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Lekbir et al. Energy Mater. 2025, 5, 500101 https://dx.doi.org/10.20517/energymater.2025.46 Page 3 of 17

minimizing environmental impact.

Contributions of this study
Upon reviewing the existing literature, it is clear that most published works have primarily focused on
enhancing the performance of TEG modules by integrating different types of materials. However, only a
limited number of studies have examined their environmental impacts despite this being a critical aspect of
any renewable technology. Moreover, most studies on the environmental impact of different TEG materials
consider TEG modules of similar sizes, typically referring to commercial TEG modules. Additionally,
research investigating the environmental impact of TEG materials throughout their production phases,
including raw material supply, transportation to the manufacturing site, and final material fabrication, often
lacks sufficient data, particularly for the latter two stages. This limitation arises because different TEG raw
materials require distinct processing equipment and varying energy inputs for transformation and
manufacturing, leading to non-generalizable results and making comparative studies impractical.
Furthermore, most existing studies focus either on material selection or geometric optimization, often
neglecting a holistic approach that integrates both aspects through innovative multi-objective optimization.
Moreover, the trade-offs between environmental benefits and performance efficiency remain insufficiently
explored. This study presents a comprehensive approach to TEG module design to address these gaps by
integrating performance assessment with environmental impact evaluation. Specifically, the optimization of
TEG system geometry is conducted using particle swarm optimization (PSO)-based multi-objective
optimization to simultaneously maximize power output and minimize environmental impact. By refining
design parameters, this approach enhances efficiency while reducing material-related emissions, paving the
way for next-generation TEG modules that are both high-performing and sustainable. Overall, the findings
provide valuable insights for researchers, policymakers, and industry professionals seeking to improve the
sustainability and efficiency of thermoelectric energy conversion systems.

METHODS
This study investigates the performance and environmental impact of various TEGs. The analysis is based
on the geometry of commercially available TEGs and the different types of TEG materials commonly used
in previous research. While the input parameters are derived from experimentally validated data reported in
the literature, this study employs a novel computational framework to generate new insights. Specifically,
the methodology involves advanced modeling, performance optimization, and environmental impact
assessment, which extend beyond the scope of the original experimental studies. By leveraging validated
data, this approach enables a comprehensive evaluation of TEG materials and designs without the need for
additional experimental validation, ensuring both reliability and the generation of original findings.

In this context, Several assumptions have been considered to achieve the main objectives of the present
study. These assumptions are outlined as follows:

1. A temperature difference of 30 K is assumed. This value is a realistic and conservative estimate for low-
grade waste heat recovery system applications.

2. The TEG module is assumed to have a 20-year operational lifespan. This is justified by the high durability
and absence of moving parts in TEG systems, which align with the typical lifespan of photovoltaic (PV)
systems.

3. TEG systems are solid-state devices that require negligible maintenance due to the absence of mechanical
components or moving parts. This aligns with standard assumptions for long-term applications of solid-