How do Solar Cells Work

You must all have heard about the term "solar cell"? It is something you use everyday when you handle such devices as electronic calculators and solar water heaters. Each of this devices contain solar cells in them. But what is this "solar cell"? How does it work?

A solar cell or photovoltaic cell is actually a device that converts solar energy(the energy of sunlight) into electricity by the photovoltaic effect. But what is photovoltaic effect? It is actually a technique by which electricity is produced as voltage by a nonhomogeneous semiconductor, such as silicon, by the absorption of light or other electromagnetic radiation.

Solar cells are used for different purposes. While individual cells are used for powering small devices such as electronic calculators, photovoltaic arrays(which are made of multiple interconnected solar cells) are used in Earth-orbiting satellites, remote radiotelephones, water pumping applications and even to generate a form of renewable electricity in remote areas where it is impossible to provide electric power from the grid in the normal way.

Photovoltaics is the field of technology and research related to the application of solar cells as solar energy.

With a simple science project, you can find out for yourself how solar cells work and also the effects of different wavelengths of light on solar cells. This experiment will help you predict which wavelength of light will cause the least or most disturbance in the production of electricity by your solar cell.

Materials needed:
1) Solar car model
2) Colored transparency sheets
3) Cardboard
4) Scissors
5) Black marker
6) Wooden blocks (or something to prevent your car wheels from touching the ground)
7) Tape
8) Stopwatch

What to do:

1) Gather all the materials required for your experiment.

2) Assemble your solar car according to the instructions provided on your kit.

3) Cut a circular piece out of the cardboard you have. Tape it to the face of one of the wheels on your car.

4) Make a dot on the edge of the cardboard circle with the black marker. This will help you to measure the speed at which the wheel spins.

5) Place your car in bright sunlight on blocks. See that the solar cell gets plenty of light.

6) Switch the power source to solar power depending on the model of the car.

7) Watch the spinning wheel and the dot on the cardboard circle.

8) Start your stopwatch and count the number of times the dot rotates in 15 seconds. Multiply this number by 4. This will give you the number of rotations in a minute. Record your observations.

9) Repeat step 5, only this time you have to cover the solar cell with one of the colored transparency sheets.

10) Repeat steps 6, 7, 8 and 9.

11) Repeat steps 10 and 11 with the rest of the colored transparency sheets.

12) Repeat this experiment two more times. Compare the results. Graph and chart your data. Describe how covering the solar cell affected the spinning of the wheel.

Conclusion:
Write down in brief the results of your solar science projects experiment. Explain patterns in your data. Write whether or not your data supported your hypothesis. If not, explain the reasons. Evaluate your project and make suggestions for improvements.

NOTE: Adult supervision is recommended.

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