How to Make Solar Energy for One Light Bulb

Making a battery-powered clock from a lemon is an old hat science project. Building a homemade solar cell than can run a small light bulb has a lot more panache. Following this guide will show you how to do just that, using nothing more than some copper sheeting, your kitchen stove, and a few common parts and tools.

Things You'll Need

• Sheet metal sheers
• Corrosion-free copper sheeting
• All-metal thongs
• Gas burner
• Plastic scouring pad
• Electrical alligator clips with wiring.
• Clear jar
• Salt

Instructions

1. Examine the copper sheeting thoroughly for signs of corrosion. If there are any, either do not use those parts of the sheeting, or clean them before using them.

2. Use the sheet metal sheers to cut two rectangular strips from the copper sheeting. These need to fit into the jar without touching.

3. 

   Switch the burner to its highest setting and use it to heat one of the copper strips to red hot. A layer of black oxide should form on the top. When this is done, remove it with the tongs and let it cool for at least 20 minutes.

4. Scrape the black oxide off by gently using the plastic scouring pad. Take care to not remove any of the reddish-pink oxide underneath.

5. Insert the both the "cooked" and "uncooked" strip into the jar, so that they bend to conform to the jar's curvature. This should be easy, as copper is very malleable.

6. Clip the alligator clips on. The black, negative clip goes to the "cooked" strip, and the red, positive clip goes to the "uncooked" strip.

7. Run the wiring from the clips to the light fixture and attach them.

8. 

   Mix a salt water solution. Use warm water, and stir in salt until the salt stops dissolving. This will create a supersaturated solution.

9. Fill the jar up about two-thirds of the way.

10. Place the jar in full sunlight. Under those conditions, it should produce enough power to light a 10 watt bulb.

Resources

• Scitoys: Copper and Salt Solar Cells
• A Different Copper-based Cell Design