An Emergency Light of Ice and Fire
It has absolutely nothing to do with Game of Thrones, but this DIY lets you harness the power of the elements during times of emergency. Perfect preparation as winter is coming.
Joohansson posted an Instructable of an emergency light made from two tin cans, some tea light candles, water, a simple USB reading light, and a thermoelectric generator (TEG) module. TEG modules can be purchased online and can be used for a variety of science projects.
The basic principle of a TEG module is that it can convert heat energy into electrical energy. In this emergency light setup, Joohansson had to create chambers that have notable differences in temperature. It is the temperature gradient that creates the electrical energy. This is known as the Seebeck effect.
Joohansson’s emergency light uses heat (from three tea light candles) on the bottom chamber with the TEG module above it. On top of the TEG module is a chamber with a colder substance, like water. The TEG module then detects the temperature difference between the hot candles and the water, and a small amount of electricity is produced. He was able to brighten up a small LED reading light with his project.
Other variations of this set up used a gas burner at the bottom as the heat source. The advantage of this is that the water temperature can reach above that of the tea light candles. Joohansson was able to generate enough power to charge his iPhone 4S with this system. Again, he stresses that you should ensure that your set-up can tolerate such temperatures before attempting to plug in any electronic device.
If you don’t have a constant heat source like candles or a gas burner, then you can use hot water on the bottom. Instead of using tepid water on the top chamber, you can fill it up with ice cubes. Joohansson says this setup is enough to power a small LED reading light for about 30 minutes.
Via Tree Hugger