This is a thermoelectric tube based on a new structure, which can generate electricity using temperature difference alone.
This world-first development, made by Panasonic, means that if these thermoelectric tubes are used for piping hot water, electricity could be generated using the piping itself.
“This is a thermoelectric tube. It’s about 10 cm long. This generator unit contains four of these tubes. Hot water is passed through the tubes, and the outside is cooled using cold water. This four-tube unit generates about 10 W, which can power a fan, an LED light, or a portable TV.”
Until now, thermoelectric generation has been prone to high loss when heat is taken in, because thermoelectric elements have been attached and connected to the outside of pipes. Such systems have also had issues with reliability.
“By making the product tubular, we’ve enabled it to take in more heat with the same size. As a result, the power output is three or four times higher than with conventional systems. A feature of this product is, you can generate electricity simply by replacing existing hot-water pipes with these.”
The thermoelectric tube has a simple structure, with thermoelectric material, which has low thermal conductivity, and metal components, which have high thermal conductivity, stacked at an angle.
“Having the components at an angle means the direction of heat flow is perpendicular to the electric current. So, heat flows from inside the tube to outside, but the current flows along the length of the tube.”
In the future, compact, efficient, and economical electricity generators fueled by factory waste heat or geothermal springs will become possible.
“To make this product practical, we need to manufacture the tubes efficiently, and to make them easily installable in various locations. We aim to produce a commercial version in 2018.”