Resurrecting the Energy Graveyard: The Potential of Thermoelectricity

Cars mostly use only about 1/4 of their energy to move; the rest becomes emissions, which could be used to generate energy.

Tina Altmanninger cover photo; photo credit: personal
Tina Altmanninger cover photo; photo credit: personal

Tina Altmanninger's Master's thesis at the Johannes Kepler University in Linz explains the process in a way that students can easily understand.

Other processes also generate heat as a waste product, most of which goes unused - a kind of "graveyard" of energy. Given climate change and our ever-increasing demand for electricity, however, it would be smart to make use of this resource. Thermoelectricity could be used to retrieve residual heat from the energy ‘graveyard’ and convert it directly into electricity.

Tina Altmanninger wrote her Master's thesis at the JKU Institute for Theoretical Physics and explained: "All you really need are different kinds of metal wires and a tea candle. Twist the two ends of the wire and bring one of these connections to a higher temperature using the tea candle and watch electricity the flow!" The temperature difference produces what is known as the "Seebeck effect", meaning converting heat directly into electrical energy. Altmanninger added: "This experimental setup, of course, has a low yield."

Although documented as early as 1821, the phenomenon is currently experiencing a rapid revival. The physicist explained: "The two metals are playing tug-of-war, so to speak. Their charges are pulling in opposite directions." Developing new types of materials will result in the charge carriers being responsible for pulling the current together, making the conversion process much more efficient. The process is already being used for space travel, as well as in some of the Earth’s most inaccessible areas.

Altmanninger teaches at the BG/BRG Gmunden, a school that especially supports independent, autonomous learning. She believes: "Forward-looking subjects play an important role in skill-oriented education. There is considerable untapped potential in thermoelectricity for both industrial and private waste heat utilization ". Based on her conviction, she has prepared a cutting-edge, publicly accessible lesson for high school students, educators, and other interested parties, available at:: https://www.geogebra.org/m/d7ttk3he, opens an external URL in a new window.

Altmanninger is one of three finalists for this year’s Macke-Awards, opens an external URL in a new window and on September 21, 2023, she will be one of three award nominees presenting her Master's thesis findings to approximately 200 school students at the JKU’s Circus of Knowledge. The Macke Award is presented annually in recognition of the most outstanding Master’s thesis in the field of physics.