Single Thermoelectric Generator Research Articles

Waste heat regeneration from thermoelectric generator based improved biomass cookstove (TIBC): Modelling of TEG system utilizing DC-DC converter with fuzzy logic MPPT

Most of the people in the rural areas cook their food in traditional biomass cookstove which emits a lot of emission that leads to poor health of the women and children. This paper points out a technology that utilises a thermoelectric generator (TEG), which converts thermal energy into electrical energy directly. A TEG is a small plate made of semiconductor p-n junctions connected electrically in series and thermally in parallel. The difference in temperature produced on the hot side and cold side of the TEG is proportional to the voltage generated. The TEG is integrated into the wall of the inner combustion chamber of the biomass cookstove with the help of heat plate and the cold side of the TEG is connected to a flower-type heat sink to maintain the temperature difference. The power generated by the TEG is used to drive a 12 V DC fan which helps to keep the cold side of the TEG relatively cooler and direct the same air inside the inner combustion chamber of the cook stove through holes to increase the air-to-fuel ratio. As a result, it improves the cookstove's combustion, thereby reducing emissions and increasing thermal efficiency. For testing the efficiency of the TEGs available in the market, a hit and trial method is used by taking TEGs of different specifications and connecting them to a hot side and a cold side test bed and then finally the performance is realized. Therefore, for every different TEG, a hardware has to be made for final conclusion of the result. To eliminate the hit and trial method, the electrical characteristics of thermoelectric generator module has been analysed by modeling a TEG module in MATLAB/Simulink and implementing it with fuzzy logic control (FLC) based MPPT utilizing a DC-DC boost converter with a constant as well as variable load. This fuzzy logic-based scheme exhibits fast dynamic response and precisely tracks the maximum power point (MPP) from TEG under varying load conditions. Based on the robust performance of the obtained simulation results, the TEG module is integrated and tested in the laboratory using a thermoelectric generator based improved biomass cookstove (TIBC). The novelty lies on the concept of using MATLAB/Simulink platform by modeling the FLC based MPPT incorporating boost converter to test the performance of TEG module for its integration with TIBC and eliminating traditional hit and trial method. This TIBC is able to power the fan directly within just 2–3 min using the electricity generated by the TEG module. The maximum power generated from the TIBC is 6.25 W using a single TEG. The fan requires 1.4 W and rest of the power was used to charge auxiliary battery.

Convection-effect-enhanced micro thermoelectric module directly heated by catalytic combustion

A novel micro thermoelectric power generation module directly heated with localized catalytic combustion has been proposed. Arrays of high-temperature plate-type thermoelectric generator (TEG) elements, of which the hot junction is directly heated by exothermic catalytic oxidation of hydrocarbon fuel, are designed. Heat losses caused by heat conduction through the TEG element are recovered by the convection effect with unburned mixture flows. Catalyst layers were prepared by impregnating Pd or Pt catalyst on porous Al2O3 supports coated by using the suspension plasma spray. A series of one-dimensional numerical analyses considering the catalytic combustion in addition to the conductive and convective heat transfer were made to examine the temperature field of the TEG module and to investigate how various parameters affect the convection effect. A model combustor using quartz plates was developed, which mimics the temperature fields of the SiGe TEG module. It is found that, with the aid of the convection effect, temperature differences over 700 °C between the hot/cold junctions can be achieved, while the unreacted fuel concentration is less than 10%. Finally, 40 mm-long Ni-based alloy TEG elements have been fabricated using laser cutting and spot welding techniques, which ensure high operating temperatures and reliability. In a power generation demonstration using butane as a fuel, an open circuit voltage of 0.64 V has been obtained from a single TEG module with a peak output power and a power generation density as high as 10.1 mW and 10.8 kW/m3, respectively.

A Constant Properties Model for the Performance Estimation in Segmented Thermoelectric Generator Elements and Its Experimental Validation Using an n-Type Mg2Si0.3Sn0.7–Bi2Te2.7Se0.3 Segmented Leg

Segmenting multiple compatible thermoelectric (TE) materials can improve the conversion efficiency in thermoelectric generators (TEGs) compared to single-material TEGs. A model to accurately estimate the performance in segmented TEGs is essential for optimizing the geometric parameters. Constant properties models (CPMs) help in the quick estimation of the performance of TEGs working under large temperature differences using averaged material properties. This work discusses a CPM to predict the performance of single and segmented TEG elements using a combination of temperature-averaged and spatially-averaged TE properties. Spatial averaging requires the knowledge of the temperature profile across the TEG element length, which was obtained by solving the heat balance equation with a numerical integration approach as suggested by Ponnusamy et al. In this work, we develop the CPM for the segmented TEG elements (CPMS). The model predictions were validated experimentally from the performance evaluation of single Mg2(Si0.3Sn0.7)0.98Bi0.02 and segmented Mg2(Si0.3Sn0.7)0.98Bi0.02–Bi2(Te2.7Se0.3)0.98(CuI)0.02 TEG elements. Single and segmented TEG elements with Cu contacts were prepared by a hot-pressing technique. Both Mg2(Si0.3Sn0.7)0.98Bi0.02 and Bi2(Te2.7Se0.3)0.98(CuI)0.02 TE materials show peak zT > 1 in their measurement range. The experimental results show a maximum efficiency (ηmax) of ∼8.25% with 18% improvement for the segmented structure at ΔT ≈ 302 K. The improvement mainly originated from lower heat input (Qin) even though the maximum power output (Pmax) became lower by ∼30%. The performance prediction using the CPM matches well with <10% error for Pmax and ηmax for the single TEG element, and using the CPMS, the predictions were <10% error for Pmax and <25% error for ηmax for the segmented TEG element experimental results. This work demonstrates how CPMS can be used to predict device performance characteristics in segmented TEGs.

Energy impact of heat pipe-assisted microencapsulated phase change material heat sink for photovoltaic and thermoelectric generator hybrid panel

As the importance of energy saving continues to increase owing to climate change, various Internet of Things sensors, related to building temperatures, humidity, and energy usage, are being employed in buildings, such as in building energy management systems. Aiming to satisfy the rapidly increasing electric energy demands of buildings, studies have combined various building-integrated photovoltaic (BIPV) and thermoelectric generators (TEGs) to recover sunlight and heat wasted from building envelopes. However, in most previous studies, active methods for heat rejection were applied to increase the temperature difference between both ends of the TEG and cooling of the solar panel. The actual constructability problems, such as leakage problems, were insufficiently addressed. Therefore, this study proposed a BIPV-TEG system with increased constructability and heat dissipation efficiency using a heat pipe and microencapsulated phase change material (mPCM). In addition, this study analyzed the thermal behaviors and improvements in power generation efficiency through field tests by manufacturing a prototype. The results of the outdoor experiment indicated that the BIPV-TEG-PCM prototype improved power generation efficiency by approximately 2% in the intermediate season and 2.5% in the summer relative to the efficiency of a general PV panel. Moreover, using a single TEG, approximately 3.06 Wh of the heat wasted in the building envelope can be recovered as a form of electricity annually.

High-efficient energy harvesting architecture for self-powered thermal-monitoring wireless sensor node based on a single thermoelectric generator

In recent years, research on transducers and system architectures for self-powered devices has gained attention for their direct impact on the Internet of Things in terms of cost, power consumption, and environmental impact. The concept of a wireless sensor node that uses a single thermoelectric generator as a power source and as a temperature gradient sensor in an efficient and controlled manner is investigated. The purpose of the device is to collect temperature gradient data in data centres to enable the application of thermal-aware server load management algorithms. By using a maximum power point tracking algorithm, the operating point of the thermoelectric generator is kept under control while using its power-temperature transfer function to measure the temperature gradient. In this way, a more accurate measurement of the temperature gradient is achieved while harvesting energy with maximum efficiency. The results show the operation of the system through its different phases as well as demonstrate its ability to efficiently harvest energy from a temperature gradient while measuring it. With this system architecture, temperature gradients can be measured with a maximum error of 0.14 ^{circ }C and an efficiency of over 92% for values above 13 ^{circ }C and a single transducer.

Design optimization of plate-fin heat sink with forced convection for single-module thermoelectric generator

Thermoelectric generators (TEGs) often use plate-fin heat sinks as cold side heat exchangers under forced convection. The available net electrical power obtained from these TEGs corresponds to that generated (Seebeck effect) minus that consumed (cooling fan). Generation and self-consumption have different trends as a function of the air flow speed, so a maximum of the net electrical power is expected when varying the cooling flow rate. Here, a semi-analytical model was developed to predict the maximum net electrical power of a single TEG module with a plate-fin heat sink with non-bypassed forced convection. The model was successfully validated with experimental data. It was applied to determine the heat sink design (fin thickness and fin-to-fin distance) that optimized the net electrical power for given values of hot source temperature, TEG properties, and duct cross-section. Numerical results indicated that the optimal dimensions of the plate-fin heat sink depended, among others, on the TEG effective properties. For a given TEG, the net output power was less sensitive to changes in fin thickness than in fin spacing. The optimal heat sink designs predicted by the model for the cases studied had fin thicknesses of 0.32 and 0.44 mm with fin-to-fin distances of 1 mm.

Experimental application of a laser‐based manufacturing process to develop a free customizable, scalable thermoelectric generator demonstrated on a hot shaft

AbstractGeometry, design, and processing in addition to the thermoelectric material properties have a significant influence on the economic efficiency and performance of thermoelectric generators (TEGs). While conventional BULK TEGs are elaborate to manufacture and allow only limited variations in geometry, printed TEGs are often restricted in their application and processing temperature due to the use of organic materials. In this work, a proof‐of‐concept for fabricating modular, customizable, and temperature‐stable TEGs is demonstrated by applying an alternative laser process. For this purpose, low temperature cofired ceramics substrates were coated over a large area, freely structured and cut without masks by a laser and sintered to a solid structure in a single optimized thermal post‐processing. A scalable design with complex geometry and large cooling surface for application on a hot shaft was realized to prove feasibility. Investigations on sintering characteristics up to a peak temperature of 1173 K, thermoelectric material properties and temperature distribution were carried out for a Ca3Co4O9/Ag‐based prototype and evaluated using profilometer, XRD, and IR measurements. For a combined post‐processing, an optimal sintering profile could be determined at 1073 K peak temperature with a 20 min holding time. Temperature gradients of up to 100 K could be achieved along a thermocouple. A single TEG module consisting of 12 thermocouples achieved a maximum power of 0.224 μW and open‐circuit voltage of 134.41 mV at an average hot‐side temperature of 413.6 K and temperature difference of 106.7 K. Three of these modules combined into a common TEG with a total of 36 thermocouples reached a maximum power of 0.58 K and open‐circuit voltage of 319.28 mV with a lesser average hot‐side temperature of 387.8 K and temperature difference of 83.4 K.

Experimental study of harvest solar energy based on thermoelectric generator with configuration variations

The background of this research is to optimize the use of heat from solar energy as energy harvesting based on a thermoelectric generator (TEG). One of the factors that affect the TEG output is the TEG configuration and the resulting temperature difference. The external temperature captured by the TEG side and the cooling system causes a significant temperature difference. This study uses a TEG trainer module consisting of eight TEGs and a double heatsink that functions for the cooling side and heat capture from the sun. Experiments show that the combination of eight TEG modules in series provides a maximum output significantly compared to single TEG and parallel modules at the same time with a temperature difference of 12.870C.

Fuel saving potential analysis of bifunctional vehicular waste heat recovery system using thermoelectric generator and organic Rankine cycle

Organic Rankine cycle (ORC) and thermoelectric generator (TEG) have both been identified as reliable waste heat recovery (WHR) technologies, although they are different in energy conversion efficiency, volume size and operating temperatures. The combined thermoelectric generator and organic Rankine cycle (TEG-ORC) system enables TEG and ORC to be complementary. In this study, a novel TEG-ORC system is proposed in a light-duty vehicle application. Regarding the space limitations in vehicles, the proposed system effectively uses existing components in the car to reduce the overall size. In addition, the TEG-ORC is a bifunctional system, which not only works for exhaust energy recovery, but also acts as a heating device for fast engine oil warm-up. The fuel saving potential of the TEG-ORC system is assessed against that of the baseline, standalone TEG and standalone ORC systems. The results show that TEG-ORC system effectively reduces the engine oil warm-up time and system hysteresis time of WHR. A significant increase of fuel saving potential is obtained when TEG and ORC are combined, which is not achievable by a single TEG or a single ORC. This seems a breakthrough for waste heat recovery in vehicle applications since the proposed TEG-ORC system is compact and has an acceptable fuel saving performance.

Enhanced Thermoelectric Power Generation Using Buck –Boost Converter

Energy generated in the vehicles depend on the engine and the fuel intake. But usually two thirds of the fuel added to the vehicle, which is, car, trucks bus etc. gets wasted as heat. The energy wasted as heat from areas like engine block, radiator, exhaust pipe engine coolant side and so on. So, to recover the waste heat as usable electrical energy back to the vehicle, Thermoelectric Generator (TEG) can be effectively utilized and its output power could be enhanced by connecting with buck boost converter. Here TEG with coupled inductor is used which produces smooth output with less ripples. TEG is placed in the engine exhaust of the vehicle and the output is connected with buck boost with coupled inductor converter so as to enhance the output voltage. Simulation using Comsol of single stage TEG without Buckboost converter produces an output of 6V.Interestingly TEG with Hotside temperature of 500K and coldside temperature of 300K with 127 legs is connected with buck boost converter with coupled inductor produces the output of 12 V and 0.65 mA is obtained to drive PIR sensor. Moreover in this paper Modified Maximum power point tracker (MPPT) algorithm is proposed to further improve the energy harvesting.

Thermoelectric Generators (TEGs) modules—Optimum electrical configurations and performance determination

&lt;abstract&gt; &lt;p&gt;Renewable energy technologies such as solar, thermal, wind, hydro, bio-fuels, fuel cells etc. are becoming trendy and being commissioned in large-scales, due to their environmental friendliness and energy sustainability. This manuscript focuses on alternative energy based-on thermoelectricity, particularly thermoelectric generators (TEGs). From the literature review, there is less emphasis on how multiple TEGs can be best configured electrically for optimum operations. In light of this, Matlab/Simulink were employed to institute a unique theoretical framework, that can easily be comprehensively used to simulate thermoelectricity parameters, with focus to determine TEG modules (of any quantity/configuration) optimal resistance matching and performance. The principal findings of the study are; 1) the effects of TEGs internal resistance, which proportionally causes output voltage drop and power loss as well as efficiency loss and 2) TEG modules may not be connected anyhow in series and or in parallel, but in a setup that gives a total electrical resistance that matches the load electrical resistance. Thus, TEGs should be a) of the same model with the same or approximate internal resistance, b) in a configuration whereby the TEGs total resistance equals the load resistance, as doing so ensures maximum power is transferred between the source (TEGs) and the electrical load and c) preferably be in a symmetrical electrical configuration. A symmetrical electrical configuration ensures ⅰ) the TEG modules total output resistance, irrespective of the quantity used, approximates that of a single TEG, with the overall TEG modules simply becoming now one large powerful TEG having an equivalent resistance of a single TEG and ⅱ) the TEGs power, voltage and current operations are optimal.&lt;/p&gt; &lt;/abstract&gt;

Effect of the density of TEGs on the efficiency of the generated electrical power in hot air flowing closed geometries: 3D numerical simulations approach

Computer simulations of three different geometries of thermoelectric generator (TEG) appliances have been carried out to calculate the maximum power generated by a single TEG and the maximum total power generated by all the TEGs in the geometries. Among these three geometries, every aspect was the same except the number of TEGs, so the density of the number of TEGs facing hot flowing air was varied. We used single-TEG, three-TEG, and five-TEG models. Simulations were carried out at 120 °C for the hot flowing air and at 42 different cold side temperatures to see the effect at different temperature differences. We showed the effect of the density of the TEG number on the maximum power generated. Powers generated by a single TEG from each geometry and the total generated powers in different geometries are compared. We have used the results we obtained to calculate the total electric energy generated by these TEGs in the wall of an industrial chimney for a six-month duration (between October 2017 and April 2018 in the winter season) by using real daily temperature data at a chosen site (the city of Kırıkkale) taken from the Turkey Meteorological Institute.

Power Generation using Thermoelectric Power Generator with Parabolic Solar Dish Concentrator

Solar Thermoelectric Generator (STEG), a hybridization system of thermoelectric generator (TEG) with a heat exchanger have been thoroughly explored because of its ability to produce both electricity and heat simultaneously. In this research, two tests were conducted: single TEG characterization test and STEG application. A theoretical modelling was developed based on the characterization test. For the STEG application, a solar parabolic dish concentrator and a single TEG were used to produce both heat and electricity simultaneously. An absorber plate placed on the focal point of the dish was used to facilitate the heat transfer of the reflected solar radiation to the TEG through the plate. The effects of various temperature difference were investigated. The absorber plate thickness was 1 mm and made up from copper to ensure high heat transfer rate and was well insulated so as to ensure minimal heat loss. To evaluate the performance of the TEG under the various temperatures, water-cooled cooling method (with water cooling jacket) and air-cooled cooling method (with finned heat sink and USB powered fan) were employed. Results showed that water-cooled cooling method was able to enhance the performance of STEG for higher power generation than air-cooled cooling method.

Enhancement of low grade waste heat recovery from a fuel cell using a thermoelectric generator module with swirl flows

This research analysed the enhancement to the power output of a thermoelectric generator (TEG) module in converting waste heat from a low temperature Polymer Electrolyte Membrane fuel cell into electricity assisted by swirl flows (swirl strength from 1.2 to 1.6). The module was constructed using a single TEG cell, a heat pipe and a finned heat sink. The study applied the scenario where the fuel cell operated as the power source for a mini fuel cell vehicle. This scenario provided a practical evaluation of the module performance as the hot stream temperature was varied due to the changes in fuel cell power while the cooling air varied according to the vehicle drive speed. The maximum power was enhanced from 200 μW (for non-swirl condition at 60 °C) to 3056 μW as the swirl strength increased to 1.6. Significant power enhancement factor by 8–17 in stationary mode and between a factor of 1.4–2.2 at the speed of 10 ms−1 were obtained with a non-linear relationship to the swirl strengths and cooling modes. Therefore, the introduction of swirl to the hot air stream is a viable approach to provide significant enhancements in low grade waste heat recovery using TEG.

Effects of leg geometry and multistaging of thermoelectric modules on the performance of a photovoltaic‐thermoelectric system using different photovoltaic cells

Research into improving the performance of photovoltaic (PV) systems using thermoelectric generators (TEGs) has gained increased interest in recent times. Few studies have separately investigated the effects of multistaging, thermoelectric geometry, and type of PV cell on overall performance of PV-thermoelectric (PV-TE) systems. Thermoelectric leg geometries considered in these studies were either rectangular or trapezoidal legs. The research work related to examine the combined consequences of PV cell type, TEG leg geometry and multistaging on the overall performance of PV-TEs has not been carried out till date. Therefore, a three-dimensional model of this hybrid system considering two different types of PV cells and the rectangular and circular TEG leg geometries in single and multistage arrangements has been investigated using ANSYS 2020 R2 software. A parametric study considering the effects of concentrated solar irradiation, TEG cold junction convective film coefficient and load resistance on the overall performance of the hybrid system has been carried out. Results show that, for both types of PV cell, the circular leg geometry of TEG provides the highest PV-TE performance. Also, the PV cell type significantly affects the optimum number of TEG stages in the PV-TE system. Finally, multistaging increases the thermal stresses developed in the PV-TE system, although the circular leg TEG provides the least thermal stresses as compared with the traditional rectangular leg TEG. Quantitatively, the PV-TE system with single and two-stage circular leg TEGs reduced the thermal stress levels of their rectangular leg counterparts by 3.31% and 0.78%, respectively. The findings of this study can be used as a reference for all types of PV cell in the PV-TE systems.

Effects of fuel cell vehicle waste heat temperatures and cruising speeds on the outputs of a thermoelectric generator energy recovery module

A thermoelectric generator (TEG) module is designed to harvest low grade waste heat from a 2 kW fuel cell vehicle and improve its energy utilization. The module integrates a TEG cell with a heat pipe and a finned heat sink. A numerical model is developed based on an experiment setup where the fuel cell temperature is 45–60 °C while the cruise speed is 25 kmh−1. The numerical model is validated with less than 5% deviation. Extended cases are simulated for series and parallel power train configuration under changes to the waste heat temperature and vehicle speeds to evaluate the power and heat recovery ratio. A single TEG cell output between 2 and 3 W is achievable even at low grade heat. The parallel drive generates 50% more power than the series drive at 100 kmh−1 speed. A 2% heat recovery is theoretically achievable for a 16 cell module assembly.

Modeling of enhanced micro-energy harvesting of thermal ambient fluctuations with metallic foams embedded in Phase Change Materials

We present an enhanced micro-energy harvester to transform ambient thermal fluctuations into electricity. The design consists of a Thermoelectric Generator (TEG) joined to a thermal storage unit improved with a Phase Change Material within a metallic foam (pPCM). We show how the augmented effective conductivity of the heat storage unit multiplies the production of electric power through voltage generation in higher and shorter sprouts. The porosity of the metallic foam accelerates the heat transfer and permits higher volumes of the heat storage unit to be effective in harvesting more energy from the surroundings. The pPCM/TEG device is a robust and cost-effective means to optimize the output of TEG based systems to power low-consumption electronics. The potential of this design is demonstrated with examples of micro-energy harvesting under ambient thermal conditions in an aircraft and ground solar irradiation. In these applications, a single TEG module with a moderate merit figure is used and found that pPCM allows a substantial optimization of energy conversion. As an example, the pPCM/TEG devices produce about twenty times more electric energy at even small volume fractions of the foam ε=0.95 than PCM/TEG systems in solar micro-energy harvesting on ground conditions with low thermal gradients.

Experimental Investigation of Passive Water Cooling in Solar Heating Thermoelectric Generator

In this study, a thermoelectric generator (TEG) system is designed to produce electricity from solar energy. Solar powered two-phase closed thermosiphon (TPCT) type heat pipe is used to heat the hot surface of the TEG, and a 1200 cc capacity passive water-cooled system is designed and manufactured to cool the cold side. The cooling system has two sections as primary and secondary sections which provide a natural water circulation to achieve an efficient cooling. A single TEG is used in most studies in the literature while 5 TEGs are used in this study to obtain a simple, easy and cheap design to generate more electricity. Not only the effect of passive water cooling, but also the effect of using a reflector on the system efficiency is tested experimentally. The system is operated by solar power under three different conditions as non-reflector, semi-reflector and full-reflector. Electrical and thermal data are recorded in a computer and data obtained from 08:00 to 15:00 is used for comparison and calculations. Maximum output power, electrical efficiency and Seebeck coefficient calculations are made for only TEG-1 in which the maximum open-circuit voltage is reached. Results showed that using a heat pipe with a small capacity passive water-cooling, the temperature difference for five TEGs can be reached to generate electricity.

Dynamic piezo-thermoelectric generator for simultaneously harvesting mechanical and thermal energies

In recent decades, the development of eco-friendly technology has attracted tremendous attention due to the energy crises and environmental issues in modern society, especially for the enhancement of energy efficiencies and the energy harvesting of secondary or waste energies. Conventional approaches in the energy recovery of industrial waste heat mainly focus on heat scavenging, whereas the kinetic energy is neglected. Nonetheless, mechanical/kinetic energy harvesting of the heating fluid has a critical effect on the power density improvement of waste energy utilization. Herein, a dynamic piezo-thermoelectric generator (dPTEG) prototype is designed and fabricated based upon the Brayton cycle system and demonstrated for the simultaneous harvesting of low-grade mechanical and thermal energies. In this dPTEG, radial PVDF-based piezoelectric generators (PEG) and annular Bi2Te3-based flexible thermoelectric generators (TEG) are used to simultaneously utilize the mechanical and thermal energies of working fluids. PEG and TEG energy converters are optimized from energy flow and thermal-electrical equivalent circuit model perspectives to illustrate the mechanical-thermal-electrical coupling of piezo-thermoelectric energy recovery. The length-specific power of the dPTEG with series and parallel connections of 55 μW/cm and 19 μW/cm, respectively, are achieved under steady-state flow (473 cm3/s and 4 K temperature difference). Moreover, the series and parallel electrical outputs are improved by 35% and 158%, respectively, compared with traditional single TEG energy conversion under similar working conditions. These results indicate that the dPTEG presented here offers a feasible solution to utilize the low-grade mechanical/thermal energy and industrial waste heat of heating fluids. Additionally, the long-time stability and reliability evaluation of the dPTEG further verifies the potential application of this system in day/night environments with multi-range temperatures and flow rates.

Simulation of Si/Ge based thermoelectric generator

A thermoelectric generator based on a SiGe superlattice was simulated using the COMSOL Multiphysics software platform. Based on the created model, a prototype generator sample can be made.The output power of a single thermoelectric generator was 0.048 μW with a temperature difference ΔT = 50 K. The generator area was 32 mm2, and the thickness was 1 mm.This makes it possible to combine 100 or 500 single generators into one on a flexible basis.This type of a TEG can be used as an energy source for different type of autonomous devices, for example, sensors or microdevices.