Optimized thermoelectric generation for efficient low-medium temperature geothermal energy harvesting

Abstract

This paper aims to design and evaluate a thermoelectric generation system optimized for low-to-medium temperature geothermal energy, focusing on maximizing power output and system efficiency. A one-dimensional mathematical model based on energy balance is employed for a single thermoelectric element and subsequently scaled to a 600 thermoelectric generators (TEGs) module. The Peltier, Fourier, and Joule heating effects are included in the analysis, whereas the radiation and convection effects are neglected. The impact of various 2D and 3D layouts of thermoelectric generators (TEGs) and temperature variations on power generation and performance is examined. An experiment is performed to observe the power capacity of a module consisting of five thermoelectric generators. These experimental observations validate the analytical model, and reference properties are adopted to predict more complex modules. This work aims to simulate the optimal design of a TEG module, utilizing the temperature difference to generate 1 kW of power. For this purpose, a module comprising of 600 TEGs is analyzed in various layouts. Based on experimental results for the temperature difference $\Delta T=96.4{}^{o}C$, it is proposed that a compact module consisting of 600 TEGs with a 3D design of 10 × 12 × 5 will be suitable and cost-effective to generate 1 kW power.