Hot and Cold Powered Light - Free Power

This project generates electricity to run a LED light. It is powered from a cold beer can and a heat source.

Here's how it works: A thermoelectric semiconductor is cooled on one side from the coldness of the beer can. This along with a heat source on the other side of the semiconductor, creates electricity which powers the LED light.

Don't be fooled into thinking it's the heat source which is powering the semiconductor because without the cold beer can, the electricity stops being produced in a couple of minutes. With the cold beer, electricity is generated for more than an hour. It will be useful when using a wood burning stove, having an evening BBQ or while camping.

TEG thermoelectric semiconductor

Cold beer can (full)

900 mill empty beer can

5M x 19 counter sunk bolts

Aluminum strip

LED light - garden light

Expandable BBQ fork

Thermal paste

2 empty Beer cans

• Cut a length of 40mm by 3mm aluminum to 17cms long.
• Cut another length as above.
• Drill a hole at each end of the 2 lengths.
• On one of the lengths, counter sinks both holes to hide the head of a counter sunk bolt.

Sandwich the thermoelectric semiconductor between the 2 pieces of aluminum along with a little thermal paste.

Attach the larger 900 mill can to the top of one of the aluminum strips, on the heat side of the sandwiched semiconductor. This will hold the cold beer can in place.

Create a light tower base by:

• Cutting a 60mm length of 10 mm aluminum tubing.
• Cut the handle off the expandable BBQ fork

Attach the base to the 900 ml can using super glue and baking soda.

• Remove the LED unit from a garden light.
• Remove the bottom of 2 beer cans by filing them off, drill a hole the size of the LED in one of the can bottoms.

• Create a bracket using aluminum from a beer can.
• Cut out a template on a piece of paper as shown above and then cut the aluminum the same shape.
• Fit the bracket between the two can bottoms and the arms of the fork.
• Fit in the LED unit with leads going to the outside.
• Glue everything in place, use some tape to hold the assembly together until the glue has dried.

• Solider on leads between the semiconductor and the light unit.
• Fit the light tower into the holder.
• Place a full cold beer can into the larger empty can.

Place the completed unit onto a heat source, such as a frying pan on low heat. After a few seconds, darkness will be transformed into light.

The Beer can light was used while camping. A jaffle iron provided the heat after making some tasty jaffles in the fire. The light was placed on top of the hot jaffle iron. As it was autumn and the evening temperature had fallen down to 5c it was not necessary to place a full beer can inside the larger can to keep the light glowing. I expect in summer a cold can would be required to provide a continuing light.