The Power of the Sun

An inquiry into using the Sun’s energy for power.

Presented by Emily WeilFall 2009

The Sun’s Heat

1) How can we use the Sun’s energy instead of what we currently use?

2) How do we already use it?

• These questions came up as I performed a temperature change experiment relating to light and colors.– The results of the experiment were that Black objects

absorb heat, and light, at a faster rate than White objects do. • This is due to white reflecting all of the colors and black absorbing

them

Applying Knowledge

• I wanted to apply what I learned from that experiment to a real-life idea.

• While exploring the experiment, I came across the idea of solar-powered pizza box ovens.

• First of all, what is solar power, and what concepts are connected to it?

Solar Power

• Solar power is the creation of electricity from sunlight. – There are two methods of using solar power:

• 1) Directly through photovoltaics (PVs) • 2) Indirectly through using solar energy to boil water, which in

turn, generates electricity.

• From another experiment, I discovered that black absorbs much more of the sun’s, or light, energy than other colors.– Therefore, to create more heat, I will make my solar oven

black.– Another idea to consider: What material holds heat the best?

• Hypothesis: Metallic substances are the best insulators, or heat conductors.

Find a cardboard box to use:(Pizza box preferred)

Tape/Glue Aluminum Foil to the Flap (This is what will catch the sun’s light)

Put aluminum foil inside the box for heat insulation. (Try different amounts to see what

holds heat the best, and maybe different insulation materials)

I put black construction paper to attract more

heat/light.Question: Will more black

attract more heat?How to answer: Make more than one oven of same size and use different amounts

of black on each.Another idea to try could be the method of putting black on the oven. Therefore, I put black construction paper on

one and black paint on another (same amount of

black)

Cover different amounts of the box with black so that it more easily absorbs the sun’s heat/light!

Results:Oven Design: All Black Paint All Black Paper Partially Black Paper

After 20 minutes Frozen Frozen Frozen

After 30 minutes Partially frozen Partially frozen Frozen

After 1 hour Warm Warm Partially frozen

After 2 hours Cheese melted Cheese melted Warm

Notes: The tacos were supposed to take 15 minutes to cook in a regular oven at 400 degrees Fahrenheit.

The solar-powered ovens were supposed to take at least double the time. However, they took much longer than double the usual time (this may be due to the high level of heat required in the regular oven)

Thoughts:

• I was really disappointed with how the solar-powered oven performed, but I’m not giving up yet!

• It needs to be determined whether other factors were involved:– 1) Did the temperature of the room affect the performance

of the oven?– 2) Would this work better during a different time of the

year?– 3) Would this be affected by the amount of clouds in the

sky?– 4) Does the time of day come into play?

Here’s a Possible Continuation:

• Create a larger reflector to catch more of the sun’s light rays.

• Use a different insulator than aluminum foil.

• Test different sizes of boxes

Resources

• Wikipedia :– (solar energy pictures and definition)

• http://tonto.eia.doe.gov/kids/– (solar-powered oven experiment and solar power

information for kids)