Use a citrus fruit to generate electricity to turn on a Light Bulb
Don't have a battery? Try using a lemon, lime or grapefruit.

Here is what you need:

A lemon, lime or a grapefruit
A copper nail, screw or wire (about 2" or 5 cm long)
A zinc nail or screw or galvanized nail (about 2" or 5 cm long)
A Christmas light with 2" or 5 cm leads (enough wire to connect between the two nails)

1. Set the fruit on a table and gently roll it around to soften it up. You want the juice to be flowing inside the fruit without breaking its skin. Alternatively, you can squeeze the fruit with your hands.

2. Insert the zinc and copper nails into the fruit so that they are about 2" or 5 cm apart. You don't want them to be touching each other. Avoid puncturing through the end of the fruit.

3. Remove enough insulation from the leads of the light bulb (about 1") so that you can wrap one lead around the zinc nail and one lead around the copper nail. If you like, you can use electrical tape or alligator clips to keep the wire from falling off the nails.

4. When you connect the second nail, the light will turn on!

This would be a great science fair project for a Elementary School student.

Millet

I've done this a number of times before, actually last year I did it with a poncirus fruit. It gave electricity for a month or so before it dried out too much.


I'm not sure about the Christmas light bulb though (incandescent) that would draw quite a bit of current opposed to an LED.

One lemon with a piece of copper wire and a galvanized nail should have enough power to run an old LCD watch though.