Download Project
Issue
What direction should solar panels face, as well as why?
Materials
Magnetic compass
Empty tissue container
Marker
Pen and paper
4 outdoor/indoor thermometers
Sun-drenched day
Sand (or another form of weight)
Mp3
Plastic wrap
Procedure
Fill your empty cells box with sand.
Tape each of the four thermometers towards the tissue box, one to each side, with the bottoms facing the same direction.
Tape a layer of plastic wrap over each thermometer utilizing a square of equal size for all of them. What do you think the Plastic Wrap is perfect for?
Solar Diagram
Find a spot outside you know will get sunlight all day.
Try to wake up before the sun rises to be able to place your tissue box in this place. Use your compass to find north, and rotate one side of the tissue box to face that direction. Label this side by having an ‘N, ’ and make sure to the rest of the sides with their corresponding directions on the actual compass. Do you think the sun rises straight to the east and sets directly in the actual west? Why or why not?After the sun's rays begin to rise, wait half an hour and consider the temperature for each thermometer. Record the time for every thermometer in a chart like this:
Do this after every hour during the period of the day, until late in the morning (or until sunset, if you can wait around that long! ).
Collect your tissue box and create a graph of temperatures using the data a person collected. What’s the difference between the greatest and lowest temperature thermometers? Is this surprising for you? Are the temperatures the same at beginning and sunset?
Results
What data you get is determined by your latitude and what time of year it's, but if you’re in the United States you need to see a higher overall temperature on the thermometer that faced south compared to the thermometer that faced north. Someone in the southern hemisphere would visit a higher temperature on the thermometer facing northern.
Why?
Your building manager was wrong. The sun's rays feel warmer in the afternoon just because everything is hotter within the afternoon—after all, everything has had ample time for you to warm up all day! It turns out that regardless of how far north or south the sunlight is, it’s always somewhere in the southern the main sky all day, and it doesn’t rise or set directly within the east or west, respectively (except at special times of year in special places about the Earth). So how come?
The earth is tilted in accordance with its orbit around the Sun. When the actual northern hemisphere is enjoying its summer, our planet tilts that hemisphere towards the sun. For this reason, the sun appears higher in the sky throughout the summer months. It’s winter in the southern hemisphere throughout the northern hemisphere’s summer, because during this period, the southern hemisphere is tilted away in the sun.
If you live north of the actual Tropic of Cancer, the sun will continually be in the southern half of the skies. Because the Earth tilts in different directions during the period of a year, the sun’s apparent position appears to wander from places directly above the Tropic associated with Cancer to places directly above the Tropic of Capricorn and back—but since the sun is almost always in the south from the sky in the northern hemisphere, it may preferentially illuminate south-facing objects, such as buildings or solar power panels. A good rule of thumb is to tilt your solar power panels south towards the sun (and if you wish to get really picky, tilt them at an angle determined both by what lengths north you are and the balance of one's you want during the summer and winter season months).
So what’s the deal with covering our thermometers in plastic? The plastic cover traps heat, allowing the sunlight hitting the whole face of t
he tissue box to the warmth that face’s thermometer. It behaves like the greenhouse: light from the sun passes through the transparent material and heats up anything beneath it. That heat can’t pass back through the actual material and escape. This allows us to determine a bigger change in temperature, which makes our data easier to interpret.
