Our paper entitled: Exploring the potential for waste heat recovery during metal casting with thermoelectric generators: On-site experiments and mathematical modeling has been accepted for publication in Energy. Since casting of metals like silicon occurs at a very high temperature (about 1750 K), much heat disappears into the surroundings by radiation. Thermoelectric generators are scalable and simple systems that can be used to convert heat to electrical power by exploiting the coupling between transport of heat and electrical charge. In our work, we combined on-site measurements at Elkems silicon casting plant at Salten in Norway (see picture below) and a mathematical model to study the potential for power generation with this technology from heat available during casting of silicon.
We implemented a bismuth-tellurium based thermoelectric generator in the casting area of a silicon plant. The measured peak power was 160 W/m2, however, we predicted a large potential to increase the power generated beyond the measured values. One of the main findings was the concept of “less for more”, where a higher power output could be obtained by using fewer thermoelectric modules per surface area. This work is the first in an ongoing effort to understand the potential of thermoelectric generators in recovering waste heat, and how to optimize their performance. The work was performed in in collaboration with Marit B. Takla, Odne S. Burheim and Signe Kjelstrup from NTNU.