Environmental Science Table of Contents

Environmental Science Table of Contents
47
Lab 4
Energy Sources and Alternative Energy
Concepts to Explore
• Energy
• Non-renewable sources
• Passive solar energy

• Active solar energy
• Photovoltaics
• Wind energy
Introduction
Energy is essential for life to exist in any environment. As
humans, we consume huge quantities of energy
every day. This, however, comes with many consequences.
Although energy is abundant everywhere, useful
energy is much more difficult to produce and less efficient for
our daily activities. Over 90% of produced ener-
gy comes from non-renewable resources. These include oil,
natural gas, coal, and uranium. Not only are our
sources of fossil fuels and other nonrenewable energy sources
depleting, but many of these sources produce
toxins that are harmful to our bodies and the environment.
Fossil fuel depletion, deforestation, pollution, and
global warming are just a few negative effects that come from
the combustion of many nonrenewable energy
sources.
Non-renewable Sources
Oil is derived from the remains of plants and animals that lived

in aqueous
environments millions of years ago. Over very long periods of
time, the
heat from the Earth’s core and the pressure from the sand, silt,
and rock
that deposited on top of it turns the remains into crude oil.
Scientists and
engineers explore areas to find rocks that indicate the presence
of oil un-
derneath, and drill through them to tap into the reservoir
holding the yel-
lowish-black substance. After the oil is drilled, it is sent to a
refinery to be
separated into usable petroleum products—most of which are
used to pro-
duce energy. These include: heating oil, jet fuel, heavy fuel oil,
liquefied
petroleum gases, and gasoline.
? Did You Know...
The following products are
made from petroleum?
• Ink
• Deodorant
• Crayons
• Dishwashing liquid
• Eyeglasses
• CDs and DVDs
• Tires
• Ammonia
• Artificial heart valves
Coal is another nonrenewable energy source that is derived from

sedimentary rock comprised mainly of car-
bon and hydrocarbons. It takes millions of years to create and
forms from dead plants that became trapped
under dirt and water. There are four main types of coal:
anthracite, bituminous, subbituminous, and lignite.
Coal is classified into these groups based on the amount of
carbon it contains. When coal is buried less than
200 feet underground, surface mining technologies can be used
to extract it. However, it if is deeper than 200
feet, underground mining is performed to reach and extract the
coal. More than 90% of the coal mined in the
US is used for generating electricity. Even though coal is an
inexpensive fuel source, it is important to re-
49
member that mining alters the topography and also can cause
secondary pollution to waterways and the air.
Similar to oil and coal, natural gas is produced from decaying
plant material and very long periods of time. It
is used in industrial and residential arenas for heating and
electricity. Although natural gas is a relatively
clean-burning fossil fuel, it is not without harmful
environmental impacts.
While products from oil, coal, and natural gas help to do many
things, finding, moving, and using them can

harm the environment through air, water, and other secondary
pollution. There are many ways that we can
reduce the amount of energy consumed in our daily lives.
Proper use of insulation, using energy efficient light
bulbs, use of programmable thermostats, carpooling, and even
driving the speed limit can all help conserve
energy, the environment, and even money! Two major forms of
renewable energy are also being utilized -
solar and wind energy.
Earth receives most of the sun’s energy through forms of light
to minimize the dependence on nonrenewable
sources. This solar energy can be converted into heat and other
forms of energy such as electricity. The
sun’s light is Earth’s most abundant source of energy and is also
free of cost. For these reasons, scientists
have studied ways to convert and harness the energy of the sun
for centuries. There are four major forms of
solar energy: passive, active, photovoltaic, and solar thermal
electric energy. Each form of solar energy has
its unique set of advantages and disadvantages, but used
properly can help in the conservation of energy
and our planet.
Passive Solar Energy
When the sun is the only moving object and source of light
and/or heat in energy transfer the process is
called passive. This means that no electricity is produced and
only the sun is used to transfer energy to an-
other object or group of objects. Passive solar energy is utilized
in many households and buildings. Window
placement, insulation, and ventilation are key components to

properly utilize the sun’s power in order to keep
cool in the summer and warm in the winter. Proper construction
planning is key for these situations.
Active Solar Energy
Active solar energy, also known as active solar heating, is
similar to its passive counterpart in the way that it
captures energy from the sun. However, it goes one step further
and uses a liquid to store and transfer the
energy. Active solar heating systems often use the sun to heat
an enclosed fluid such as water. Once heated
the fluid can be stored for later and used the next time someone
needs to take a hot shower! These systems
often use pumps to move the fluid during the heat transfer
process, and can become much more complicat-
ed. This makes active solar heating less efficient because pumps
require additional power to run.
50
Photovoltaics
When electrical energy is produced directly from the energy of
the sun PV cells, or photovoltaic cells, are
used. These cells are very common and often found on top of
street lights, used in solar powered calculators,

residential homes, and even watches. PV cells consist of tiny
strips of semiconductors, such as silicon, which
are joined together. When the sun strikes these strips the
material becomes excited. If there is enough energy
present, electrons are emitted from the excited atoms. This flow
of electrons produces an electrical current,
which can then be used as energy. Photovoltaics can be very
expensive in large applications, but cost has
continuously fallen as the technology is enhanced.
Figure 1: Several different designs of wind turbines exist, but
the most common looks like an
oscillating fan or wind mill. All of the different styles of
turbines try to maximize the efficiency of
the turbine at different wind speeds.
Focusing solar energy using mirrors can help intensify heat
transfer. This ancient technology has recently
been utilized in large scale projects to produce electrical
energy. In this process reflected sunlight is focused
on pipes of oil, which are then heated. Oil is used because it is
much more conductive than water and can be
heated with greater ease. The heat in the oil is then transferred
to water and creates steam. This steam spins
a turbine to create an electrical current. Converting the sun’s
energy in this manner requires larger areas of
51

land but is very useful. Solar thermal electric energy can even
be used to increase the efficiency of heat
pumps and power plants.
Wind Energy
Solar energy is what drives our planet. Almost every living
organism converts the sun’s rays into a useful form
of energy. At a quick glance there seem to be very few
drawbacks from using solar energy. However there
are some big issues with using solar power for energy. First,
solar energy can only be used in places where
sunlight is abundant and when it is available. Solar energy is
not available at night and it would be pointless
to put PV cells in an area where the sun rarely shines. Clouds
can also create a problem when trying to cap-
ture energy from the sun. If you need power but have no light
you are just out of luck. Second, storing solar
energy is difficult and inefficient. This means that if you do not
need the energy at the time it is converted it
will be wasted. Finally, the equipment involved in many solar
devices is expensive and tough to maintain.
With this being said, advancements are being made every day
and solar energy continues to expand.
Like solar, wind power has many advantages to it. Unlike fossil
fuels, wind power is clean, abundant and free.
Wind is even more abundant than energy from the sun since it
can potentially be harnessed 24 hours out of
the day. Wind energy uses a turbine to convert kinetic energy
from the wind into mechanical energy, which in

turn produces electricity.
Just like solar energy, wind has its disadvantages. The major
disadvantage is that wind is unpredictable. Alt-
hough unreliability can be reduced by choosing proven
locations, no one can precisely predict wind speeds
over large areas of land. This uncertainty requires the use of
backup energy sources and storage devices.
Wind farms are also by nature, very large and expensive. Their
size makes them unappealing near populated
areas, which means that they must be a great distance from the
area they are actually supplying power to.
Large wind farms can also disrupt radio, television, and phone
reception. Although there are problems with
wind energy production, the global power output due to wind
has increased exponentially over the years.
This statistic emphasizes the need for future development in
alternative energy sources in order to maintain
the planet we live on today.
52
Experiment 1: The Effects of Coal Mining
Coal mining, particularly surface mining, leads to large areas of
land being temporarily disturbed. The mine
workings collect and conduct water that is in contact with the
widespread pyrite, a mineral that produces iron

and sulfuric acid when exposed to air and water. In this lab, you
will test the effect of pyrite and coal on fresh
water. Follow the procedure below to complete Experiment 1
on the effects of coal mining.
Materials
(2) 100 mL Beakers
1 tsp. Crushed pyrite
1 tsp. Activated carbon
6 pH test strips
Permanent marker
Measuring spoon
*Water
*You must provide
Procedure
1. Read through the Experiment 1 procedure and then record

your hypothesis on the effects of pyrite and
coal on water acidity on the Week 4 Lab Reporting Form.
2. Label three beakers: Water, Pyrite, and Carbon.
3. Pour 100 mL of water into each beaker.
4. Test and record the initial pH of each beaker and record the
results in Table 1 on the Week 4 Lab Report-
ing Form.
5. Place 1 heaping teaspoon of the crushed pyrite and activated
carbon into their corresponding beakers.
6. Set the beakers in a warm place for 48 hours, then test the pH
of each. Record the results in Table 1 and
answer the Post-Lab Questions on the Week 4 Lab Reporting
Form.
53
Experiment 2: Solar Energy

The sun’s energy is free, plentiful, non-polluting, and can be
converted into electricity with the use of photo-
voltaic cells. Also called a solar cell, these panels capture
sunlight and emit a current that can be used to
power many things, including the small motor attached to the
solar panel in your kit. However, many people
argue that this source of energy is unreliable due to varying
weather conditions. In this experiment, you test
the effectiveness of solar energy under direct sunlight and
compare it to solar energy subjected to a number
of independent variables. Follow the procedure below to
complete Experiment 2 on solar energy
Materials
Solar cell, motor, and rotating disk
Permanent marker
Red, green, blue and yellow filters (cellophane)
Aluminum foil
Protractor
*Incandescent light source (fluorescent and halo-
gen light sources are not suitable for this experi-
ment)

*You must provide
Procedure
1. Read through the Experiment 2 procedure and then record
your hypotheses on the effectiveness of solar
energy under direct sunlight and when exposed to other
variables on the Week 4 Lab Reporting Form.
2. Record the weather of the day in the bottom of Table 2 on the
Week 4 Lab Reporting Form.
3. Draw a dot on the disk using the permanent marker, near the
outer circumference of the circle. This will
help you to visualize the rotation of the motor once it starts
spinning.
Note: The faster the disc spins, the more energy the solar panel
is producing.
4. Test your solar motor by holding it close to an incandescent
light source, and record the wattage in Table
2. Observe the efficiency (the speed of the rotating disc) of the
solar cell as you vary the distance be-

tween the motor and the light source by moving the motor
closer and farther from the bulb You may need
to give the wheel a tiny nudge to get it started. For all
observations in this experiment, you do not need to
calculate the exact rotation speed but may use observational
values such as very slow, slow, medium,
fast, very fast.
Note: Incandescent light sources refer to light bulbs which
encase a filament wire. They are typically
shaped like an upside-down pear and screw into table lamps. Do
not use a fluorescent or halogen
light source.
5. Take the motor outside and face the solar panel directly at the
sun (even when overcast the sun is still
54
Weather and Climate Change
present). Observe the efficiency of the solar cell as you hold it
in direct sunlight. Record your observations
in Table 2 on the Week 4 Lab Reporting Form.

6. Face the solar panel exactly 45 degrees away from the sun,
using the protractor to measure the angle
from the sun. Observe the efficiency of the solar cell when it is
struck by sunlight at this angle. Record
your observations in Table 2 on the Week 4 Lab Reporting
Form.
7. Use the aluminum foil to create a reflector that reflects
sunlight onto the solar panel. This should not cover
the panel, but enhance the amount of sunlight that hits the panel
surface. Observe the efficiency of the
solar panel with the reflector and record your observations in
Table 2 on the Week 4 Lab Reporting Form.
8. Use the black construction paper to shade 25%, 50% and 75%
of the solar panel. Observe the efficiency
of the solar panel under each condition and record your
observations in Table 2 on the Week 4 Lab Re-
porting Form.
9. Fold a piece of the red cellophane over two times so that you
have a piece of cellophane that is four-
layers thick (it should be one quarter of the original size).

10. Hold the red cellophane over the exposed portion of the
solar panel, and observe the efficiency of the so-
lar panel. Repeat this process with the yellow, green, and blue
cellophane. Observe the efficiency of the
solar panel when each color filter is used to cover the solar
panel. Record your observations in Table 2
and answer the post lab questions on the Week 4 Lab Reporting
Form.
Figure 2: Each cellophane sheet should be folded into quarters
to create the desired rotational effect.
55
Weather and Climate Change
Appendix
Good Lab Techniques
56
Good Lab Techniques

Good Laboratory Techniques
Science labs, whether at universities or in your home, are places
of adventure and discovery. One of the first
things scientists learn is how exciting experiments can be.
However, they must also realize science can be
dangerous without some instruction on good laboratory
practices.
• Read the protocol thoroughly before starting any new
experiment.
You should be familiar with the action required every step of
the
way.
• Keep all work spaces free from clutter and dirty dishes.
• Read the labels on all chemicals, and note the chemical safety
rating
on each container. Read all Material Safety Data Sheets
(provided
on www.eScienceLabs.com).
• Thoroughly rinse lab ware (test tubes, beakers, etc.) between
experi-
ments. To do so, wash with a soap and hot water solution using
a
bottle brush to scrub. Rinse completely at least four times. Let

air
dry
• Use a new pipet for each chemical dispensed.
• Wipe up any chemical spills immediately. Check MSDSs for
special
handling instructions (provided on www.eScienceLabs.com).
• Use test tube caps or stoppers to cover test tubes when shaking
or
mixing – not your finger!
A B C
Figure 1: A underpad will
prevent any spilled liquids
from contaminating the sur-
face you work on.
Figure 2: Special measuring tools in make experimentation
easier and more accu- rate in
the lab. A shows a beaker, B graduated cylinders, and C test
tubes in a test tube rack.
67

Good Lab Techniques
• When preparing a solution, refer to a protocol for any specific
instructions on preparation. Weigh out the desired amount of
chemicals, and transfer to a beaker or graduated cylinder.
Add LESS than the required amount of water. Swirl or stir to
dissolve the chemical (you can also pour the solution back
and forth between two test tubes), and once dissolved, trans-
fer to a graduated cylinder and add the required amount of
liquid to achieve the final volume.
• A molar solution is one in which one liter (1L) of solution
con-
tains the number of grams equal to its molecular weight.
For example:
1M = 110 g CaCl x 110 g CaCl/mol CaCl
(The formula weight of CaCl is 110 g/mol)
Figure 3: Disposable pipettes aid in ac-
curate measuring of small volumes of
liquids. It is important to use a new pi-
pette for each chemical to avoid con-
tamination.

• A percent solution can be prepared by percentage of weight of
chemical to 100ml of solvent (w/v) , or
volume of chemical in 100ml of solvent (v/v).
For example:
20 g NaCl + 80 mL H2O = 20% w/v NaCl solution
• Concentrated solutions, such as 10X, or ten times the normal
strength, are diluted such that the final
concentration of the solution is 1X.
For example:
To make a 100 mL solution of 1X TBE from a 10X solution:
10 mL 10X TBE + 90 mL water = 100ml 1X TBE
• Always read the MSDS before disposing of a chemical to
insure it does not require extra measures.
(provided on www.eScienceLabs.com)
• Avoid prolonged exposure of chemicals to direct sunlight and
extreme temperatures. Immediately se-
cure the lid of a chemical after use.
• Prepare a dilution using the following equation:

c1v1 = c2v2
Where c1 is the concentration of the original solution, v1 is the
volume of the original solution, and
c2 and v2 are the corresponding concentration and volume of
the final solution. Since you know c1,
68
Good Lab Techniques
c2, and v2, you solve for v1 to figure out how much of the
original solution is needed to make a cer-
tain volume of a diluted concentration.
• If you are ever required to smell a chemical, always waft a gas
toward you, as shown in the figure
below.. This means to wave your hand over the chemical
towards you. Never directly smell a
chemical. Never smell a gas that is toxic or otherwise
dangerous.
• Use only the chemicals needed for the activity.

• Keep lids closed when a chemical is not being used.
• When diluting an acid, always slowly pour the acid into the
water. Never pour water into an acid,
as this could cause both splashing and/or an explosion.
• Never return excess chemical back to the original bottle. This
can contaminate the chemical sup-
ply.
• Be careful not to interchange lids between different chemical
bottles.
• When pouring a chemical, always hold the lid of the chemical
bottle between your fingers. Never
lay the lid down on a surface. This can contaminate the
chemical supply.
• When using knives or blades, always cut away from yourself.
69
© 2012 eScience Labs, LLC - All rights reserved

68
Lab 4Concepts to ExploreIntroductionNon-renewable Sources•
InkPassive Solar EnergyActive Solar EnergyPhotovoltaicsWind
EnergyExperiment 1: The Effects of Coal
MiningProcedureExperiment 2: Solar
EnergyMaterialsProcedureAppendixA B C© 2012 eScience
Labs, LLC - All rights reserved
Lab 4 – Energy Sources and Alternative Energy
Experiment 1: The Effects of Coal Mining
Table 1: pH of Water Samples
Water Sample
Initial pH
Final pH (24-48 hours)
Pyrite
Activated Carbon
Water
POST LAB QUESTIONS
1. Develop hypotheses predicting the effect of pyrite and coal
on the acidity of water?
a. Pyrite hypothesis =
b. Coal hypothesis =
2. Based on the results of your experiment, would you reject or

accept each hypothesis that you produced in question 1?
Explain how you determined this.
a. Pyrite hypothesis accept/reject =
b. Coal hypothesis accept/reject =
3. Based on your data, what effect do you predict coal mining
has on the environment?
Answer =
4. What can be done to prevent mine drainage from damaging
the ecosystem? Utilize at least one scholarly resource to
support your suggestions.
Answer =
Experiment 2: Solar Energy
Table 2: Solar Energy Experiment Results
Environmental Descriptor/Variable
Observations
(Each should be compared against direct subnlight)
Weather of the Day
Motor speed in direct sunlight
Motor speed at 45 degree angle
Motor speed under reflectors
Motor speed with 25% shaded
Motor speed under red filtration
Motor speed under blue filtration

Motor speed under green filtration
Motor speed under yellow filtration
Post-Lab Questions
1. Develop hypotheses predicting the efficiency of solar energy
from direct sunlight against the 4 variables tested?
Direct vs indirect hypothesis =
Direct vs reflected hypothesis =
Direct vs shaded hypothesis =
Direct vs filtered hypothesis =
2. Based on the results of your experiment, would you reject or
accept each hypothesis that you produced in question 1?
Explain how you determined this.
Direct vs indirect accept/reject =
Direct vs reflected accept/reject =
Direct vs shaded accept/reject =
Direct vs filtered accept/reject =
3. Does increased exposure to the sun’s light produce more
current? Explain how you know this based on your data?
Answer =
4. How could you increase the electricity generated by a solar
cell during the day, when the sun’s angle is constantly
changing?
Answer =
5. Based on your data, could adding filters to solar panels
increase the solar energy produced? Explain how you know

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