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Making Solar Energy With a Sun Lamp for a Science Experiment

Solar energy produces no greenhouse gases, it is reliable and durable, and its fuel is free. On the other hand, it is only about 10 percent efficient, and it requires very precise, multiple-step manufacturing, making the capital cost relatively high. The more young minds become interested in addressing the technology of solar energy, the more likely it is that solar energy equipment will become more efficient and inexpensive to produce, and some simple science experiments can drive that interest.

Things You'll Need

Sun Lamp
Photovoltaic Cells (solar cells)
Wooden board
Resistors
Ammeters
Cellophane, different color sheets
Tape measure

Instructions

- 1
  Attach your photovoltaic cell to a wooden board. If you have several photovoltaic cells, you can mount them all side by side on the same board. Make sure you have access to the two leads from the cell.
- 2
  Connect one lead to one lead of the resistor. The resistor simulates the load. The current and voltage of the solar cell change depending upon how large the load is. A 5- or 10-ohm resistor might be a good choice, but you can choose any resistor that gives you an amount of current that is easily measurable with your ammeter.
- 3
  Connect an ammeter between the other lead of the resistor and the other lead of the photovoltaic cell. The ammeter will measure the current put out by your solar cell. If you have a single ammeter for multiple cells, just put the leads where they will be accessible as you move the ammeter from cell to cell. If you have a small panel ammeter for each cell, attach it next to the cell.
- 4
  
  You can use an inexpensive panel meter to monitor the performance of your solar cells.
  
  Point the sun lamp at the solar cells and measure the current. Square the measured current value and multiply it by the value of the resistor to get the amount of power generated by the solar cell.
- 5
  Measure the distance from the photovoltaic cells to the sun lamp. Change the distance, and repeat the measurements from the previous step. This represents how sunlight spreads with distance from the sun, meaning the solar flux is lower on Mars than it is on Earth, for example.
- 6
  Change the angle of the board with respect to the light from the sun lamp and repeat the measurement of Step 4. This is a measure of how the power from a solar cell changes as the sun crosses the sky.
- 7
  Place different color pieces of cellophane in front of the solar cells and measure the power as in Step 4. This is an indication of which colors are converted more efficiently by the solar cell.

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