055 joules).
9
atom fuses with another hydrogen atom to from a helium atom. The resulting helium
atom’s mass is less than four hydrogen atoms. The missing mass is transformed into
energy by Einstein’s E=mc2 equation (Figures 1 and 2). The reaction between the nuclei
of the two heavy forms (isotopes) of hydrogen - deuterium (D) and tritium releases 17.6
MeV (2.8 x 1012 joule).
There are currently two types of fusion reactions that are considered the most promising
for nuclear fusion reactors: the deuterium tritium reactor, and the helium-3 deuterium
reactor.
Deuterium tritium reaction
The fusion of deuterium and tritium reaction yields 17.6 MeV of energy but requires a
temperature of approximately 40 million Kelvin to overcome the coulomb barrier and
ignite it. (Post et al., 2005)
Even though a lot of energy is required to overcome the Coulomb barrier and initiate
hydrogen fusion, the energy yields are enough to encourage continued research.
Hydrogen fusion on the earth could make use of the reactions:
(Post et al., 2005)
These reactions are more promising than the proton-proton fusion of the stars for
potential energy sources. Of these the deuterium-tritium fusion appears to be the most
promising and has been the subject of most experiments. In a deuterium-deuterium
reactor, another reaction could also occur, creating a deuterium cycle:
(Post et al., 2005)
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This reaction also releases a neutron. This neutron is difficult to contain due to its nonpolar nature. As a result the walls of the reactor suffer significant damage over a short
time from a constant barrage of neutrons. Current research is continuing in an effort to
contain the neutrons without sustaining reactor damage. (Post et al., 2005)
Helium-3 deuterium reaction
The Major advantages of 3He- deuterium reactions are: 1. a significant reduction of
radiation damage in the form of neutrons to the reactor wall, 2. reduction of avoidance of
radioactivity, 3. higher energy conversion without waste heat (Kolinsky, 2001).
However, there are still some problems.
The reactors need to operate at higher
temperatures than deuterium- tritium reactions, and there is a very limited source of
helium-3 on the surface of the Earth. Helium-3 is a natural part of the solar wind. Our
atmosphere does not allow helium-3 to reach the surface, but the Moon has no
atmosphere and is constantly bombarded by helium-3. (Kolinsky, 2001).
The deuterium and helium-3 atoms come together to give off a proton and helium-4. The
products weigh less than the initial components; the missing mass is converted to energy.
1 kg of helium-3 burned with 0.67 kg of deuterium gives us about 19 megawatt-years of
energy output. The fusion reaction time for the D-3He reaction becomes significant at a
temperature of about 10 KeV, and peaks about about 200 KeV. A 100 KeV reactor
appears to be optimum. (University of Wisconsin, Fusion Technology institute,
http://fti.neep.wisc.edu/presentations/lae_dhe3_icenes07.pdf) A reactor built to use the
D-3He reaction would be inherently safe. The worst-case failure scenario would not
result in any civilian fatalities or significant exposures to radiation. (Kolinsky, 2001).
Inertial Electrostatic Confinement (IEC) and toroidal magnetic field for confining a
plasma (Tokamak)
There are currently 2 methods in which helium-3 has been shown to fuse in a reactor.
One is a high pressure (gravity, and inertial confinement) and high temperature
11
(electrostatic confinement and magnetic confinement) reactor. At the Fusion Technology
institute at the University of Wisconsin-Madison they have developed an Inertial
electrostatic containment device that is the first known fusion of helium-3 with deuterium
on a steady state basis. (Radel, Kulcinsky, Donavan, Detection of HEU Using a Pulsed
D-D Fusion Source, March 2007)
Photo of IEC in action (http://iec.neep.wisc.edu)
The gridded IEC approach possesses the advantage that ions can be continuously
accelerated to high fusion relevant energy with relative ease (tens of KeV). The steady
state burning of advanced fusion fuels such as deuterium- 3He and 3He-3He is a key
feature of IEC devices. The IEC device does not require any magnetic coils for plasma
confinement, allowing it to be lightweight and portable. Since the reaction does not
utilize deuterium- tritium the problem of neutron activation of the reactor is of far less
significance.
The device is small.
It is an approximately one meter in diameter
aluminum vacuum cylinder that is 65 cm high. (Radel, Kulcinsky, Donavan, Detection
of HEU Using a Pulsed D-D Fusion Source, March 2007)
12
(photo from: http://fti.neep.wisc.edu/ncoe?rm=iec)
(photo from: http://iec.neep.wisc.edu/photopages/GeneralOpPics.htm)
The device produced a steady stream of protons, neutrons, helium-4, tritium, gamma and
x rays. (Radel, Kulcinsky, Donavan, Detection of HEU Using a Pulsed D-D Fusion
Source, March 2007)
Fusion fuel cycles, except He-3-He-3, are not completely aneutronic due to their side
reactions. Neutron wall loadings can be kept low (by orders of magnitude) compared to
13
D-T fuelled plants with the same output power, eliminating the need for a breeding
blanket 2and the replacement of the first wall and shielding components during the entire
plant lifetime.
The availability of He-3 and the attainment of the higher plasma
parameters required for burning are challenging problems for the D-He-3 fuel cycle.
High beta and/or high field innovative confinement concepts, such as the field-reversed
configuration and, to a lesser extent, the TOKAMAKks are suitable devices for advanced
fuel cycles. In the early 1990s, the ARIES-III D-He-3 TOKAMAK was developed within
the framework of the ARIES study. (The ARIES program is a national, multi-institutional
research activity. (Guebal et al, 2007).
(ARIES III TOKAMAK from: http://fti.neep.wisc.edu/ncoe?rm=dhe3)
Its mission is to perform advanced integrated design studies of the long-term fusion
energy embodiments to identify key research and development directions and to provide
visions for the fusion program. It is funded by the Office of Fusion Energy Sciences,
U.S. Department of Energy.) The UW D-He-3 Apollo series, along with ARIES-III,
demonstrated attractive safety characteristics, including low activity and decay heat
levels, low-level waste, and low releasable radioactive inventory from credible accidents.
Another advantage for the D-He-3 system is the possibility of obtaining electrical power
by direct energy conversion of the protons and radiation produced by fusion reactions.
2
Protect the magnets and the vacuum vessel from neutron and gamma radiation, produce the tritium necessary for continued fusion reactions,
convert neutron energy into heat and evacuate it to generate a cycle capable of supplying electricity.
14
The nuclear fusion reaction can only be self-sustaining if the rate of loss of energy from
the reacting fuel is not greater than the rate of energy generation by fusion reactions. The
simplest consequence of this fact is that there will exist critical or ideal ignition
temperatures below which a reaction could not sustain itself, even under idealized
conditions. In a fusion reactor, ideal or minimum critical temperatures are determined by
the unavoidable escape of radiation from the plasma. A minimum value for the radiation
emitted from any plasma is that emitted by a pure hydrogenic plasma in the form of xrays or bremsstrahlung. (Charged particles moving through matter will lose energy by
emitting a photon, or interacting with the matter causing it to lose energy.) Thus plasmas
composed only of isotopes of hydrogen and their one-for-one accompanying electrons
might be expected to possess the lowest ideal ignition temperatures. In fact, it can be
shown by comparison of the nuclear energy release rates with the radiation losses that the
critical temperature for the D-T reaction is about 4 × 107 K. For the D-D reaction it is
about 10 times higher. Since both radiation rate and nuclear power vary with the square
of the particle density, these critical temperatures are independent of density over the
density ranges of interest. The concept of the critical temperature is a highly idealized
one, since in any real cases additional losses must be expected to occur which will
modify the situation, increasing the required temperature. (Richard F. Post, Allen H.
Boozer, Eric
Storm, Bogdan
Maglich, James
S.
Cohen, "Nuclear
fusion", in
AccessScience@McGraw-Hill, http://proxy.library.upenn.edu:3725, DOI 10.1036/10978542.458800)
The absence of neutrons and radioactivity removes the need for shielding. This is
particularly significant for aero-space applications, since the weight of shielding in a
(Post et al., 2005)
An aneutronic reactor
3
also offers the advantages of non-radioactive fuel and non-
radioactive waste. Since all nuclear energy released in aneutronic reactions is carried by
3
Aneutronic fusion is any form of fusion power where no more than 1% of the total energy released is carried by neutrons.
15
charged particles, if these particles could be directed into a beam a flow of electric charge
would result, and nuclear energy could be converted directly into electrical energy, with
no waste heat. (B. Maglich and J. Norwood (eds.), Proceedings of the 1st International
Symposium on Feasibility of Aneutronic Power, Nucl. Instrum. Meth., A271:1–240,
1988)
An aneutronic reactor could be small, producing 1–100 MW of electric power, and mass
production might be possible. Aneutronic reactors cannot breed plutonium for nuclear
weapons. (B. Maglich and J. Norwood (eds.), Proceedings of the 1st International
Symposium on Feasibility of Aneutronic Power, Nucl. Instrum. Meth., A271:1–240,
1988)
The only practical source for helium-3 and a viable commercial aneutronic reactor is the
Moon.
Moon
To understand how the Moon factors into the energy sources discussed in the previous
section, one must first understand the Moon’s geology.
Geology
The lunar landings gave scientists the opprotunity to directly test rocks from the Moon.
Engineers at the University of Wisconsin predicted that Lunar samples should contain
helium-3 as a result of interaction from the solar wind. Lunar samples were tested and
were found to contain helium-3 (Schmidt 2004).
There is a particularly strong
correlation between helium-3 content and titanium oxide content of the lunar rock
(Wittenberg, Camerson, et al, 2001). Samples collected in 1969 by Neil Armstrong
during the first lunar landing showed that helium-3 concentrations in lunar soil are at
least 13 parts per billion (ppb) by weight. Levels may range from 20 to 30 ppb in
undisturbed soils. The Moon contains vast stores of helium-3, locked up most efficiently
in deposits of titanium. The titanium containing rocks found on the Moon's surface, acts
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like a sponge, soaking up the particles of helium-3 driven through space by the solar
wind. The solar wind cannot deposit helium-3 on the Earth, since the Earth’s atmosphere
protects the surface from solar wind. During the 4 billion years since the Moon was
formed, the titanium reserves have absorbed around a million tonns of helium-3. Almost
all of it is in the top 3 metres of soil in low-lying areas on the near side of the Moon.
(Sviatoslavsky, I. N., Processes and Energy Costs for Mining lunar Helium-3, Wisconsin
Univ., Madison, In NASA, Lewis Research Center, Lunar Helium-3 and Fusion Power p
129-146 (SEE N89-14842 06-75) Because the concentration of helium-3 in the rocks is
relatively low compared to the mass of the rock, if lunar rock were to be used as a source
of energy for nuclear reactors on Earth, it would be necessary to process large amounts of
rock and soil to isolate the material. Digging a patch of lunar surface roughly threequarters of a square mile to a depth of about 9 ft. should yield about 220 pounds of
helium-3 (Schmidt 2004). In 1986, John Santarius, a physicist at the University of
Wisconsin- Madison, proposed mining the titanium-rich soil with a robotic digger and
removing the helium-3 by heating it to 700 degrees C with the Sun's rays focused by an
orbiting mirror. At this temperature, more than 85 per cent of the helium-3 would boil
off along with other gases such as oxygen, hydrogen, nitrogen and carbon dioxide. These
could be separated by cooling the mixture until only helium remained a gas, a process
that would be relatively easy during the lunar night when temperatures plummet to -100
degrees C. While the other gases might prove useful for human colonists, the helium
could be transported to Earth. It is estimated that eventually the cost of lunar fusion fuel
would fall as low as $100,000 per kilogram - the US currently charges $700,000 for the
same amount of its helium-3 (Sviatoslavsky)
The prospects for Helium-3 are very promising, but will do little to help in the next few
years. But the Moon can be a major contributor to our energy crisis solutions in the near
term as well.
Earth’s Gravitational Attraction to the Moon and the Resulting Tides
The revolution and rotation of the Moon are well understood and there is little debate as
to their mechanisms in the present day. However, it is generally unknown to the public
17
that the Moon is responsible for the current length of our day. Research in the early part
of the 20th century found that the Moon was much closer in the past and is getting farther
everyday (Street, 1917). More current investigations found the Moon to have a drag
effect on the Earth, causing our days to go from 18 hours long to the current 24 hours.
While the Moon orbits the Earth, it will continue to lengthen our days (Brosche, 1984).
There is also evidence that if it were not for the Moon, the Earth’s tilt would be much
more variable (one model suggests it would change from eleven to forty degrees)
(Peterson, 1993). This would have had a tremendous impact for life on Earth. With the
Earth’s tilt varying, the Earth’s climate would be much more erratic, making it difficult
for more complex life forms to develop.
The biggest influence that the Moon has on the Earth on a daily basis is the tides. This
interaction has been understood on a gross scale according to Newton’s laws for a very
long time (Schneider, 1880). The Sun also plays a role in the Earth’s tides. Although the
Sun is much larger than the Moon, it is also much further away. The importance of
distance becomes obvious when you examine Newton’s law of universal gravitation. The
strength of gravity decreases with the square of the distance proportional to the product of
the two masses. A more sophisticated description of how the Moon influences the tides
involves a gravitational gradient. (Trujillo, Thurman, Essentials of Oceanography,
Pearson Prentice Hall, 2005) Because the Moon is much closer the gravitational gradient
between the far and near side of the moon is more significant than the gradient between
the near and far side of the sun.
This results in the lunar force being inversely
proportional to the cube of the distance, thereby causing the Moon to have a greater
influence on the tides on Earth. The Sun’s influence is felt as constructive or destructive
to the Moon’s influence based on the geometrical relationship between the forces of the
Earth, Moon, Sun system. When the geometrical relationship is parallel, as in the Full
Moon and New Moon, the forces are additative and the Earth has the highest tides. When
the geographical relationship is at right angles between the Sun and the Moon, The Sun’s
influence mitigates the Moon’s influence and the tides are at their lowest. (Trujillo,
Thurman, Essentials of Oceanography, Pearson Prentice Hall, 2005)
18
The Moon pulls on Earth’s ocean nearest the Moon and causes a bulge. On the opposite
side of the Earth, the bulge is caused by the moon pulling on the Earth’s center of mass
more than it pulls the ocean on the opposite side of the Earth, essentially resulting in the
Earth being pulled out from under the water and creating a second high tide each day.
Some of the other factors that influence the tides are the shapes of the coastline, depth of
the water, and the deformation of the ocean basin (Farrel, 1973). These effects are
demonstrated by the unusually large tidal range in the Bay of Fundy. The effects of the
Moon on the tides is not only on seas and oceans, but on groundwater as well; studies on
groundwater over the course of months show that the average groundwater levels also
fluctuate with the tides (Schureman, 1926).
How is tidal energy harnessed?
There are two different approaches to the exploitation of tidal energy. The first is to
harness the cyclic rise and fall of the sea level through entrainment and the second is to
harness local tidal currents in a manner somewhat analogous to wind power.
Tidal Barrage Methods
There are many places in the world in which local geography results in particularly large
19
tidal ranges. Sites of particular interest include the Bay of Fundy in Canada, which has a
mean tidal range of 10 m, the Severn Estuary between England and Wales, with a mean
tidal range of 8 m and Northern France with a mean range of 7 m. A tidal-barrage power
plant has been operating at La Rance in Brittany since 1966 (Banal and Bichon, 1981).
This plant, which is capable of generating 240 MW, incorporates a road crossing of the
estuary. It has recently undergone a major ten-year refurbishment program
.
Photos and diagrams from: http://www.reuk.co.uk/Severn-Barrage-Tidal-Power.htm
20
Other operational barrage sites are at Annapolis Royal in Nova Scotia (18 MW), the Bay
of Kislaya, near Murmansk (400 kW) and at Jangxia Creek in the East China Sea (500
kW) (Boyle, 1996). Schemes have been proposed for the Bay of Fundy and for the
Severn Estuary but have never been built.
Principles of Operation.
On a fundamental level, the principles of operation are always the same. An estuary or
bay with a large natural tidal range is identified and then artificially enclosed with a
barrier. This would typically also provide a road or rail crossing of the gap in order to
maximise the economic benefit. The electrical energy is produced by allowing water to
flow from one side of the barrage, through low-head turbines, to generate electricity.
There are a variety of suggested modes of operation. These can be broken down initially
into single-basin schemes and multiple-basin schemes. The simplest of these are the
single-basin schemes.
Single-Basin Tidal Barrage Schemes
These schemes require a single barrage across the estuary. There are three different
methods of generating electricity with a single basin. All of the options involve a
combination of sluices which, when open, can allow water to flow relatively freely
through the barrage, and gated turbines, the gates of which can be opened to allow water
to flow through the turbines to generate electricity. (Survey of Energy Resources, World
Energy Council, Harnessing the Energy in Tides, 2007)
Ebb Generation Mode
During the flood tide, incoming water is allowed to flow freely through sluices in the
21
barrage. At high tide, the sluices are closed and water retained behind the barrage. When
the water outside the barrage has fallen sufficiently to establish a substantial head
between the basin and the open water, the basin water is allowed to flow out though lowhead turbines and to generate electricity.
The system can be considered as a series of phases. Typically the water will only be
allowed to flow through the turbines once the head is approximately half the tidal range.
This method will generate electricity for, at most, 40% of the tidal range. (Survey of
Energy Resources, World Energy Council, Harnessing the Energy in Tides, 2007)
Flood Generation Mode
The sluices and turbine gates are kept closed during the flood tide to allow the water level
to build up outside the barrage. As with ebb generation, once a sufficient head has been
established the turbine gates are opened and water can flow into the basin, generating
electricity. This approach is generally viewed as less favourable than the ebb method, as
keeping a tidal basin at low tide for extended periods could have detrimental effects on
the environment and on shipping. In addition, the energy produced would be less, as the
surface area of a basin would be larger at high tide than at low tide, which would result in
rapid reductions in the head during the early stages in the generating cycle. (Survey of
Energy Resources, World Energy Council, Harnessing the Energy in Tides, 2007)
Two-Way Generation
It is possible, in principle, to generate electricity during both ebb and flood currents.
Computer models do not indicate that there would be a major increase in the energy
production.
In addition, there would be additional expenses associated in having a
requirement for either two-way turbines or a double set to handle the two-way flow.
Advantages include, however, a reduced period with no generation and the peak power
would be lower, allowing a reduction in the cost of the generators. (Survey of Energy
Resources, World Energy Council, Harnessing the Energy in Tides, 2007)
22
Double-Basin Systems
All single-basin systems suffer from the disadvantage that they only deliver energy
during part of the tidal cycle and cannot adjust their delivery period to match the
requirements of consumers.
Double-basin systems have been proposed to allow an
element of storage and to give time control over power output levels. The main basin
would behave essentially like an ebb generation single-basin system. A proportion of the
electricity generated during the ebb phase would be used to pump water to and from the
second basin to ensure that there would always be a generation capability.
It is anticipated that multiple-basin systems are unlikely to become popular, as the
efficiency of low-head turbines is likely to be too low to enable effective economic
storage of energy. The overall efficiency of such low-head storage, in terms of energy
out and energy in, is unlikely to exceed 30%. It is more likely that conventional pumpedstorage systems will be utilized. The overall efficiency of these systems can exceed 70%
which is likely to prove more financially attractive. (Survey of Energy Resources, World
Energy Council, Harnessing the Energy in Tides, 2007)
Tidal lagoons
Tidal barrage systems are likely to cause substantial environmental change; ebb
generation results in estuarial tidal flats being covered longer than in a natural estuary.
Electricity would be generated using sluices and gated turbines in the same manner as
conventional' barrage schemes. The principal advantage of a tidal lagoon is that the
coastline, including the intertidal zone, would be largely unaffected. Careful design of the
lagoon could also ensure that shipping routes would be unaffected. A much longer
barrage would, however, be required for the same surface area of entrainment. Some
preliminary studies do suggest that in suitable locations, the costs might be competitive
with other sources of renewable energy. There has not yet been any in-depth, peer-
23
reviewed assessment of the tidal lagoon concept, so estimates of economics, energy
potential and environmental impact should be treated with caution
In
2000
a
large
vertical-axis
floating
device
(the
Enermar
project
[www.pontediarchimede.com]) was tested in the Strait of Messina between Sicily and the
Italian mainland. Marine Current Turbines Ltd (www.marineturbines.com) of Bristol,
England, has been demonstrating a large pillar-mounted prototype system called Seaflow
in the Bristol Channel between England and Wales. It is intended that the same company
will install a further large prototype system, SeaGen, in Strangford Narrows in Northern
Ireland, probably in late-summer 2007. Although conceptually similar to Seaflow, it
would be equipped with two rotors and have a rated capacity of 1.2MW.
In Norway, the Hammerfest Strøm system (www.tidevannsenergi.com) demonstrated that
pillar-mounted horizontal-axis systems can operate in a fjord environment. In the USA
the first of an array of tidal turbines were installed in December 2006 in New York's East
River (www.verdantpower.com ). Once fully operational this should be the world's first
installed array of tidal devices.
In 2007, The European Marine Energy Centre (EMEC) (www.emec.org.uk), which was
established in 2004 to allow the testing of full-scale marine energy technology in a robust
and transparent manner, became fully equipped for the testing of tidal, as well as wave
energy, technology. The tidal test berths are located off the south-western tip of the
island of Eday, in an area known as the Fall of Warness.
The facility offers five tidal test berths at depths ranging from 25 m to 50 m in an area 2
km across and approximately 3.5 km in length.
Each berth has a dedicated cable
connecting back to the local grid. The first tidal device (www.openhydro.com) was
installed at the end of 2006. This is operated by the OpenHydro Group and is a novel
annular-turbine system held by twin vertical pillars.
Tidal power is like wind power
24
The physics of the conversion of energy from tidal currents is superficially very similar to
the conversion of kinetic energy in the wind. Many of the proposed devices have
therefore an inevitable resemblance to wind turbines. There is no total agreement on the
form and geometry of the conversion technology itself. Wind-power systems are almost
entirely horizontal-axis rotating turbines. In these systems the axis of rotation is parallel
to the direction of the current flow. Many developers favour this geometry for tidal
conversion. Vertical-axis systems, in which the axis of rotation is perpendicular to the
direction of current flow, have not been rejected. It is of interest to note that Enermar
used a novel Kobold vertical-axis turbine.
The environmental drag forces on any tidal-current energy-conversion system are very
large, when compared with wind turbines of the same capacity. This poses additional
challenges to the designer. Designs exist for devices which are rigidly attached to the
seabed or are suspended from floating barges, such as the early Loch Linnhe device. It is
generally accepted that fixed systems will be most applicable to shallow-water sites and
moored systems for deep water.
Although prototype tidal-current devices are now available and have mostly proved
successful in their operation, there are still issues requiring resolution before the resource
can be fully exploited. With the exception of the New York East River development,
knowledge of the performance of devices in arrays is somewhat limited, although
theoretical models are at last becoming available. It is also becoming obvious that
turbulence levels in high-energy tidal flows can be considerable. Turbulent amplitudes
exceeding 30% of the time-averaged flows have been measured and this will prove
challenging to systems designers. There is an ongoing need for enhanced understanding
of the behaviour of tidal-current devices in the presence of incident waves. These gaps in
understanding should not prevent ongoing deployment of pre-commercial, or even earlystage commercial technology, provided that technology developers are aware of the
design constraints that knowledge gaps impose and recognise that they themselves are
part of the research process. This will ultimately allow efficient technology development
and hence allow cost-effective exploitation of the tidal-current resource.
25
Conclusion: If we have the will, the benefits could be out of this world.
Two of the fundamental criteria of an energy solution are that it must be clean and
sustainable. The two methods outlined in this project acomplishes both. The short term
energy crisis can be mitigated through the use of the Moon’s gravitational effect on the
Earth, and the Earth’s long term energy goals can be met utilizing the Moon as a mineral
resource. The energy used to generate the tides is available for human consumption
today, and will be a predictable energy supply as long as the Moon orbits the Earth. We
just need to transform it into useful energy for our needs. The technology is available.
Using it is a matter of will and economics. The Utilization of the Moon as a resource for
helium-3 is not, at present time, feasable. Until He-3 reactors demonstrate a reliable
positive energy gain, the mining operations on the Moon will not happen. The research is
very encouraging and shows significant improvement over the past decade.
References
1) Huizenga, J. R., "Nuclear fission", in AccessScience@McGraw-Hill, (2005)
http://proxy.library.upenn.edu:3725, DOI 10.1036/1097-8542.458400
2) Boozer, A. H., Cohen, J. S., Post, R. F., Maglich, B., Storm, E., "Nuclear
fusion", in
AccessScience@McGraw-Hill,
(2005)
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3) Camerson, E.N. ; Kulcinski, G.L. ; Ott, S.H. ; Santarius, J.F. ; Sviatoslavsky, G.I.
; Sviatoslavsky, I.N. ; Thompson, H.E.; Wittenberg, L.J.
(Wisconsin Univ.,
Madison, WI (United States). Fusion Technology Inst.) A review of sup 3 He
resources and acquisition for use as fusion fuel, May, 2001
4) Alderson, E., Ashley, R., Boris, D., Donovan, D., Egle, B., Kulcinski, G., Piefer,
G., Radel, R., Santarius, J., Sorebo, J., Zenobia, S., Detection of HEU Using a
Pulsed D-D Fusion Source, March 2007 [presented at the 2007 ANS Student
Conference, Oregon State University, Corvallis OR, 29-31 March 2007]
26
5)
L. El-Guebaly, Henderson, Ibrahim A.,D., Kiedrowski, B.,Sawan, M.,
P.,Slaybaugh, R.,Sviatoslavsky, G., Tautges, T., Wilson, P., and the ARIES
Team, Nuclear Challenges and Progress in Designing Stellarator Power Plants,
June 2007 [presented at the 13th International Conference on Emerging Nuclear
Energy Systems (ICENES 2007), 3-8 June 2007, Istanbul, Turkey]
6) B. Maglich and J. Norwood (eds.), Proceedings of the 1st International
Symposium on Feasibility of Aneutronic Power, Nucl. Instrum. Meth., A271:1–
240, 1988
7) Schmitt, Harrison H. Mining The Moon, Popular Mechanics; Oct2004, Vol. 181
Issue 10, p56-61, 6p, 1 diagram, 3c
8) Sviatoslavsky, I. N., Processes and Energy Costs for Mining lunar Helium-3,
Wisconsin Univ., Madison, In NASA, Lewis Research Center, Lunar Helium-3
and Fusion Power p 129-146 (SEE N89-14842 06-75)
9) Street, R. O. (1917). The Dissipation Energy in the Tides in Connection With the
Acceleration of the Moon’s Mean Motion. Proceedings of the Royal Society of
London. Series A, Containing Papers of a Mathematical and Physical Character,
93 (652) 348-359.
10) Brosche, P., Wolfson, M.M., (1984). Tidal Friction in the Earth-Moon System
[and Discussion]. Philosophical Transactions of the Royal Society of London.
Series A, Mathematical and Physical Sciences, 313 (1524)
11) Peterson, J (1993) Tilted: stable Earth, chaotic Mars - changes in angle of axis
affects
climate
on
planets
Science
News
http://findarticles.com/p/articles/mi_m1200/is_n9_v143/ai_13533907
12) Schneider, E., (1880). On the Phenomena of the Tides. The Analyst, 7 (5) 154157
13) Thurman, H. V., Trujillo, A. P., Essentials of Oceanography, Pearson Prentice
Hall, 2005
27
14) Farrel, W. E. (1973). Earth Tides, Ocean Tides and Tidal Loading. Philosophical
Transactions of the Royal Society of London. Series A, Mathematical and
Physical Sciences, (1239) 253-259.
15) Schureman, P. (1926). Tides in Wells. Geographical Review, 16 (3) 479-483
16) Banal, M. and Bichon A., 1981. Tidal Energy in France, The Rance Tidal Power
Station - some results after 15 years in operation, Proceedings of the Second
International Symposium on Wave and Tidal Energy, Cambridge.
17) Survey of Energy Resources, World Energy Council, Harnessing the Energy in
Tides,
2007
http://www.worldenergy.org/publications/survey_of_energy_resources_2007/tidal
_energy/755.asp
18) Ivich, N., Miley, G.H., Towner, H., Fusion cross sections and reactivities, 1974
Jun 17
19) John P. Holdren, Fusion Energy in Context: Its Fitness for the Long Term.
Science, New Series, Vol. 200, No. 4338 (Apr. 14, 1978), pp. 168-180
20) Ivars Peterson, Sparking Fusion, Science News, Vol. 150, No. 16 (Oct. 19, 1996),
pp. 254-255
21) Michael Guillen, Moon Mines, Space Factories and Colony L5, Science News,
Vol. 110, No. 8 (Aug. 21, 1976), pp. 124-125
22) Kaula, W.M. (1969). The Gravitational Field of the Moon. Science, New Series,
(166) 1581-1588.
23) Brosche, P., Wolfson, M.M., (1984). Tidal Friction in the Earth-Moon System
[and Discussion]. Philosophical Transactions of the Royal Society of London.
Series A, Mathematical and Physical Sciences, 313 (1524)
24) Cameron, E. N., Helium mining on the Moon: Site selection and evaluation, In
NASA. Johnson Space Center, The Second Conference on Lunar Bases and Space
Activities of the 21st Century, Volume 1 p 189-197 (SEE N93-17414 05-91)
28
25) Yoder, C. F., Hutchison, R., (1981). The Free Librations of a dissipative moon
[and Discussion]. Philosophical Transactions of the Royal Society of London.
Series A, Mathematical and Physical Sciences, 303 (1477)
26) Kopal, Z., (1967). The Shape of the Moon, Its Internal Structure and Moments of
Inertia. Proceedings of the Royal Society of London. Series A, Mathematical and
Physical Sciences Vol. 296, No. 1446, (Feb. 7, 1967), pp. 254-265.
27) Street, R. O. (1917). The Dissipation Energy in the Tides in Connection With the
Acceleration of the Moon’s Mean Motion. Proceedings of the Royal Society of
London. Series A, Containing Papers of a Mathematical and Physical Character,
93 (652) 348-359.
28) Lunau, K (2008) Windmills under the sea Maclean’s 121 (16) 46
29
Pedagogy Section
Energy, Energy Everywhere, and Not a Drop to Spare
30
Kenneth O’Rourke
Energy Unit
Energy, energy everywhere, and not a drop to spare
Unit Description
This lesson was designed using the backwards design model illustrated by Wiggins and
McTighe (1998) and influenced by the enduring understandings noted below. It covers
the topic of alternative energy generation. The unit is prefaced by a more mechanical
treatment of energy in the previous lesson. The previous lesson focused on potential and
kinetic mechanical energy, energy transformations between them, efficiency of energy
transformations, and the law of conservation of energy. This lesson focuses on higher
order thinking skills that incorporate the concepts learned in the previous lesson and
apply them to the energy crisis facing the world today. Students need to use their
previous knowledge of energy and incorporate it with alternative energy sources.
Students must then use this knowledge to apply it to current problems in society today,
and propose possible solutions. Students will need to analyze and synthesize new and
previous learning to be successful. Students that make a concrete connection between
how the mechanical energy is transformed from or into other forms of energy and then
into something we can use will leave the lesson an informed citizen able to make
intelligent decisions regarding alternative energy in our democratic society.
Student misconceptions (alternate frameworks)
Student misconceptions in science many times occur when an abstract concept is thought
to have concrete properties. This is natural for students to call on their personal
experience with objects and to base their understanding on how they perceive those
objects to behave (Reiner, Slotta et al). The problem also occurs when scientific
language and colloquial language have different meanings, such as the everyday meaning
of theory as an idea to the scientific concept of theory. Research has shown that students
come to school holding powerful conceptions with explanatory power, but those concepts
31
were inconsistent with scientific concepts presented in school (Smith, diSissa, Roschelle).
A common conceptual misconception would be that heavy things fall faster than light
things. While this is true when air resistance becomes significant, it is not an accurate
description of nature. In many cases, I myself have observed these principles as the
biggest roadblocks to students’ understanding of science. In teaching energy some of the
most powerful misconceptions or alternative understandings of energy are: (Clement J.
1987)
Energy and force are interchangeable terms
Things use up energy
Energy is not conserved because we are running out of it
An object at rest has no energy
Energy is a thing
Energy is only associated with movement
Energy is a fuel
Energy is recycled
Students that have difficulties in breaking away from vernacular language to using a
more scientific language tend to retard the students’ understanding in science (Jones,
Idol). I have found this to be the case in teaching energy. Students routinely think that
energy, force, momentum, and power, all have the same meaning. While students that
make the distinction usually do much better than students that do not, it is important to
try and insure that all students are brought to the point of understanding the terms unique
scientific meaning. Accentuating the differences and making distinctions in compare and
contrast questions is an effective way to bring students to a proficient understanding of
their scientific meaning. Students come to school with a very powerful preconceived
notion of how the world works. When they are confronted with an anomalous situation,
they will often ignore the anomaly, force it to fit their understanding, or think that they
made a mistake in a lab situation. The successful student will change their model to
incorporate the anomaly. While many students become successful by the time the unit
assessment is completed, many will not retain this changed model into their permanent
32
thinking and will revert back to their previous model (Chong L. 2005) I have seen this in
action myself. Many times I have extinguished the idea that heavy objects fall faster than
light objects in the absence of friction, only to have students explain the opposite to me
within a week of the assessment. An effective method is to constantly revisit those
concepts whenever applicable. For example: when discussing potential energy and
kinetic energy revisit the concepts of acceleration under gravity and make predictions as
to the effects of energy because of the uniform acceleration of all objects on Earth. When
getting to a more complex concept such as energy, previous misconceptions that were
thought to have been extinguished surface again. By using the new topic of energy the
concept of uniform acceleration under gravity can be revisited and the correct concept
reinforced. Students misconceptions through erroneously attributing concrete principles
to abstract concepts, and the misinterpretation of scientific meanings of words, makes it
very challenging to reach many students. A good way to intercept those problems is to
identify them early. One effective method for identifying misconceptions early is the
administering of a pretest. After a student’s misconception has been identified, and as
students work in small groups, I will target those students and attempt to guide them to a
more complete understanding. The final assessment will show what students were
successful in incorporating the new knowledge and amending their previous framework
to get to a more complete understanding of the concept.
Backwards Design Stage one: Identifying desired results
This unit is part of the ninth grade curriculum at Pennfield Middle School. The learning
objectives have been shaped through the Pennsylvania. state standards, the North Penn
School District’s ninth grade science curriculum, the lesson’s enduring understandings,
and the lesson’s essential questions. The unit is comprised of approximately fifteen class
periods lasting 40 minutes each. The assessments are largely a presentation of students’
analysis of information, making a decision based on that analysis, and defending their
analysis through their mastery of the concepts of energy conservation, energy
transformation, the influence of non-conservative forces, and the ability to quantify their
33
argument through mathematics. In order to begin this unit, students must possess
previous knowledge in these areas:
Define and calculate speed and velocity
Define and calculate acceleration
Newton’s Laws of Motion
Define and calculate force
Define and calculate momentum
Define work and solve problems using work
Define and solve problems using mechanical advantage
Define Energy
Calculate kinetic and potential energy problems
Define and describe the principle of the conservation of energy
Enduring understandings, Essential questions, Learning outcomes
EU #1: Scientific knowledge is continually, although not steadily increasing and
changing through the results of experiments and the bridges built between experimental
observations and underlying concepts and theories.
Q #1: Is nuclear energy a viable energy option?
LO #
1) Students will describe nuclear fusion and nuclear fission
2) Students will compare and contrast nuclear fission and fusion
3) Students will discuss the pros and cons of nuclear fission power generation
4) Students will discuss the problems with designing nuclear fusion reactors
EU #2: Examples of all levels and areas of science are found in daily life and in modern
human development.
Q #2: In what ways will alternative energy generation impact the planet?
34
LO #
5) Students will discuss the importance of alternative fuel sources
6) Students will describe the benefits and disadvantages of solar, wind, tidal, and
geothermal energy
EU #3: There are core concepts and processes in science that transcend the arbitrary
boundaries between traditional disciplines.
Q #3: How is energy described in physics, chemistry, & biology, and how are they
related?
LO #
7) Students will describe how energy is transformed from one form to another within
and without systems
8) Students will describe how energy leaves a system during an energy
transformation through non-conservative forces (friction, heat)
9) Students will explain the implausibility of a perpetual motion machine through
the Law of Conservation of Energy
Standards
3.1.
Unifying Themes
3.1.10. GRADE 10
A.
Describe concepts of models as a way to predict and understand science and
technology.
• Apply mathematical models to science and technology. (EU #3, Q #3, LO 7, 8, 9)
B.
Describe patterns of change in nature, physical and man made systems.
• Describe how fundamental science and technology concepts are used to solve
practical problems
(EU #2, Q #2, LO 5 & 6)
• Recognize that stable systems often involve underlying dynamic changes
35
(EU #3, Q #3, LO 7, 8)
3.2.
Inquiry and Design
3.2.10. GRADE 10
A.
Apply knowledge and understanding about the nature of scientific and technological
knowledge.
• Integrate new information into existing theories and explain implied results.
(EU #1, Q #1, LO 1, 2, 3, 4)
B.
Apply process knowledge and organize scientific and technological phenomena in
varied ways.
• Develop appropriate scientific experiments: raising questions, formulating
hypotheses, testing, controlled experiments, recognizing variables, manipulating
variables, interpreting data, and producing solutions.
(EU #1, Q #1, LO 1, 2, 3, 4)
• Use process skills to make inferences and predictions using collected information
and to communicate, using space / time relationships, defining operationally.
(EU #2, Q #2, LO 5 & 6)
C.
Apply the elements of scientific inquiry to solve problems.
• Generate questions about objects, organisms and/or events that can be answered
through scientific investigations.
• Evaluate the appropriateness of questions.
• Conduct a multiple step experiment.
(EU #1, Q #1, LO 1, 2, 3, 4)
(EU #1, Q #1, LO 1, 2, 3, 4)
(EU #2, Q #2, LO 5 & 6)
• Suggest additional steps that might be done experimentally.
(EU #1, Q #1, LO 1, 2, 3, 4)
D.
Identify and apply the technological design process to solve problems.
• Examine the problem, rank all necessary information and all questions that must be
answered.
(EU #1, Q #1, LO 1, 2, 3, 4)
• Propose and analyze a solution.
(EU #1, Q #1, LO 1, 2, 3, 4) (EU #2, Q #2, LO 5 & 6)
• Communicate the process and evaluate and present the impacts of the solution.
(EU #2, Q #2, LO 5 & 6)
3.4 Physical Science, Chemistry and Physics
36
3.4.10. GRADE 10
B. Analyze energy sources and transfers of heat.
• Use knowledge of conservation of energy and momentum to explain common
phenomena (e.g., refrigeration system, rocket propulsion).
(EU #2, Q #2, LO 5 & 6)
Unit Objectives
• Students will discuss the importance of alternative fuel sources
•
Students will describe the benefits and disadvantages of solar, wind, tidal, and
geothermal energy
•
Students will describe how energy is transformed from one form to another within
systems
•
Students will describe how energy leaves a system during an energy
transformation through non-conservative forces (friction, heat)
•
Students will describe nuclear fusion and nuclear fission
•
Students will compare and contrast nuclear fission and fusion
•
Students will discuss the pros and cons of nuclear fission power generation
•
Students will discuss the problems with designing nuclear fusion reactors
Backwards design stage two: Assessment evidence
Assessment activity 3:
1) Goal: Students to examine how wind power generation works, and to ascertain its
feasibility in their area.
2) Role: The students act as an engineer designing and testing different materials and
shapes in order to build the most efficient and durable wind generator.
3) Audience: Teacher and peers
4) Situation: Students are given basic plans for a wind generator. The generator and
base is the same for all engineering groups. The students are to draw on previously
learned material to plan their design. The students must test the types of materials,
37
and how to shape those materials to make the best generator. Students then write a
critical analysis of their design and offer ways to improve their design. The
group’s generator that delivers the most current over 3 minutes gets a 5 point bonus
on the assessment 7.
5) Product: A working wind generator, and critical analysis. Worth 8% of the grade
for the unit.
6) Standards:
a) Wind generator graded on output efficiency. 75% to 100% is 20 points, 50% to
74% is 15 points, 25% to 49% is 10 points, 1% to 24 % is 5 points, and 0% is 0
points.
b) Critical analysis needs to explain sources of error, and ways to improve
performance.
Assessment activity 4:
1) Goal: For students to get an appreciation for the amount of energy found in the
tides. For students to examine what types of energy production are feasible in their
local area.
2) Role: Student as a concerned citizen
3) Audience: Teacher and peers
4) Situation: Teacher short lecture on tidal generation. Teacher guided discussion of
tidal generation. Students write individual opinions on the effects of tidal power in
PA, and write a convincing letter to environmental groups in New Jersey to get
them to pressure the New Jersey State government for the implementation of tidal
power plants.
5) Product: The opinion piece on tidal power in PA (Delaware bay, and Lake Erie are
only 2 possible places), and the letter to the environmental groups in New Jersey.
Worth 8% of the grade for the unit.
6) Standards:
a) Opinion piece should detail areas that tidal power in PA is viable, possible
ways it could be implemented, and why it should or should not be
implemented.
38
b) Letter needs to list advantages of tidal power in a coherent way to convince the
environmental groups to support tidal generation in New Jersey. (Letter should
detail benefits to environment and how negative effects could be mitigated.
Backwards Design stage Three: The Learning Plan
Where: At the beginning of each lesson students are given a list of topics that are covered
in the unit. At the beginning of every class the class objectives with learning outcomes are
posted on the board, and gone over.
Unit Pacing
Lessons 1 through 4 address Eu # 2, EQ #2 and LO # 10 & 11
EU #2: Examples of all levels and areas of science are found in daily life and in modern
human developments
Q #2: In what ways will alternative energy generation impact life at the local through
global level?
LO #
10) Students will discuss the importance of alternative fuel sources
11) Students will describe the benefits and disadvantages of solar, wind, and tidal
Pre-test: Administered before the lessons in order to ascertain misconceptions and
weaknesses. Weaknesses are evaluated and addressed during the lessons
Lesson 1
Do we need alternative fuel sources?
Hook: Students brainstorm in small groups reasons that we need fuel sources other than
fossil fuels.
39
Experience: Develop a class list of the reasons for alternative fuel sources. Students
read the E-zine article on why alternative fuels are needed. Students then compare their
list to the article, and decide to add or delete to the master list. Students then make
proposals for the county government to implement energy policy. Students must give
logical reasoning for the policies.
Resource: E-zine article: http://ezinearticles.com/?Alternative-Energy---Why-do-weNeed-it?&id=801280
Reflection: Students are asked to reflect on alternative energies and discuss their ideas
and feelings on them in a large group discussion at the end of class.
Lesson 2
Solar Power
Hook: Today we are going to cook something in a pizza box using the sun as our energy
source.
Experience: Students perform a solar cooking lab. Students construct their group’s solar
oven in the first class period. The following class period students cook a muffin or
something they bring from home based upon teacher’s approval. During cooking
students read about solar energy and answer question about them.
Resources: Pizza box solar oven instruction:
http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/other/solar.html
Solar energy information and quiz adapted from:
http://www.darvill.clara.net/altenerg/solar.htm
Reflection: Students are asked to describe the experience and relate it to their own lives.
Lesson 3
40
Wind Power
Hook: Who can build the best wind generator? Each lab group is a design team. The
team that designs the best wind generator gets a 5 point bonus added to the final
assessment.
Experience: Lab groups are given kits to build their own wind generator. The students
will then decide on what materials and shape to make the wind turbine. If students use
light weak materials, it will spin faster and be more efficient, but it will be less
dependable and prone to breaking. If students use the heavy most durable parts, it will
have poor efficiency, but better dependability. Students then write a critical analysis of
their design and offer ways to improve their design.
Resources: Instructions for building the turbine http://www.re-energy.ca/pdf/windturbine.pdf
Reflection: Students are asked why wind power is not used more if it is easy enough for a
kid to do it.
Lesson 4
Tidal Power
Hook: How many gallons of water can you lift? How much energy does it take to move
an ocean? What if we used that energy to generate electricity?
Experience: Students discuss the advantages and disadvantages of generating tidal
power. Students also discuss the possible environmental effects of Tidal energy.
Students assess if tidal energy would have an impact on electricity generated in PA and
develop a proposal to build a tidal power station in New Jersey.
Resources: Tidal generation information: http://www.darvill.clara.net/altenerg/tidal.htm
41
Reflection: Students are asked to reflect on could all the Earth’s energy needs be met if
all of the power held in the tides is converted into usable energy.
Lesson 5 (Fully developed lesson)
Nuclear Power
Nuclear fission
When a neutron is fired at a uranium-235 nucleus, the nucleus captures the neutron. It
then splits into two lighter elements and throws off two or three new neutrons (the
number of ejected neutrons depends on how the U-235 atom happens to split). The two
new atoms then emit gamma radiation as they settle into their new states. (John R.
Huizenga, "Nuclear
fission", in
AccessScience@McGraw-Hill,
http://proxy.library.upenn.edu:3725) There are three things about this induced fission
process that make it especially interesting:
4)
The probability of a U-235 atom capturing a neutron as it passes by is fairly
high. In a reactor working properly (known as the critical state), one neutron
ejected from each fission causes another fission to occur. (Huizenga)
5)
The process of capturing the neutron and splitting happens very quickly, on the
order of picoseconds (1x10-12 seconds). (Huizenga)
6)
An incredible amount of energy is released, in the form of heat and gamma
radiation, when a single atom splits. The two atoms that result from the fission
later release beta radiation and gamma radiation of their own as well. The
energy released by a single fission comes from the fact that the fission
products and the neutrons, together, weigh less than the original U-235 atom.
The difference in weight is converted directly to energy at a rate governed by
the equation E = mc2. Something on the order of 200 MeV (million electron
volts) is released by the decay of one U-235 atom.4That may not seem like
much, but there are a lot of uranium atoms in a pound of uranium. A pound of
4
1 eV is equal to 1.602 x 10-12 ergs, 1 x 107 ergs is equal to 1 joule, 1 joule equals 1 watt-second, and 1
BTU equals 1,055 joules).
42
highly enriched uranium used to power a nuclear submarine is on the order of
a million gallons of gasoline. (Huizenga)
There are some drawbacks of nuclear fission reactors, namely:
5) Mining and purifying uranium has, historically, been a process that leaves very
toxic byproducts.
6) Improperly functioning nuclear power plants can create big problems. The
Chernobyl disaster is a good recent example that dramatically shows the worstcase scenario.
Chernobyl scattered tons of radioactive dust into the
atmosphere.
7) Spent fuel from nuclear power plants is toxic for centuries, and, as yet, there is
no safe, permanent storage facility for it. Yucca mountain in Nevada is the
future permenant depository when it becomes operational.
8) Transporting nuclear fuel to and from nuclear plants poses some risk, although
to date, the safety record in the United States has been good.
Nuclear Fusion
The sun releases energy through nuclear fusion reactions. The immense temperature and
pressure in the Sun forces hydrogen atoms fuse into deuterium, then the deuterium atom
fuses together with another hydrogen atom to form a tritium atom, and then the tritium
atom fuses with another hydrogen atom to from a helium atom. The resulting helium
atom’s mass is less than four hydrogen atoms. The missing mass is transformed into
energy by Einstein’s E=mc2 equation (Figures 1 and 2). The reaction between the nuclei
of the two heavy forms (isotopes) of hydrogen - deuterium (D) and tritium releases 17.6
MeV (2.8 x 1012 joule).
There are two methods of achieving nuclear fusion in a reactor.
They are Inertial
Electrostatic Confinement (IEC) and toroidal magnetic field for confining a plasma
(Tokamak) Using these two methods different fuels can be used (Hydrogen, deuterium,
tritium, and helium-3) all with positive and negative attributes. In general most of the
positive attributes have to do with non-radioactive waste, and no danger of a meltdown.
43
The negative attributes with the hydrogen based fuels are abundant neutron production
which degrades the containment walls of reactors. The negative attributes of the helium3 based fuel is the limited availability of helium-3 on Earth, and high starting temperature
for the fusion of helium-3.
EU #1: Scientific knowledge is continually, although not steadily increasing and
changing through the results of experiments and the bridges built between experimental
observations and underlying concepts and theories
Q #1: Is nuclear energy a viable energy option?
LO #
12) Students will describe nuclear fusion and nuclear fission
13) Students will compare and contrast nuclear fission and fusion
14) Students will discuss the pros and cons of nuclear fission power generation
15) Students will discuss the problems with designing nuclear fusion reactors
Hook: We all know what nuclear bombs can do. Their destructive power is enormous.
Nuclear power has become one of the most feared power sources on the planet. Is this
fear justified? What are the real dangers and benefits behind nuclear Power?
Experience: Students will research nuclear power in small groups and design a
PowerPoint presentation that outlines the pros and cons of nuclear power generation, and
advocates a position of the building of nuclear power plants or a ban on the building of
nuclear power plants, and each will individually write a persuasive essay stating why
nuclear reactors should be pursued or banned.
44
Step one: Research nuclear processes
Students research the process of nuclear fission and nuclear fusion. Students need to
explain the process and energy released by both types on nuclear power
Step two: Students research the basic method by which nuclear fission plants operate.
Students research the parts of a reactor, the method of fission in the reactor, the cooling
of the reactor, and the waste generated by the reactor.
Step three: Pros and cons of nuclear fission
Students research the benefits and drawbacks of nuclear fission plants. Students need to
take into account economic costs and benefits, environmental costs and benefits, security
or safety costs and benefits, impact of added electrical generation to the public.
Step four: Nuclear fusion
Students research methods that nuclear fusion reactors operate. Students give
descriptions of reactors, the energy produced, and the waste generated by the reactor.
Step five: Pros and cons of nuclear fusion
Students research the benefits and drawbacks of nuclear fusion. Students need to take
into account whether it is worth it to continue research into fusion energy, the current
problems with fusion reactors, the benefits and drawbacks of helium 3 reactors and the
availability of helium 3 fuel.
45
Step six: Students write a persuasive essay stating why nuclear reactors should be
pursued or banned.
Resources: Nuclear Power project packet, computer with internet access, PowerPoint
Assessment: Project rubric for PowerPoint, student essay
Reflection: The student essay is the reflection for this activity.
Lesson 6
Energy flow through and between systems
EU #3: There are core concepts and processes in science that transcend the arbitrary
boundaries between traditional disciplines.
Q #3: How is energy described in physics, chemistry, & biology, and how are they
related?
LO #
16) Students will describe how energy is transformed from one form to another within
and without systems
17) Students will describe how energy leaves a system during an energy
transformation through non-conservative forces (friction, heat)
Hook: There is energy all around us. We are going to be detectives and determine the
possible paths different forms of energy take to become electricity in your home.
Experience: Energy flow using inspiration. Students use inspiration to follow the flow
of energy within and without different systems. Students are given a source of energy
and must describe the different transformations it goes through to generate electricity.
46
Example: Energy from the sun is used by plants to generate heat and to activate a
chemical reaction to form a carbohydrate and oxygen, that carbohydrate is compressed
over time and becomes coal, the coal is burned releasing the energy from the sun. The
activity shows students that the total amount of energy in the universe will always stay
constant.
Assessment: Inspiration energy flow sheets.
Reflection: Students are asked to reflect on why energy is so misunderstood in the world,
and what do they feel they do not understand about energy.
Resources:
1) Pizza box solar oven instruction:
http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/other/solar.html
2) Solar energy information and quiz adapted from:
http://www.darvill.clara.net/altenerg/solar.htm
3) Instructions for building the turbine http://www.re-energy.ca/pdf/wind-turbine.pdf
4) Tidal generation information: http://www.darvill.clara.net/altenerg/tidal.htm
5) The International Atomic Energy Agency (IAEA) Gives great information on nuclear
rules and regulations around the world as well as explanations of fusion and fission
nuclear processes: http://www.iop.org/EJ/journal/NuclFus
6) Great site for nuclear power generation lessons and explanations (Nuclear Regulatory
Commission) : http://www.nrc.gov/reading-rm/basic-ref/teachers/unit3.html
7) Teacher’s domain on wind power and wind power resources:
http://www.teachersdomain.org/resources/psu06/energy21/sci/rotor/index.html
8) Great site for energy transformations specializing on alternative energy:
http://www.nvsd44.bc.ca/sites/ReportsViewOnePopM.asp?RID=3811
47
Appendix:
1) Pretest
2) E-zine article: http://ezinearticles.com/?Alternative-Energy---Why-do-we-Needit?&id=801280
3) Nuclear power project packet
48
Appendix 1
Pre-test
Name ___________________________
1) Are coal, oil, and natural gas considered an alternative fuel? (Explain why or why
not)
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
2) What is the difference between nuclear fission and nuclear fusion?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
3) Explain how wind power works.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
4) Can energy be generated from the tides? If so, how?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
5) What are the disadvantages to solar power?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
49
6) Are alternative fuel sources needed? (Explain why or why not)
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
7) After energy is used, what happens to it?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
8) Name an example when energy is generated without moving something.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
9) Is there any difference between energy, power, and force. If so, explain them.
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
10) Is energy recycled? If so, how?
____________________________________________________________________
____________________________________________________________________
____________________________________________________________________
50
Appendix 2
http://ezinearticles.com/?Alternative-Energy---Why-do-we-Need-it?&id=801280
Why Do We Need Alternatives?
To answer that question, we need to start by discussing fossil fuels-what they are,
where they come from, how they are used and the advantages and disadvantages of
each. Within this context, the pressing need for alternatives becomes quite clear.
What are fossil fuels?
Most fossil fuels are formed from the remains of long-dead creatures and plants.
Buried over the course of hundreds of millions of years, these carbon-based deposits
have been converted by heat and pressure over time into such combustible
substances as crude oil, coal, natural gas, oil shales and tar sands. A smaller portion
of fossil fuels is the handful of other naturally occurring substances that contain
carbon but do not come from organic sources.
To make more fossil fuels would require both the creation of new topsoil filled with
hydrocarbons, and time-lots of time. Given estimates of current fossil fuel reserves
worldwide, it's not possible we can wait out the problem, and continue our
dependence on fossil fuels until new reserves are built. At current consumption rates,
the reserves of oil and coal and other fossil fuels won't last hundreds of years, let
alone hundreds of millions of years.
As for creating more, experts have pointed out that it can take close to five centuries
to replace a single inch of topsoil as plants decay and rocks weather. Yet in the
United States, at least, much of the topsoil has been disturbed by farming, leading
still more experts to the disturbing conclusion that in areas once covered by prairie,
the past hundred years of agriculture have caused America's "bread basket' to lose
half of its topsoil as it erodes thirty times faster than it can form.
The Advantages of Fossil Fuels in Energy Production
There are many reasons why the world became dependent on fossil fuels, and
continues to rely on them. For example, it has so far been relatively cost-effective in
the short run to burn fossil fuels to generate electricity at strategic centralized parts
of the grid and to deliver the electricity in bulk to nearby substations; these in turn
deliver electricity directly to consumers. These big power plants burn gas or, less
efficiently, coal. Since so much electricity can be lost over long-distance
transmission, when power needs to be concentrated more in one region than
another, the fuels are generally transported instead to distant power plants and
burned there. Liquid fuels are particularly easy to transport.
Thus far, fossil fuels have been abundant and easily procured. Petroleum reserves
worldwide are estimated at somewhere between 1 and 3.5 trillion barrels. Proven
coal reserves at the end of 2005, as estimated by British, were 909,064 million tons
worldwide. Coal, furthermore, is relatively cheap.
51
Perhaps the simplest reason why the world continues to depend on fossil fuels is that
to do anything else requires change: physical, economical, and-perhaps the most
difficult-psychological. The basic technology for extracting and burning fossil fuels is
already in place, not only in the large power plants but at the consumer level, too.
Retrofitting factories would be cost-prohibitive, but perhaps even more daunting
would be replacing heating systems in every home, factory and building. Ultimately,
however, the true resistance may be our nature. We humans tend to resist change in
general, and in particular those changes that require us to give up longstanding
traditions, alter our ways of thinking and living, and learn new information and
practices after generations of being assured that everything was "fine" with the old
ways.
Why Do We Need Alternatives?
If there are so many reasons to use fossil fuels, why even consider alternatives?
Anyone who has paid the least bit of attention to the issue over the past few decades
could probably answer that question. If nothing else, most people could come up
with the first and most obvious reason: fossil fuels are not, for all practical purposes,
renewable. At current rates, the world uses fossil fuels 100,000 times faster than
they can form. The demand for them will far outstrip their availability in a matter of
centuries-or less.
And although technology has made extracting fossil fuels easier and more cost
effective in some cases than ever before, such is not always the case. As we deplete
the more easily accessible oil reserves, new ones must be found and tapped into.
This means locating oil rigs much farther offshore or in less accessible regions;
burrowing deeper and deeper into the earth to reach coal seams or scraping off ever
more layers of precious topsoil; and entering into uncertain agreements with
countries and cartels with whom it may not be in our best political interests to forge
such commitments.
Finally, there are human and environmental costs involved in the reliance on fossil
fuels. Drilling for oil, tunneling into coalmines, transporting volatile liquids and
explosive gases-all these can and have led to tragic accidents resulting in the
destruction of acres of ocean, shoreline and land, killing humans as well as wildlife
and plant life. Even when properly extracted and handled, fossil fuels take a toll on
the atmosphere, as the combustion processes release many pollutants, including
sulfur dioxide-a major component in acid rain. When another common emission,
carbon dioxide, is released into the atmosphere, it contributes to the "greenhouse
effect," in which the atmosphere captures and reflects back the energy radiating
from the earth's surface rather than allowing it to escape back into space. Scientists
agree that this has led to global warming, an incremental rise in average
temperatures beyond those that could be predicted from patterns of the past. This
affects everything from weather patterns to the stability of the polar ice caps.
Conclusion
Clearly, something must change. As with many complex problems, however, the
solution to supplying the world's ever-growing hunger for more energy will not be as
simple as abandoning all the old methods and beliefs and adopting new ones
overnight. Partly this is a matter of practicality-the weaning process would take
considerable investments of money, education and, most of all, time. The main
52
reason, however, is that there is no one perfect alternative energy source.
Alternative will not mean substitute.
What needs to change?
It seems simplistic to say that what really needs to change is our attitude, but in fact
the basis of a sound energy plan does come down to the inescapable fact that we
must change our way of thinking about the issue. In the old paradigm, we sought
ways to provide massive amounts of power and distribute it to the end users,
knowing that while much would be lost in the transmission, the advantages would be
great as well: power plants could be located away from residential areas, fuels could
be delivered to central locations, and for consumers, the obvious bonus was
convenience. For the most part our only personal connection with the process would
be calling the providers of heating fuel and electricity, and pulling up to the pumps at
the gas station. And the only time we would think about the problem would be when
prices rose noticeably, or the power went out.
There are people who have tried to convince us that there is no problem, and that
those tree-hugging Chicken Littles who talk about renewable and alternative energy
want us all to go back to nature. More often than not these skeptics' motivations for
perpetuating this myth falls into one of two categories: one, they fear what they
don't understand and are resistant to being told what to do, or two, they have some
political or financial stake in enabling our fossil-fuel addiction. (And sometimes both.)
The reality is that except for altering our ways of thinking, there will not be one
major change but a great many smaller ones. A comprehensive and successful
energy plan will necessarily include these things:
• Supplementing the energy produced at existing power plants with alternative
energy means, and converting some of those plants to operate on different
"feedstock" (fuels)
• Shifting away from complete reliance on a few concentrated energy
production facilities to adding many new and alternative sources, some
feeding into the existing "grid" and some of supplying local or even
individual needs
• Providing practical, economical and convenient ways for consumersresidences, commercial users, everyone-to adapt and adopt new
technologies to provide for some or all of their own energy needs
• Learning ways in which we can use less energy now ("reduce, reuse,
recycle"), using advances in technology as well as simple changes in
human behavior to reduce consumption without requiring people to make
major compromises or sacrifices
Alternative Energy is a crucial link in our energy future if we are to cut the oil cord.
We present thoughts, ideas, info and news about alternative energy at Alternative
Energy HQ. Get a free copy of our book "Cutting the Oil Cord - Using Alternative
Energy in Your Life" at - http://alternativeenergyhq.com
Article Source: http://EzineArticles.com/?expert=Kevin_Rockwell
53
Appendix 3
Nuclear Power Project
Introduction
We all know what nuclear bombs can do. Their destructive power is enormous. Nuclear
power has become one of the most feared power sources on the planet. In this project we
will decide if nuclear power should be feared and what is being done to make it safer.
Basic task
Students will research nuclear power in groups of four, design a PowerPoint presentation
that outlines the pros and cons of nuclear power generation, and advocates a position of
the building of nuclear power plants or a ban on the building of nuclear power plants, and
each will individually write a persuasive essay stating why nuclear power should be
pursued or banned.
Process
Step one: Research nuclear processes
Students research the process of nuclear fission and nuclear fusion. Students need to
explain the process and energy released by both types on nuclear power
Step two: Students research the basic method by which nuclear fission plants operate.
Students research the parts of a reactor, the method of fission in the reactor, the cooling
of the reactor, and the waste generated by the reactor.
Step three: Pros and cons of nuclear fission
Students research the benefits and drawbacks of nuclear fission plants. Students need to
take into account economic costs and benefits, environmental costs and benefits, security
or safety costs and benefits, impact of added electrical generation to the public.
Step four: Nuclear fusion
54
Students research methods that nuclear fusion reactors operate. Students give
descriptions of reactors, the energy produced, and the waste generated by the reactor.
Step five: Pros and cons of nuclear fusion
Students research the benefits and drawbacks of nuclear fusion. Students need to take
into account whether it is worth it to continue research into fusion energy, the current
problems with fusion reactors, the benefits and drawbacks of helium 3 reactors and the
availability of helium 3 fuel.
Step six: Students write a persuasive essay stating why nuclear reactors should be
pursued or banned. Essay needs to have a clear pro/con nuclear power argument. You
may be for one method of nuclear power and against the other. Every point made in the
essay should be backed by facts presented in the PowerPoint or referenced at the end of
the essay. The essay should be at least 200 words and no more than 800 words.
Assessment:
Nuclear Power Rubric
Process
Safety
Wastes
Cost/Benefit
Essay
References
Fission
Fusion
Fission
Fusion
Fission
Fusion
Fission
Fusion
Nuclear
Energy
Sources of
information
Not Present
0
0
0
0
0
0
0
0
0
0
Poor
5
5
4
4
4
4
5
5
7
Proficient
11
11
8
8
8
8
11
11
14
Excellent
15
15
10
10
10
10
15
15
20
3
6
10
Total Score ____________
55
(Total score/130) x 100% = ____________
Process: Not present scores reflect no explanation of the process of nuclear reactions,
Poor scores reflect little more than the mention of nuclear reactions with very little
coherent detail on the process, Proficient scores reflect a coherent organized description
of nuclear reactions and why/how they result in the release of energy, Excellent scores
reflect an understanding of why/how fusion and fission only work for particular elements.
Safety: Not present scores reflect no mention of the safety issues for each kind of nuclear
power, Poor scores reflect on incomplete development of topic where possible hazards
and past failures are not covered effectively, Proficient scores reflect through listing and
explanation of safety issues facing nuclear power, Excellent scores reflect a through
listing and explanation of safety issues facing nuclear power, and ways the industry is
trying to mitigate dangers.
Wastes: Not present scores reflect little to no mention of nuclear wastes, Poor scores
reflect types of waste with no description of how they are processed, Proficient scores
reflect the types of waste generated and how they are processed and stored, Excellent
scores reflect the types of waste generated and how they are processed and stored, and
detail methods for handling wastes in the future.
Cost/Benefit: Not present scores reflect no attention to the cost/benefit breakdown of
nuclear power, Poor scores reflect little thought or research into nuclear power,
Proficient scores reflect a logical breakdown of the benefits and drawbacks (economic,
environmental)to nuclear power, Excellent scores reflect a logical breakdown of the
benefits and drawbacks (economic, environmental)to nuclear power, and include a
reasoned approach to whether either form of nuclear power should be utilized to meet the
energy needs now and in the future.
Essay: This is the individual section of the essay. This is where you show your
understanding of nuclear power and is independent of group work. Not present scores
reflect not submitting an essay, Poor scores reflect little coherent knowledge of nuclear
processes and the debate on the future of nuclear energy, Proficient scores reflect
coherent knowledge of nuclear processes and the debate on the future of nuclear energy,
Excellent scores reflect clear understanding of nuclear processes and a command of the
issues facing nuclear power today.
References: Not present reflects no references provided, Poor reflects 1- 3 references
provided, Proficient reflects 4-6 references provided, Excellent reflects more than 6
references in MLA format
56
References
(Pedagogy Section)
Wiggins, g., McTighe, J. (2005) Understanding by design, New York: Prentice Hall
Miriam Reiner, James D. Slotta, Michelene T. H. Chi and Lauren B. Resnick (2000),
Naive Physics Reasoning: A Commitment to Substance-Based Conception, Cognition and
Instruction, Vol. 18, No. 1, pp. 1-34
John P. Smith, III, Andrea A. diSessa and Jeremy Roschelle (1993 – 1994),
Misconceptions Reconceived: A Constructivist Analysis of Knowledge in Transition, The
Journal of the Learning Sciences, Vol. 3, No. 2, pp. 115-163
Jones, B. F., Idol, L., (1990), Dimensions of thinking and cognitive instruction:
Implications for Educational Reform, Lawrence Erlbaum Associates
Clement, J. (1987). Overcoming students' misconceptions in physics: The role of
anchoring intuitions and analogical validity. In J. Novak (Ed.). Proceedings of the second
international seminar misconceptions and educational strategies in science and
mathematics. (Vol. III, pp. 84-96). Ithaca, NY: Cornell University.
Chong, L. (2005), Making sense of learning with schemas. CDTLink Teaching Methods,
Vol 9, No 1
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