Today's wasted heat could become tomorrow's clean energy

A new type of thermoelectric tube can capture heat from a variety of sources — from hot springs to industrial waste heat — and convert it efficiently into electric power.

Converting heat into energy using thermoelectric technology could prove to be an important source of renewable power.

Conventional thermoelectric generators, however, have complex structures and are restricted to planar shapes, making them difficult to scale up and implement. But a new type of thermoelectric tube from Panasonic could eliminate those limitations.

The new tubes use an unconventional phenomenon called transverse thermoelectric effect, which takes place in a tilted environment featuring multiple layers of thermally-resistive thermoelectric materials and thermally-conductive metals. This effect makes it possible to control heat flow and electric current independently in materials, according to Panasonic.

The tube developed by Panasonic features stacked conical rings of bismuth telluride for the thermoelectric material and nickel for the metal. The power generated depends on variables like the size of the tube and amount of heat source. Panasonic says it’s developed a simulation technology that can optimize the design of the thermoelectric tube to maximize output depending on surrounding conditions.

A 10-centimeter-long tube can generate 1.3 watts of electricity when hot water of 90 degrees C is run on the inside, and cold water of 10 degrees C is run on the outside. Panasonic is now working to develop the system design, optimize manufacturing and study the technology’s feasibility with the goal of being able to produce compact, efficient and economical generators fueled by geothermal energy and waste heat in factories.