Thermoelectric Generator Research Articles

Two-dimensional BiSbTeX2 (X = S, Se, Te) and their Janus monolayers as efficient thermoelectric materials.

Today, there is a huge need for highly efficient and sustainable energy resources to tackle environmental degradation and energy crisis. We have analyzed the electronic, mechanical and thermoelectric (TE) characteristics of two-dimensional (2D) BiSbTeX2 (X = S, Se and Te) and Janus BiSbTeXY (X/Y = S, Se and Te) monolayers by implementing first principles simulations. These monolayers' dynamic stability and thermal stability have been demonstrated through phonon dispersion spectra and ab initio molecular dynamics (AIMD) simulations, respectively. The band structure of these monolayers can be tuned by applying uniaxial and biaxial strains. The investigated lattice thermal conductivity (κl) for these monolayers lies between 0.23 and 0.37 W m-1 K-1 at 300 K. For a more precise calculation of the scattering rate, we implemented electron-phonon coupling (EPC) and spin-orbit coupling effects to calculate the transport properties. For p(n)-type carriers, the power factor of these monolayers is predicted to be as high as 2.08 × 10-3 W m-1 K-2 and (0.47 × 10-3 W m-1 K-2) at 300 K. The higher thermoelectric figure of merit (ZT) of p-type carriers at 300 K is obtained because of their very low value of κl and high power factor. Our theoretical investigation predicts that these monolayers can be potential candidates for fabricating highly efficient thermoelectric power generators.

Probing the structural, mechanical, electro-magnetic, thermodynamic and thermoelectric properties of inner-transition based RaXO3 (X: Pr and U) cubic perovskites via first principle calculations

Here, we present ab-initio calculations of the structural, mechanical, electronic, magnetic, thermodynamic and thermoelectric properties of two radium-based perovskites by using density functional theory. These compounds are cubic in nature. Computation of tolerance factor, structural optimization by using the equation of state assures the stability of the materials. Further, we have checked the mechanical stability of the materials by computing the different mechanical parameters. The observed data of B/G and Cauchy pressure for the present materials reveals the ductile nature. The spin polarized band structures and density of states illustrate the half-metallic nature of these materials with the band gap of (3.74 and 4.80) eV in spin down channel for RaPrO3 and RaUO3 alloys respectively. The total magnetic moments calculated via GGA and mBJ approximations were found to be integral in nature (1 and 2) μB, for RaPrO3 and RaUO3 alloys respectively which also is an indication of the half-metallic character of these materials. The effect of temperature and pressure on the different thermodynamic properties like the specific heat capacity, thermal expansion and Gruneisen parameter were studied using the quasi-harmonic Debye model. Finally, we have speculated the temperature dependent thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, thermal conductivity and power factor. The summed -up properties suggest the applications of these materials in thermoelectrics, spintronics and thermoelectric generators outlooks.

High-performance waterproof flexible thermoelectric generators for self-powered electronics

Flexible and wearable thermoelectric generators (TEG) have emerged as promising energy sources for wearable health-monitoring devices. However, common thermoelectric generators are difficult to be applied to a wide range of application scenarios due to their poor durability, low output power, and susceptibility to human sweat or underwater environments. Here, we propose a waterproof wearable TEG with a gap structure. Through structural optimization and full-coverage elastomer encapsulation, the wearable TEG has a maximum power density of 4.38 mW∙cm−2 at a temperature difference (ΔT) of 30 K and exhibits good stability under aqueous environments, which is capable of supplying power to electronic devices even under submerged conditions. The internal resistance of wearable TEG changes by less than 10 % at 50 % stretch or 900 degrees of torsion, showing good flexibility and mechanical stability. Based on this, we designed an energy harvesting and management system to help wearable TEG collect and utilize energy on demand, and successfully implemented wireless transmission of human skin temperature data for underwater environments and real-time electrocardiograms (ECG) tests for health detection in air environments. This research provides a reliable method for powering wearable electronic devices using thermoelectric generators.

Effect of Heatsink Material on the Efficiency of Solar Panel-Thermoelectric Hybrid Devices

Solar panels exposed to solar radiation will produce heat, affecting their efficiency. A solution to this problem is integrating solar panels with thermoelectric generators that can convert thermal energy into electrical energy. In general, thermoelectric generators are equipped with heatsinks as heat absorbers. Many studies only look at the addition of heatsinks without examining the effect of the type of heatsink material used. Based on this background, this study identifies the effect of heatsink materials on the efficiency produced by solar panel thermoelectric devices. The purpose of this study is to determine which heatsink material can produce high efficiency in solar panel-thermoelectric devices. This research is useful for improving the efficiency of solar-thermoelectric hybrid devices. The novelty of this study is the selection of various heatsink materials that are directly tested against the efficiency of hybrid devices. The heatsink materials tested in this study were aluminum and copper. The equipment was tested by measuring the current and voltage generated by the solar panel-thermoelectric using a multimeter which was then used to calculate its power. The results showed that the hybrid solar panel-thermoelectric device with a heatsink made of copper produced a higher output power of 1.882 mW compared to aluminum material which was only 0.513 mW.

Ductile (Ag,Cu)2(S,Se,Te)-based auxetic metamaterials for sustainable thermoelectric power generation

Sustainable energy solution has resulted in significant interest in thermoelectric power generation, converting waste heat into electricity. However, the practical application of thermoelectric generators has been hindered by issues with their adaptability to arbitrary heat sources and durability in an operational environment. Here, we propose deformable auxetic thermoelectric metamaterials composed of high-entropy (Ag,Cu)2(S,Se,Te) ductile alloys, realized using finite element modelling and three-dimensional (3D) printing. We design a re-entrant auxetic structure with a negative Poisson’s ratio to maximize the mechanical deformability and develop an (Ag,Cu)2(S,Se,Te) particle-based colloidal 3D printable ink, tailored with Te microparticles. The 3D-printed (Ag,Cu)2(S,Se,Te) alloy exhibit a ZT value of 1.15 coupled with high compressive strength (208 MPa) and fracture strain (17.5 %). The fabricated auxetic metamaterials exhibit excellent vibrational stability and adaptability to diverse curved surfaces, realizing efficient power generation on a synclastic curved heat source. Our approach offers a method to design durable and efficient heat recovery devices.

Large Nernst effect in a layered metallic antiferromagnet EuAl2Si2

The large Nernst effect is advantageous for developing transverse Nernst thermoelectric generators or Ettingshausen coolers within a single component, avoiding the complexity of electron- and hole-modules in longitudinal Seebeck thermoelectric devices. We report a large Nernst signal reaching 130 μV/K at 8 K and 13 T in the layered metallic antiferromagnet EuAl2Si2. Notably, this large transverse Nernst thermopower is two orders of magnitude greater than its longitudinal counterpart. The Nernst coefficient peaks around 4 and 8 K at 3 and 13 T, respectively. At similar temperatures, both the Hall coefficient and the Seebeck signal change sign. Additionally, nearly compensated electron- and hole-like carriers with high mobility (∼ 4000 cm2/V s at 4 K) are revealed from the magnetoconductivity. These findings suggest that the large Nernst effect and vanishing Seebeck thermopower in EuAl2Si2 are due to the compensated electron- and hole-like bands, along with the high mobility of the Weyl band near the Fermi level. Our results underscore the importance of band compensation and topological fermiology in achieving large Nernst thermopower and exploring potential Nernst thermoelectric applications at low temperatures.

Tri-objective and multi-parameter geometric optimization of two-stage radioisotope thermoelectric generator based on NSGA-II

Radioisotope thermoelectric generator (RTG) is one of ideal power sources for deep space exploration due to the long service life and high stability. To further extend service life and improve electrical output, this study is first to simultaneously optimize electrical output and mechanical stability induced by thermal stress of the two-stage RTG using non-dominated sorting genetic algorithm-II. Skutterudite and bismuth telluride are used as the thermoelectric materials in hot-stage and cold-stage thermoelectric generators, respectively. The maximum von Mises stress of the skutterudite-stage (VonSKD) and bismuth telluride-stage (VonBT) thermoelectric generator and the conversion efficiency of the two-stage RTG (ηtwo) are set to the three objectives, and twelve geometrical parameters of two-stage RTG are used as variables. Electrical output and mechanical stability are simulated with COMSOL 6.0 Multiphysics software based on the finite element method. Results show that the ranges of ηtwo, VonSKD, and VonBT in the Pareto front are 4.81–7.57 %, 112.2–228.46 and 19.24–87.33 MPa, respectively, when the temperature difference is 300 K. TOPSIS decision-making method is used to select the specific optimal solution on the Pareto front according to the weight of the different objectives. Comparisons between tri- and bi-objective as well as single-stage optimization are also carried. Results show that there are strong influences among these three objectives. The performance of one objective would improve at the expense of the performance of the remaining objectives decrease if a larger weight was given. The VonSKD has the greatest importance among the three objectives, followed by ηtwo, and the smallest is VonBT. Skutterudite-stage thermoelectric generator should be particularly considered in the design of two-stage RTGs. The two-stage RTGs with different weight factors exhibit different electrical performances due to different geometrical parameters. This research can provide references for two-stage thermoelectric generators in more scenarios to improve electrical performances and extend service life.

The Graph Becomes the Dataset: Compiling Historical and Current RTG Data into One Place

Radioisotope thermoelectric generator (RTG) technology has a very long and incredibly successful history of providing heat and power to some of humankind’s most successful space exploration missions. Members of the community that support and maintain this technology often like to show the entire history of RTG performance on “The Graph.” Meant to impress, The Graph does its job in that regard. Unless you were connected to the right people, however, it was very difficult to get a copy of The Graph or its underlying data. This made it difficult for many to dive into the technical details or evaluate individual RTG performance from historical missions. To make matters worse, the performance for several missions in The Graph were incomplete. In 2020, with a little extra time on their hands thanks to COVID, the authors reached throughout the RTG community to locate and collate the missing RTG data. This information was then published as an open-source tabular Dataset. Users can now build their own version of The Graph or use the data for a more detailed analysis of RTG performance. Updates to the currently operating missions in The Dataset are expected to occur on a roughly annual basis. This Dataset represents the most comprehensive, authoritative, up-to-date repository of all RTG performance available today.

Boosting self-powered wearable thermoelectric generator with solar absorber and radiative cooler

The electrical output of wearable thermoelectric generators (wTEGs) has traditionally been constrained by small temperature differentials when powering microelectronics. In this study, we innovatively combine photothermal and radiative cooling mechanisms within a single wTEGs system, enabling substantial, uninterrupted power generation. Specifically, we designed a multilayer selective solar absorber (m-SSA) composed of flexible dielectric-metal stacks. This absorber demonstrates exceptional solar absorption efficiency of 93 % and significantly low thermal emissivity of 10 %. In practical outdoor conditions, it achieves a temperature increase of up to 108 °C under solar irradiation. Concurrently, we developed a flexible hierarchically porous radiative cooler (HP-RC), which reflects 96 % of solar energy and emits 97 % of thermal energy, achieving a cooling differential of up to 10 °C, even at ambient temperatures of 42 °C. Integration of the m-SSA and HP-RC with wTEGs allows for the simultaneous harvesting of heat from solar, cold space, and earth (robots or human body). This novel energy capture mechanism yielded a notable power density of 198 mW/m² for human body and 52 mW/m2 for steel robots in outdoor wearable applications. This significant advancement promotes the field toward high-performance, integrated green power technologies and holds promise for next-generation wearable self-powered devices.

Comparative Analysis and Integrated Methodology for the Electrical Design and Performance Evaluation of Thermoelectric Generators (TEGs) in Energy Harvesting Applications

Comparative Analysis and Integrated Methodology for the Electrical Design and Performance Evaluation of Thermoelectric Generators (TEGs) in Energy Harvesting Applications

Cost‐Effective Approach to Fabricate Oxide‐Based Bulk Thermoelectric Generator for Low‐Grade Waste Heat Harvesting

Oxide materials are well explored in thermoelectric and optoelectronic device applications due to their wide range of tunable properties, thermal stability, compatibility with other materials, nontoxicity, and earth abundancy. As a result, it can often be integrated into devices, which facilitates the development of oxide‐based thermoelectric generators at low cost. In this work, we synthesized BaxCoO2 and graphene‐doped In2O3 by solid‐state reaction route and then incorporated them in thermoelectric generator for the first time. A preliminary 3‐couple device is designed on a glass substrate. Here, the unique aspect is that graphite paint is used for the first time to make contact between oxide and metal electrodes instead of earlier used soldering and diffusion techniques, which prevents metals from diffusing in the oxide matrix. This device generates an open‐circuit voltage of 30 mV whereas it produces an output power of 0.3 μW with power density of ≈15.5 nW cm−2 for ΔT of 60 K, which is comparable to earlier reported metal‐based Bi0.5Se1.5Te3/Bi2Se0.3Te2.7TE devices. Further, the physical dimensions of the generators can be adjusted and the temperature gradient can be increased to get the desired power. This work offers a promising strategy for the development of thick as well as thin thermoelectric generators at an affordable cost.

Thermodynamic and economic analysis of a novel solid oxide fuel cell, two level thermoelectric generator and double effect parallel absorption chiller integrated system

This study presents a comprehensive thermodynamic and economic analysis of a novel hybrid energy system integrating a Solid Oxide Fuel Cell (SOFC) with a Two-Level Thermoelectric Generator (TTEG) and a Double-Effect Parallel Absorption Chiller (DEPAC) for enhanced waste heat recovery. The primary objective is to maximize energy utilization and overall efficiency by leveraging the synergetic effects of these components. Unlike previous studies, this research uniquely evaluates the effectiveness of the integrated system and examines the impact of different Absorption Chiller configurations and the number of TTEG elements, filling a critical gap in the literature. The proposed system achieves a net electrical efficiency of 42.88 %, an energy efficiency of 44.61 %, and an exergy efficiency of 57.16 % under optimal conditions. This marks a significant improvement compared to standalone SOFC systems, with the TTEG effectively harnessing waste heat and contributing an additional 0.680 kW/m2 to the overall power output. The integration of the DEPAC system further enhances performance by providing cooling with a Coefficient of Performance (COP) of 1.351. The economic analysis reveals a positive Net Present Value (NPV) of $1,993,136, a Dynamic Payback Period (DPP) of 6.7 years, and a Levelized Cost of Electricity (LCOE) of $59/MWh, underscoring the system's financial viability. These findings demonstrate that the hybrid system offers a sustainable and efficient solution for power generation and waste heat recovery, aligning with the broader goals of advancing renewable energy technologies and setting a new benchmark in hybrid energy system design and optimization.

Achieving High Thermoelectric Performance in Bi2(Te, Se)3 Thin Film with (00l)-Oriented by Incorporating Tellurization and Selenization Processes.

Flexible thermoelectric (TE) generators have received great attention as a sustainable and reliable option to convert heat from the human body and other ambient sources into electricity. This study provides a synthesis route that involves thermally induced diffusion to introduce Te and Se into Bi, fabricating an n-type Bi-Te-Se flexible thin film on a flexible substrate. This specific synthesis alters the crystal orientation (00l) of the thin film, improving in-plane electrical transportation and optimizing carrier concentration. Consequently, BixTeySe0.42 enhanced both the Seebeck coefficient and electrical conductivity, achieving a power factor of 17.1 μW cm-1 K-2 at room temperature. The TE device assembled with p-type Sb2Te3 exhibited exceptional flexibility with only a 26.2% change in resistance after 1000 times of bending at a radius of about 6 mm. The resistance change was further reduced to 7.5% after the application of a vinyl laurate coating. The fabricated TE device generated an ultrahigh output power of 792 nW with a temperature difference of 30 K.

Significantly Enhanced Thermoelectric Performance of p-Type Mg3Sb2 via Zn Substitution on Mg(2) Site: Optimization of Hole Concentration Through Ag Doping.

n-Type Mg3Sb2-based thermoelectric materials have recently garnered significant interest due to their superior thermoelectric efficiency. Yet, the advancement of p-type Mg3Sb2 for thermoelectric applications is impeded by its lower dimensionless figure of merit (zT). In this study, we demonstrate the improved thermoelectric performance of p-type Mg3Sb2 through the strategic optimization of Zn content and Ag doping on the Mg/Zn(2) site. Initially, samples of Mg3-xZnxSb2 (x = 0, 0.5, 1.0, and 1.5) were synthesized via elemental reactions within a Pyrex tube, followed by densification through hot pressing. X-ray diffraction analysis confirmed that the Mg3-xZnxSb2 phases retain the same Pm1 space group as the pristine Mg3Sb2 phase. The strategic substitution of Zn improved the power factor via band convergence and reduced lattice thermal conductivity by introducing point defect phonon scattering. This led to a peak zT of 0.5 at 725 K, with an average zT of 0.25 across the 325-725 K range. Enhancement in carrier concentration was achieved by doping Ag onto the Zn site, culminating in a peak zT of 0.95 at 725 K and an average zT of 0.46 between 325 and 725 K for the Mg2Zn0.97Ag0.03Sb2 sample. This performance surpasses that of most p-type Mg3Sb2-based materials, markedly advancing the potential for Mg3Sb2-based materials in midtemperature heat recovery thermoelectric generators.

Experimental evaluation and optimization of the heat pipes integrated thermoelectric generator using response surface methodology

In this study, integration of heat pipes with thermoelectric generators is proposed for the recovery of waste heat. Heat energy is transferred from a heat source to thermoelectric elements via heat pipes, enabling energy conversion. To dissipate excess heat from the system after conversion, additional heat pipes are positioned on the cold sides of thermoelectric elements. Cooling of the condenser sections of these heat pipes is facilitated using air flow provided by a fan. A novel approach in this study involves the innovative integration of heat pipes with thermoelectric generators. This integration provides a new pathway for optimizing waste heat recovery systems by combining advanced thermal management techniques with thermoelectric technology. Experiments conducted at different power inputs (12–42 W) and air velocities (0.4, 0.8, 1.2 m/s) determine the performance of the thermoelectric generator. Furthermore, a power usage efficiency analysis was conducted to discuss the applicability of the proposed method in electronics. At low air velocities, values below the ideal value of 1 were achieved. Experimental data were analyzed using response surface methodology to assess the impact of varying input parameters on the power output and efficiency of the thermoelectric generator. Optimization studies highlighted the importance of effectively cooling the cold side of thermoelectric elements. The highest power output and efficiency are achieved under conditions of 42 W power input, 1.2 m/s air velocity, and use of 4 heat sinks, yielding approximately 0.8 W and 2 %, respectively. Furthermore, the response surface methodology analysis indicated that the most significant effect on system outputs was the power input. Moreover, the results of this study lay the groundwork for future strategic advancements in thermoelectric generators, enhancing their role in sustainable energy solutions.

Enhancing the Performance of Photovoltaic Solar Cells using a Hybrid Cooling Technique of Thermoelectric Generator and Heat Sink

Abstract This study aims to enhance the performance of photovoltaic (PV) solar cells by employing a hybrid cooling technique involving a thermoelectric generator (TEG) and heat sink. Three configuration modules are investigated both experimentally and numerically: module 01: PV only (PV), module 02: PV with TEG (PV-TEG), and module 03: PV with TEG and heat sink (PV-TEG-HS). These modules have been examined numerically under various weather conditions, including solar radiation, wind speed, and ambient temperature. The experimental and numerical results indicate that as solar radiation increases from 500 to 1000 W/m2, the temperature of the PV back sheet and PV solar cell also increases. Specifically, for module PV, module PV-TEG, and module PV-TEG-HS, the temperature increases by 57.3%, 56.1%, and 32% respectively. Additionally, the percentage output power (Pout) of the PV increases with rising solar radiation for the three modules, reaching 60.5%, 62.0%, and 87.39% respectively. Moreover, the percentage Pout of the TEG also increases with the increasing solar radiation for the three modules, with percentages of 0%, 299.25%, and 311.96% respectively. Furthermore, increasing wind speed leads to a decrease in the temperatures of the back sheet and solar cell, while simultaneously increasing the Pout of the PV for all three modules. However, the Pout of the TEG in module PV-TEG-HS decreases. The impact of increasing ambient temperatures on module PV-TEG-HS is relatively small compared to the other modules.

Hybrid Energy Solutions for Sustainable Offshore Oil and Gas Operations: Leveraging Thermoelectric, Solar, and Wind Potential

The transition towards sustainable offshore oil and gas operations is increasingly important given the declining conventional energy reserves and growing environmental concerns. This research developed a concept design to enhance sustainability in offshore operations by integrating local solar and wind energy sources. The proposed hybrid system combines solar energy systems and wind turbines with traditional Thermoelectric Generators (TEGs), which have traditionally relied on natural gas. The study found that incorporating these renewable energy sources into the system significantly reduces carbon emissions, lowers dependency on fossil fuels, and improves overall operational efficiency. The main conclusion of this research is that integrating local renewable energy sources into offshore operations mitigates environmental impact, offers long-term cost savings, and enhances energy security. This framework provides practical solutions for the energy sector's transition towards greener, more resilient offshore operations.

Heat pipe-enhanced two-stage thermoelectric harvester based on phase change material

The thermoelectric generator (TEG) technology is important for improving energy efficiency. However, the TEG limited by poor thermoelectric material properties and thermal transfer strategies faces challenges in achieving excellent heat harvesting capacity, especially for large-temperature gradients. Herein, we reported a heat pipe-enhanced two-stage thermoelectric generator (HTTEG) enabled by bismuth alloy-based PCM for effective space waste thermal harvesting. We comprehensively explored the effects of different thermal-enhanced strategies on HTTEG performance. Compared with copper plate and horizontal layout, the effective thermal conductivity obtained by vertical-planar heat pipe is 1.1 × 104 W/mK enhanced by 79.2 and 33.0 times, which has outstanding advantages in achieving considerable temperature difference and excellent thermoelectric harvesting capacity of the HTTEG. We also systematically discussed the thermoelectric properties of heat pipe-enhanced one-stage TEG (HOTEG) and HTTEG by simulation and LED test bench. The results show that the bismuth alloy-based PCM with considerable latent thermal capacity and remarkable heat transfer characteristics can suppress temperature fluctuations and expand thermoelectric harvest interval, achieving excellent power output capacity. Compared with the HOTEG, the thermoelectric power achieved by HTTEG is 4.45 W enhanced by 581.8 %, because optimizing the spatial layout of stage-two thermoelectric modules to the high-temperature gradient interval achieves remarkable heat harvesting efficiency.

NiMoO4/Reduced Graphene Oxide Nanocomposites for Thermoelectric Power Generation

NiMoO₄/Reduced Graphene Oxide Nanocomposites for Thermoelectric Power Generation

A geothermal-based freshwater/cooling system assisted by heat recovery sections: 3E analysis and techno-economic optimization using genetic algorithm

The proposed system uses a dual-loop organic Rankine cycle, a reverse osmosis desalination unit, an absorption cooling unit, and a thermoelectric generator to produce electricity and freshwater for urban areas. A thorough assessment of the system's thermodynamic and economic performance has been conducted, with a parameter-based investigation to assess the effect of key variables on the system performance. The parametric study indicates that rising the geothermal mass flow rate enhances the energy efficiency, but lowers the energy efficiency and affects the cooling requirements. Moreover, the optimum inlet temperature in turbine 1 increases the desalination efficiency up to 105.02 kg/s at 115 °C, and higher temperatures reduce the performance and system efficiency. Adjusting the temperature difference at the pinch point at Evaporator1 is crucial for system efficiency, with trade-offs between freshwater output, expenses, and exergy efficiency. The capability of the system to produce up to 6,048,000 L of potable water daily signifies a monumental leap towards meeting the water demands of nearly 42,000 individuals, based on European consumption standards. Lastly, the application of genetic algorithms in the optimization process results in an exergetic efficiency of 32.79 % and a cost rate of 58.05 $/h, demonstrating the system's enhanced operational effectiveness.