Solar Race Car

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Alternative Renewable Energy Solar Car Race
Challenge Level 3
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What Youll Learn

• How to design and build a solar powered vehicle
• How to engineer design features to optimize your
  cars performance
• How to determine the best gear ratio for your
  race car

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Stuff Youll Need

• Solar Race Car Kit
• Digital Multimeter
• Measuring Tape
• Duct Tape

Measuring Tape
Tape
Multimeter
Solar Race Car Kit
Alligator Wires
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ePortfolio Suggestions

• Before you begin the activities in this Learning
  Launcher, think about and record what you already
  know about solar powered cars.
• Explain how you decided on your race objectives.
  Be sure to clearly describe each of the rules
  for your race.
• List and explain all the factors (variables) that
  you had to deal with in order to get the best
  possible performance from your solar race car.
• Describe all the things you did while attempting
  to improve your cars performance. What worked
  and what didnt?
• Graph the performance of your car using different
  gear ratios.
• Take a photograph of your final design. Label
  each part and describe how it helped your cars
  performance.
• Create a narrated video of your car in action.

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What You Should Know
What does a glass window and your solar panel
have in common? ANSWER They are both made from
silicon. These lightweight solar cells are like
very thin glass. They are both very brittle and
will shatter quite easily. Therefore, it is your
responsibility to be very careful when handling
your solar panel. Dont drop it or crash your
solar car into things that could cause your solar
panel to shatter.
Shattered Glass
Dont remove the clear tape from the back of the
solar panel. It protects the electrical
connector tabs.
Solar Panel
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What You Should Know
You should already know solar cell fundamentals.
You should know how to connect multiple solar
panels and how to measure voltage output with a
digital multimeter. You should know how the
position of solar panels relative to the sun
affects power output and how to orient them to
maximize performance. If you are not yet familiar
with these concepts, you should consider starting
with a Level I or 2 Learning Launcher.
Solar Panel
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What You Should Know
Your solar powered car will have two gears (at
least). Do you know why? Why do cars and trucks
need gears? Your solar car needs one gear on
the motor shaft and another gear on the axle of
your car. These gears serve two purposes. They
transfer the rotational power from the electric
motor to the wheels of your car. They also
transform that power because the two gears you
will use are not the same diameter. The gear
ratio of any vehicle is critical to its
operation. If a car doesnt have the proper gear
ratio the car wont even move. It will just sit
there.
You will be using gears in many of your SmartLab
projects, so it is helpful to learn more about
them. You can watch this video if you need to
learn more about gears.
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What You Should Know
Determining Gear Ratios
Driver has 10 TeethDriven has 60 Teeth
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Driven60 Teeth
Driver10 Teeth
Motor
Determine the gear ratio of your car using this
formula
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Do It!
The Race is On!
In this activity you will design, build and test
a Solar Powered Race Car! But before you start to
design your car, we need to have some rules for
the race. Rules are like objectives and will
determine how you design your car and how the
race will be conducted. The rules are up to
you! You can design a car to be the fastest over
a certain fixed distance, to reach the highest
top speed, to go the farthest, to climb the
steepest ramp, to pull the heaviest load, etc. Be
creative and think outside the box. Keep in mind
that you will need a way to measure your cars
performance. Before you go on to the next slide,
decide on the rules for your race. Be as specific
as possible and write them down in your Project
Journey Flowchart.
Wins a Tug of War
Carries Heaviest Load
Most Attractive Design
Climbs Steepest Ramp
Fastest Car
Most creative use of Recycled Materials
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Do It!
Solar Powered Race Car Challenge
This collection of parts and some glue or tape is
all you need to build a solar race car. Of
course you will need to use your imagination,
engineering, and research skills to make it a
winning car.
Notice that these parts do not snap together like
LEGOS. Building your solar powered car will take
planning and effort.
Solar Race Car Kit
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Do It!
Solar Powered Race Car Challenge
Make a list of all the design factors that you
believe will effect your cars performance. Then
do your best to make a winning car.
In addition to the science of photovoltaics, you
will need to apply your mechanical engineering
skills to build a high-performance solar race
car. What are some of the things you should
consider?
Gear Ratio
Physics
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Do It!
Solar Powered Race Car Challenge
Once youve thought about how to design the best
car for your race rules, build a test car and
measure its performance. How did it do?
The Basic Chassis
Mounting PV Panel - Wiring
Testing with Flood Lamp
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There are lots of design variables to consider.
Remember that design is often a matter of
trade-offs. Improving one variable can sometimes
detract from another!
Do It!
Optimize your design!
Now think about a few design changes you could
make that would improve your cars
performance. Consider various design variables
and discuss them with your partner. Decide how
to modify your cars design to optimize
performance. Which design factors will improve
your car the most? Now make some improvements
and retest your car!
LIGHT INTENSITY
AERODYNAMICS
GEAR RATIO
WHEEL ALIGNMENT
FRICTION
MOTOR TORQUE
ANGLE to the SUN
LENGTH of WHEEL BASE
ELECTRICAL WIRING
WEIGHT
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Do It!
Solar Powered Race Car Challenge
Make a spreadsheet using Excel to help you keep
track of your test results. The sample
spreadsheet on the right is set up to measure
performance in a specific kind of race. The
format for your spreadsheet will depend on the
rules of your race.
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Extend Yourself
Natural Sun Light versus Artificial Light
Did you test your car inside under artificial
light or outside with natural sunlight? What
difference does the light source have in the
performance of your car? How might you change
your car design to optimize it for one or the
other?
93 Million Miles
Your geographic location has a lot to do with
your chances for BRIGHT sunlight.
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Extend Yourself
Double the Power Challenge
If one is good, would two be twice as good? Try
it and find out. Try connecting two PV panels
together in series. Try connecting them in
parallel. What works best? How much will this
increase your speed and power. Can you make a
hill-climbing low geared vehicle? Be creative!
Try lots of different ideas!
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Two photovoltaic panels with three cells each
connected in series
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Extend Yourself
Alternate Materials Challenge
Is it possible to use other materials available
in your SmartLab to build a new race car or
improve your cars performance? Do some
brainstorming and come up with a plan. Present
your plan to your SmartLab facilitator for
approval and then give it a try!
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Extend Yourself
Students, scientists and engineers all over the
world are hard at work on solar race car designs.
There are lots of organized races at many levels
of competition. Do an online search for solar car
races to discover more about the latest
developments in races and solar race car designs.