Thermoelectric Generation Applications Research Articles

First-principles studies of the structural, mechanical, electronic, magnetic and transport properties of inner transition based RaMO3 perovskites (M = Cm, Bk)

In the quest for new materials, we introduce self-consistent ab initio simulations to investigate the structural and mechanical stability, electronic profile, and transport properties of f-electron-based RaMO3 (M = Cm, Bk) perovskites by employing density functional theory. The energy optimization indicates that these alloys exhibit stability in the ferromagnetic phase. The examination of mechanical parameters demonstrates the ductile nature of these materials. To elucidate the electronic structure of these alloys, we employed a combination of two approximations: Generalized Gradient Approximation (GGA) and GGA + mBJ. Both approximations confirm the alloys’ half-metallic character. The magnetic moments calculated using both approximations were approximately 6 µB for RaCmO3 and approximately 7 µB for RaBkO3. The thermoelectric performance of these materials is evaluated by investigating different transport parameters such as the Seebeck coefficient, electrical and thermal conductivity and power factor. The comprehensive investigation of these two alloys has the potential to expand their applications in spintronics, thermoelectric devices, and radioisotope thermoelectric generators (RTGs).

Screen printing Ag2Se/carbon nanocomposite films for flexible thermoelectric applications

Flexible thermoelectric generators offer the possibility of harvesting waste heat from the human body. However, intrinsic brittleness and the high production cost of bulk thermoelectric materials limit their applications in flexible thermoelectric generators. Herein, flexible Ag2Se/carbon nanocomposite films on polyimide substrates are prepared by scalable screen-printing followed by facial heat treatment. An optimal film shows a maximum power factor of 1617 μW m-1 K-2 at room temperature and good flexibility. The film consists of mainly Ag2Se grains with a preferred (00Ɩ)-orientation and a small amount of carbon. Microstructure observations reveal that the Ag2Se grains with sizes of nano to micrometers have coherent or continuous grain boundaries, and the carbon is mainly amorphous with slight graphitization. A flexible thermoelectric device assembled with the optimal film exhibits a power density of 29.1 W/m2 at a temperature gradient of 35.4 K. This work demonstrates a cost-effective route to high-performance flexible thermoelectric films.

Critical analysis of enhanced photovoltaic thermal systems: a comparative experimental study of PCM, TEG, and nanofluid applications

Phase change materials (PCM), thermoelectric generators (TEG), and nanofluids are popular methods investigated for improving conventional photovoltaic thermal (PVT) systems. These methods are particularly used in warm climates where high temperatures negatively impact photovoltaic (PV) power output and energy efficiency. This experimental study evaluated the effects of 32 °C melting point PCM and TEG integration on PVT units, as well as 42 °C melting point PCM and nanofluid incorporation on concentrated PVT (CPVT) units. Technical, exergetic, and economic performance were compared using a small-scale PVT module. Low-cost commercially available materials were used to construct all PVT units. Industrial metal waste was introduced to enhance the thermal conductivity of paraffin wax and salt hydrate PCMs. The results indicated that applying PCMs, porous media, and concentrator plates increased energy generation, potentially offsetting their higher initial cost and achieving an energy cost of approximately $0.135/kWh. However, TEG and nanofluid implementation remained uneconomical, leading to a 15–35 % increase in energy cost. The water-based CPVT unit, enhanced with paraffin wax and copper fins, demonstrated the best technical performance. This unit achieved electrical, thermal, and exergy efficiencies of approximately 15.5 %, 37.4 %, and 16.7 %, respectively, with more than a 20 % reduction in cell temperature. The study also revealed that severe structural changes caused by corrosion of metallic materials in hydrated PCMs could alter the melting point by more than 30 %. This change negatively impacts heat storage capacity. Conversely, incorporating metal chips in non-hydrated PCMs improved the time to reach the melting point state by 30–60 minutes.

Hybrid silver-graphene nanoparticles enhanced Lauric Acid phase change material for photovoltaic and thermoelectric generator applications: Experimental and simulation analysis

The global initiatives for renewable energy promote sustainable energy technologies such as photovoltaic thermal (PVT) systems and thermoelectric generators (TEGs). Latent heat energy storage is an effective method for conserving excess thermal energy and can be applied to PVT and TEG technologies. The fatty acid phase change materials (PCMs) are appealing, but their low thermal conductivity limits their practical usage. In this study, silver (Ag) and graphene (Gr) hybrid nanoparticles (NPs) are considered as additives to augment thermo-physical properties of lauric acid (LA) PCM for implementation in PVT and TEG applications. The nanocomposites are prepared by two-step technique. Additionally, implementation of composites in PVT has been evaluated experimentally and through TRNSYS simulation. Besides, composites impact on TEG application was assessed experimentally. As per results, photo-absorption analysis; nanocomposite LAG-3.5 (LA with 3.5 % hybrid Ag and Gr NPs) displayed the highest 76 % decrease in transmissibility. In addition, LAG-3.5 nanocomposite augmented thermal conductivity of LA by 57 % due to integration of high thermally conductive hybrid NPs. Further, LAG-3.5 composite reported an 8 % increment in latent heat enthalpy. As per reliability, after 500 thermal cycles, nanocomposite LAG-3.5 showed chemical stability and thermal durability. Moreover, optimal composite LAG-3.5 exhibited enhanced electrical characteristics while implementing in photovoltaic and thermoelectric generator application. Therefore, the nano-enhanced composite can be significant application prospects in the 45 °C to 50 °C melting temperature range.

Heavy elemental compound addition enhancing thermoelectric performance of Chromium Silicide synthesized by Spark plasma sintering

Silicide-based materials drive great potential in developing mid-temperature range thermoelectric generators (TEGs) applications. However, realizing the efficient and stable silicide materials is still a constraint for its real potential device applications. Chromium silicide will likely become p-type thermoelectric materials in this direction for thermoelectric power generation applications. However, high thermal conductivity values impede the figure-of-merit (zT). The present work adopts the chromium silicide, adding different weight percentages of well-known ZrCoSbSn compounds employing the compaction spark plasma sintering (SPS) technique. By adopting these combinations, the thermal conductivity is significantly reduced by enhanced scattering of heat-carrying phonons by multiple interfaces. Also, the maximum power factor value of ≃ 2.1 × 10−3 W/mK2 is achieved by employing a CrSi2 -ZrCoSbSn compound addition. The enhanced figure-of-merit value (zT) ≃ 0.26 is realized in the temperature at 623 K for the CrSi2-5wt% ZrCoSbSn compound material.

Enhancing Bi2Te2.70Se0.30 Thermoelectric Module Performance through COMSOL Simulations

This research employs the COMSOL Multiphysics software (COMSOL 6.2) to conduct rigorous simulations and assess the performance of a thermoelectric module (TEM) meticulously crafted with alumina (Al2O3), copper (Cu), and Bi2Te2.70Se0.30 thermoelectric (TE) materials. The specific focus is on evaluating diverse aspects of the Bi2Te2.70Se0.30 thermoelectric generator (TEG). The TEM design incorporates Bi2Te2.70Se0.30 for TE legs of the p- and n-type positioned among the Cu layers, Cu as the electrical conductor, and Al2O3 serving as an electrical insulator between the top and bottom layers. A thorough investigation is conducted into critical parameters within the TEM, which include arc length, electric potential, normalized current density, temperature gradient, total heat source, and total net energy rate. The geometric configuration of the square-shaped Bi2Te2.70Se0.30 TEM, measuring 1 mm × 1 mm × 2.5 mm with a 0.25 mm Al2O3 thickness and a 0.125 mm Cu thickness, is scrutinized. This study delves into the transport phenomena of TE devices, exploring the impacts of the Seebeck coefficient (S), thermal conductivity (k), and electrical conductivity (σ) on the temperature differential across the leg geometry. Modeling studies underscore the substantial influence of S = ±2.41 × 10−3 V/K, revealing improved thermal conductivity and decreased electrical conductivity at lower temperatures. The findings highlight the Bi2Te2.70Se0.30 TEM’s high potential for TEG applications, offering valuable insights into design and performance considerations crucial for advancing TE technology.

Innovative design for thermoelectric power generation: Two-stage thermoelectric generator with variable twist ratio twisted tapes optimizing maximum output

In recent years, considerable effort has been dedicated to the development of highly efficient thermoelectric generators for waste heat recovery and thermoelectric power generation. In this study, we present employing twisted tapes with variable twist ratio to enhance thermal energy extraction efficiency, coupled with two-stage thermoelectric modules for heat-to-electricity conversion, resulting in a substantial increase in the power output of the thermoelectric generator. We established an experimental system that validated the superior power generation and heat recovery characteristics of the two-stage thermoelectric generator. Building upon these findings, we propose further optimizing the variable twist ratio twisted tapes to enhance the power output. We investigated the impact of tape pitch ratio, twist ratio, and twist ratio variation range on thermoelectric performance. Experimental results indicate that the influence of flow instability is more pronounced than that of swirl intensity, and twist tapes with the maximum twist ratio variation rate yield the highest net output power. Compared to an unmodified thermoelectric generator, the two-stage thermoelectric generator employing twist tapes with a twist ratio increase from π to 3π achieves a maximum net output power gain of up to 100%. These findings provide a practical framework for integrating innovative power generation modules and optimized heat exchanger designs into the application of waste heat recovery thermoelectric generators, marking a significant advancement in the field of thermoelectric generators.

High-Entropy Photothermal Materials.

High-entropy (HE) materials, celebrated for their extraordinary chemical and physical properties, have garnered increasing attention for their broad applications across diverse disciplines. The expansive compositional range of these materials allows for nuanced tuning of their properties and innovative structural designs. Recent advances have been centered on their versatile photothermal conversion capabilities, effective across the full solar spectrum (300-2500nm). The HE effect, coupled with hysteresis diffusion, imparts these materials with desirable thermal and chemical stability. These attributes position HE materials as a revolutionary alternative to traditional photothermal materials, signifying a transformative shift in photothermal technology. This review delivers a comprehensive summary of the current state of knowledge regarding HE photothermal materials, emphasizing the intricate relationship between their compositions, structures, light-absorbing mechanisms, and optical properties. Furthermore, the review outlines the notable advances in HE photothermal materials, emphasizing their contributions to areas, such as solar water evaporation, personal thermal management, solar thermoelectric generation, catalysis, and biomedical applications. The review culminates in presenting a roadmap that outlines prospective directions for future research in this burgeoning field, and also outlines fruitful ways to develop advanced HE photothermal materials and to expand their promising applications.

A Rolled Organic Thermoelectric Generator with High Thermocouple Density

AbstractThe surge in the number of distributed microelectronics and sensors requires versatile, scalable, and affordable power sources. Heat‐harvesting organic thermoelectric generators (TEGs) are regarded as potential key components of the future energy landscape. Recent advances in the performance of organic thermoelectric materials have made practical applications of organic TEGs more feasible than ever before, yet the challenges of designing and fabricating organic TEGs suitable for real scenarios are scarcely addressed. Specifically, small sensors and wearables demand for micro‐thermoelectric generators (µTEGs) with high power density architectures and small form factors, while typical demonstrations of organic TEGs are characterized by < 10 thermocouples (TCs) per cm2. This work presents a rolled, organic µTEG architecture combining large‐area, solution‐based deposition techniques, such as inkjet and spray‐coating, and an ultrathin parylene substrate to achieve a thermocouple density of 1842 TCs cm−2. Such demonstrative µTEG reaches a thermoelectric conversion performance of 0.15 µW cm−2 at ΔT = 50 K. Such power output is well in line with finite element method simulations, which highlight the benefit of the architecture and show that remarkable power densities, in the mW cm−2 range at ΔT = 10 K, are realistically achievable with geometrical improvements and already ongoing advancements in organic thermoelectric inks.

Advancements in Thermoelectric Generator Design: Exploring Heat Exchanger Efficiency and Material Properties

This paper presents a comprehensive study on the application and optimization of automotive thermoelectric generators (ATEGs), focusing on the crucial role of heat exchangers in enhancing energy conversion efficiency. Recognizing the substantial waste of thermal energy in internal combustion engines, our research delves into the potential of TEGs to convert engine waste heat into electrical energy, thereby improving fuel efficiency and reducing environmental impact. We meticulously analyze various heat exchanger designs, assessing their influence on the TEG’s output power under different exhaust gas flow rates and temperatures. Furthermore, we explore the impact of TEG material properties on the overall energy conversion effectiveness. Our findings reveal that specific heat exchanger designs significantly enhance the efficiency of waste gas heat exchange, leading to an improved performance of the TEG system. We also highlight the importance of thermal insulation in maximizing TEG output. This study not only contributes to the ongoing efforts to develop more sustainable and efficient vehicles but also provides valuable insights into the practical application of thermoelectric technology in automotive engineering. Through this research, we aim to pave the way for more environmentally friendly transportation solutions, aligning with global efforts to reduce fossil fuel dependence and mitigate environmental pollution.

Optoelectronic and thermoelectric properties of novel double halide perovskites Na2AgAsX6 (X = Cl, Br) for efficient green solar cells

Inorganic lead-free double halide perovskites have emerged as promising materials in photovoltaic and renewable energy applications. This study investigates the optoelectronic and thermoelectric properties of novel inorganic lead-free double halide perovskite Na2AgAsX6 (X = Cl, Br) materials using accurate PBEsol and nKTB-mBJ schemes within the powerful full potential linear augmented plane wave (FP-LAPW) method. Structural ground state parameters were optimized, and the structural stability of these materials was assessed by evaluating their formation energy, phonon frequencies, and tolerance factor. Analysis of the electronic structure reveals that Na2AgAsX6 exhibit an indirect gap character, with energy values of 2.0 (for Cl) and 1.29 eV (for Br). Additionally, we computed various optical properties including dielectric functions (ε1, ε2), absorption coefficient (α), refractive index (n), extinction coefficient (k), and reflectivity (R), demonstrating a broad absorption spectrum spanning from visible to ultraviolet wavelengths. Furthermore, the investigation extends to determine the electronic transport properties—Seebeck coefficient (S), electrical conductivity (σ/τ), power factor (PF), thermal conductivity (κe/τ), and figure of merit (ZT) for Na2AgAsX6 (X = Cl, Br), using BoltzTraP code. These findings underscore the substantial potential of Na2AgAsX6 (X = Cl, Br) halide perovskites as efficient light absorption layers in the development of high-performance perovskite solar cells (PCSs) and also hold promise for future eco-friendly thermoelectric generator applications.

Insight into the structural, elastic, phonon dispersions, and optoelectronic properties of Cs2YXCl6 (X = In, Tl) double perovskites for solar cells and energy conversion applications

Due to their lack of lead, stability, and outstanding performance, double perovskites have emerged as a prominent subject of study in solar cell research. Thus, we present an analysis of the structural, elastic, electronic, and optical characteristics of Cs2YXCl6 (X = In, Tl) with regard to their applications in solar cells and thermoelectric generators. The structural stability has been validated by observing the thermodynamic stability, as evidenced by the negative formation energy and the fitting of the Birch-Murnaghan equation of state. The confirmation of structural stability in our materials is further supported by the absence of imaginary frequencies in the phonon dispersion calculations. The mechanical stability of both compounds is established by the relationship between their elastic constants, specifically C11 - C12 > 0, C11 > 0, C11 + 2 C12 > 0, and B > 0. However, it should be noted that these materials are characterized as mechanically anisotropic and ductile. By employing the highly promising Tb-MBj potential, the band gaps of Cs2YInCl6 and Cs2YTlCl6 have been calculated to be 4 eV and 0.9 eV, respectively. Cs2YInCl6 is categorized as an insulator, whereas Cs2YTlCl6 is considered a semiconductor. This distinction arises from the higher atomic mass of Tl in comparison to In, which results in elevated energy levels within the conduction band. A comprehensive investigation of the optical properties of both compounds was conducted within the energy range of 0 eV to 40 eV. It was found that these compounds exhibit significant absorption and optical conductivity in the higher energy range. Conversely, they demonstrate transparency to incident photons in the lower energy range. Based on our analysis of the optical properties, we have determined that these compounds are well-suited for applications in high-frequency UV devices. To the best of our knowledge, this study represents the first comprehensive theoretical analysis of the structural, elastic, electronic, and optical properties of Cs2YXCl6 (X = In and Tl), which have not yet been experimentally confirmed. In Summary, Cs2YXCl6 (X = In, Tl) exhibits significant promise for both solar cell and thermoelectric applications, showcasing its potential to contribute to the advancement of renewable energy and efficient energy conversion technologies.

Solution-based 3D printed thermoelectric composite for custom-shaped thermoelectric generator applications

To fulfill the ever-increasing power demands of deep space exploration, the output performance of radioisotope thermoelectric generators, the only accessible power source, must be enhanced in several aspects, including thermoelectric properties of materials, geometry, welding, etc. In this study, we present our results on the development of a novel thermoelectric slurry suitable for the 3D printing of thermoelectric generators with optimized leg geometry. The rheological properties of the slurry are optimized by combining proper amounts of organic solvent, binder, and bismuth telluride-based thermoelectric powder. The addition of Cu to the slurry as a conductive additive are also investigated. The homogeneous dispersion of Cu within the material not only increases the electrical conductivity of the final thermoelectric leg significantly but also promotes the crystallization of the thermoelectric particles during the sintering process. These effects result in 3D-printed thermoelectric composites exhibiting ZT values up to 0.91 and extended optimum operating temperature range. Thermoelectric modules composed of 3D-printed thermoelectric legs show excellent output performance and structural strength. This work could also produce other special shaped thermoelectric devices to match irregularly shaped heat sources to reduce contact heat loss and improve output performance.

Impact of terbium (Tb) on ferromagnetism and thermoelectric behaviour of spinels MgTb2(S/Se)4 for spintronic

The ferromagnetism due to rare earth elements-based spinel chalcogenides has become emerging aspirant for spintronic devices. Therefore, theoretically computed electronic properties of MgTb2(S/Se)4 spinels are analyzed to comprehend the structural, magnetic, and thermoelectric characteristics. Thermodynamic stability is elucidated using the computed enthalpy of formation (ΔH), phonons dispersion band structures. Using structural optimizations, difference in the energy states has revealed the ferromagnetic (FM) state stability. The computed band structures (BS) and density of states (DOS) both depict a half-metallic ferromagnetic state exhibiting a net spin polarization at the Fermi energy level. The underlying ferromagnetic state has been suggested due to carrier mediated indirect RKKY exchange mechanism. The thermoelectric properties are calculated to evaluate their potential for wasted-heat to useful-electricity conversion applications. The small thermal conductivity, and high-power factor exhibited by MgTb2S4 at room temperature suggest it significant for applications in thermoelectric generators.

Anomalous Nernst effect in honeycomb and kagome magnet LaCo5 at room temperature

Magnetic order-induced time reversal symmetry breaking in the kagome lattice is predicted to generate Weyl semimetal and Chern insulating phases. The two-dimensional (2D) honeycomb lattices with spin orbit coupling (SOC) and ferromagnetism are also known to host the Chern insulating phase. Here, we study the transport properties of the ferromagnetic topological material LaCo5 crystals with TC = 840 K, which is the highest among the reported magnetic topological materials up to now. It is composed of 2D Co2 kagome layers that are separated by La–Co1 layers, in which the Co1 atoms exhibit a honeycomb structure. Both the 2D kagome and honeycomb layers exhibit out-of-plane magnetization. The large intrinsic anomalous Hall effect and anomalous Nernst effect of about 4.6 μVK−1 are observed in the ab plane with the B//c configuration at room temperature, which can be attributed to non-zero Berry curvature according to the first-principles calculations. Our results enrich the magnetic topological materials with honeycomb and kagome lattices, providing a good platform for the further study of the QAHE. The excellent thermoelectric performance, high TC, nontoxicity, and low cost also make LaCo5 a promising candidate for the applications of thermoelectric generators and heat flow sensors at high temperatures.

Highly Stretchable, Resilient, Adhesive, and Self‐Healing Ionic Hydrogels for Thermoelectric Application

AbstractHarvesting low‐grade waste heat from the natural environment with thermoelectric materials is considered as a promising solution for the sustainable energy supply for wearable electronic devices. For practical applications, it is desirable to endow the thermoelectric materials with excellent mechanical and self‐healing properties, which remains a great challenge. Herein, the design and characterization of a series of high‐performance ionic hydrogels for soft thermoelectric generator applications are reported. Composed of a physically cross‐linked network of polyacrylic acid (PAA) and polyethylene glycol (PEO) doped with sodium chloride, the resulting PAA‐PEO‐NaCl ionic hydrogels demonstrates impressive mechanical strength (breaking stress >1.3 MPa), stretchability (>1100%), and toughness (up to 7.34 MJ m−3). Moreover, the reversible hydrogen bonding interaction and chain entanglement render the ionic hydrogels with excellent mechanical resilience, adhesion properties, and self‐healing properties. At ambient conditions, the electrochemical and thermoelectric performance of the ionic hydrogels can be restored immediately from physical damage such as cutting, and the mechanical healing can be completely restored within 24 h. At the optimized composition, the Seebeck coefficient of the ionic hydrogels can reach 3.26 mV K−1 with a low thermal conductivity of 0.321 W m−1 K−1. Considering the excellent mechanical properties and thermoelectric performance, it is believed that the ionic hydrogels are widely applicable in ionic thermoelectric capacitors to convert low‐grade heat into electricity for soft electronic devices.

Energy Harvesting on AB-Class Power Amplifier Applying Thermoelectric Generators in Push–Pull Mode

Amplifiers are among the most commonly used circuits in electronics, performing a variety of functions in a wide range of electronic systems. Depending on the application and design, each amplifier generates waste heat. For power amplifiers that operate at low efficiency and high output power, the amount of wasted energy can be significant. This paper presents an energy harvesting system based on the application of thermoelectric generators on the output transistors of the AB-Class power amplifier. The converted electrical energy can be used in several ways, feeding the energy back into the power supply (increasing the “efficiency”) or powering surrounding sensors and sub-circuits. In this work, a comparative analysis of the successfully converted energy obtained from different generator models in various thermal configurations was carried out. All measurements are performed on an experimentally established setup. Due to the low thermoelectric efficiency of the generators as well as the realized low temperature gradient, only 0.84% of the waste heat can be converted into electrical energy in the best case scenario. Finally, a new thermal push–pull concept was presented, the main purpose of which is to generate additional energy and protect semiconductor components from overheating.

Thermoelectric Generator Design and Characterization for Industrial Pipe Waste Heat Recovery

Thermoelectric technology is an effective strategy to convert low–grade waste heat to electrical energy directly. Thermoelectric generators (TEGs) have been extensively studied in various waste heat scenarios, such as vehicle exhaust, metal casting processes and more. However, industrial pipelines also possess high levels of heat and wide distribution, yet there is limited research on TEGs for use in these pipes. The challenge in designing a TEG lies in the heat collector, which is complicated by the distinct structural differences between pipe and plate–shaped TEMs. Ultimately, we propose an arch bridge–shaped heat collector for the pipe to recover wasted thermal energy. The effects of some key factors, such as topology of TEMs, heat source temperature, cooling water temperature and velocity, on the generating performance are studied. The TEG achieved a temperature difference of 65.98 °C across the two ends of the TEM, resulting in an output power of 17.89 W at an open–circuit voltage of 133.35 V. This provides evidence that the designed heat collector is a feasible solution for recovering waste heat from pipes using TEG technology. This work provides reliable experimental data and efficient design for the application of TEGs in industrial pipes.

Application of Np–Am Mixture in Production of 238Pu in a VVER-1000 Reactor and the Reactivity Effect Caused by Loss-of-Coolant Accident in the Central Np–Am Fuel Assembly

This paper presents the results obtained from numerical evaluations for the possibility of large-scale 238Pu production in the light-water VVER-1000 reactor and the reactivity effect caused by the loss-of-coolant accident in the central fuel assembly of the reactor core. This fuel assembly containing the Np–Am-component of minor actinides was placed in the center of the reactor core and intended for intense production of 238Pu. Optimal conditions were found for large-scale production of plutonium with an isotope composition suitable for application in radioisotope thermoelectric generators. The reactivity effect from the loss-of-coolant accident in the central Np–Am fuel assembly was evaluated, and the perturbation theory was used to determine the contributions of some neutron processes (leakage, absorption, and moderation) to the total variation of the effective neutron multiplication factor.

A Review on Thermoelectric Generators: Structural Optimization and Economic Analysis

The interest in recovering waste heat has resurged in recent years due to growing concerns about the energy crisis and global warming. A thermoelectric generator (TEG) is regarded as an environmentally-friendly technology for capturing and recovering waste heat by directly converting heat to electrical energy via the Seebeck effect. The critical challenge in improving this technology is the low conversion efficiency of the TEG device, thus limiting its application to a niche area. The structural optimization of TEG has been the subject of extensive research over the past few years. Nonetheless, there is currently a lack of review studies focusing on TEG structural optimization, and to the best of our knowledge, only one review paper associated with this key area is available in the literature. This work presents an analysis of the ongoing research progress of TEG structural optimization with a focus on the thermoelectric leg length, leg cross-sectional area, angle of the legs, and leg shape. In addition, the economic analysis of the application of TEG in recovering waste heat is also presented to rationalize the economic feasibility of this technology compared to other existing technologies.