Cold Side Research Articles

A low-power thermoelectric power generation system based on a periodic thermoelectric power generation method in the form of heat pulses

In today's increasingly serious energy problems, thermoelectric power generation is now widely used as one of the cleanest energy conversion methods. In this paper, we proposed a way of generating thermoelectric power periodically in the form of heat pulses and design an experimental system with low power consumption of fan blades. In contrast to conventional thermoelectric power generation with continuous contact with the heat source, this method maintains the temperature gradient between the hot and cold sides at a larger value for a longer period using periodic contact of the thermoelectric generator (TEG) with the surface of the heat source in the form of heat pulses. So it enhances the efficiency of thermoelectric power generation. The output power of the heat-pulsed thermoelectric power generation from a single TEG with heat sink is 19.81 mW with an efficiency of 6.05 %, which is an improvement of 23 % and 10.8 % over the conventional method. The whole system has an output power of 63.3 mW, an improvement of 293 %. This clean and efficient new type of TEG system can be widely used in the future in areas such as petrochemical waste heat treatment and self-supply of energy for Internet of Things (IoT) sensors.

Experimental Study and Performance Analysis of Thermoelectric Cooler Using Solar Photovoltaic Energy

Thermoelectric coolers need electrical energy to create temperature differences between the hot and cold sides; however, photovoltaic systems immediately convert solar radiation into electrical energy. The study is a combined (PV-TEC)—experimental study on a thermoelectric cooler operating by the Peltier effect to analyze and develop the TEC. One TEC was used, and its dimensions were (40*40*3.4) mm. The current required by the TEC is 6A and 12V DC. The thermoelectric cooler is electrically powered by a solar system consisting of two 660W solar panels, a solar charger and two 12V batteries. The results revealed a relationship between the coefficient of performance and the input energy, as the COP showed an increase as the input energy decreased, which is an essential factor for the cooling process. The temperature difference, which was the difference between ambient and cold temperatures, is related to the COP. The COP rises as the temperature difference decreases until it becomes stable. Moreover, the consumption current is an important factor in electronic devices, so the study focused on demonstrating the effect of the cold side temperature on the current, and an empirical equation was found between them. It has been found that a decrease in the temperature of the cold side leads to a sharp reduction in the consumption current until it stabilizes. The maximum coefficient of performance was 3.7436, obtained at the current 1.4 and cold side temperature of zero degrees centigrade. This high value of the coefficient of performance resulted from using curved fins to improve heat dissipation from the hot side.

Experimental analysis on the thermoelectric effect of various solid-state devices used for direct conversion of thermal energy into electrical energy

In this present investigation, the performance of thermoelectric generators (TEGs) was determined for the TEGs made of lead telluride (PbTe3), bismuth telluride (Bi2Te3), silicon germanium (SiGe), and aluminum oxide (Al2O3). In response to variations in the heat input rate and water flow rate, the electric power generated by the TEG was recorded and studied for the aforementioned TEG materials. During the investigation, the water flow rate to the TEG's cold side was chosen to be 0.5 lpm to 2 lpm in the step of 0.5 lpm, and the thermal energy input rate to the hot side was set at 30 W–120 W in the step of 30 W. Among all the TEGs Bi2Te3 was superior in terms of power generation potential in comparison to other TEGs in all the test conditions. The investigation also reveals that all TEGs appear to have a high-power generation when the cooling water flow rate was 2 lpm and the heat input rate was 120 W. At a water flow rate of 2 lpm for the case of Bi2Te3, the power generation potential was elevated by about 20.3 %, 14.4 %, and 6.5 % in comparison to Al2O3, PbTe3, and SiGe respectively.

Cold-hot Janus electrochemical aptamer-based sensor for calibration-free determination of biomolecules

Real-time, high-frequency measurements of pharmaceuticals, metabolites, exogenous antigens, and other biomolecules in biological samples can provide critical information for health management and clinical diagnosis. Electrochemical aptamer-based (EAB) sensor is a promising analytical technique capable of achieving these goals. However, the issues of insufficient sensitivity, frequent calibration and lack of adapted portable electrochemical device limit its practical application in immediate detection. In response we have fabricated an on-chip-integrated, cold-hot Janus EAB (J-EAB) sensor based on the thermoelectric coolers (TECs). Attributed to the Peltier effect, the enhanced/suppressed current response can be generated simultaneously on cold/hot sides of the J-EAB sensor. The ratio of the current responses on the cold and hot sides was used as the detection signal, enabling rapid on-site, calibration-free determination of small molecules (procaine) as well as macromolecules (SARS-CoV-2 spike protein) in single step, with detection limits of 1 μM and 10 nM, respectively. We have further demonstrated that the J-EAB sensor is effective in improving the ease and usability of the actual detection process, and is expected to provide a universal, low-cost, fast and easy potential analytical tool for other clinically important biomarkers, drugs or pharmaceutical small molecules.

High-Performance Printed Ag2Se/PI Flexible Thermoelectric Film for Powering Wearable Electronics.

We report the magnificent thermoelectric properties of the n-type Ag2Se film printed onto a flexible polyimide (PI) substrate. The orthorhombic β-Ag2Se phase of the processed Ag2Se film is confirmed from the X-ray diffractogram. Remarkably, the resulting Ag2Se/PI film exhibits outstanding thermoelectric properties, boasting maximum power factors of 1.4 and 2.1 mW/mK2 at 300 and 405 K, respectively. Furthermore, the flexibility of the Ag2Se/PI film remains intact even after undergoing 1500 bending cycles with no degradation observed in its thermoelectric performance. To demonstrate the practical application of our findings, a flexible thermoelectric prototype is constructed using the fabricated Ag2Se/PI films, which can harvest an impressive output voltage of 52 mV across a temperature difference of 53 K. Additionally, the prototype generates a maximum power output of 7.2 μW with a 40 K temperature difference and can produce 13 mV output voltage when subjected to around a 10 K temperature gradient when the cold side temperature is maintained at 308 K. Moreover, leveraging body heat with just a 1 K temperature variance between the body and the surrounding environment, the prototype could yield an impressive voltage output of 1.6 mV, marking the highest reported voltage output from human body heat to date. Our study not only introduces a cost-effective method for producing high-performance flexible thermoelectric films but also highlights their potential applications in wearable and implantable electronics.

Structural analysis and optimization of flattened tube gas cooler for transcritical CO2 heat pump systems

The performance of gas cooler is acknowledged as a vital factor in CO2 heat pump systems. Consequently, its optimal design can significantly impact the overall efficiency, attributed to the pronounced changes in thermophysical properties of CO2 during pseudo-critical operating conditions. This research examines, for the first time, various configurations of flattened tubes (FTs) utilized as the conduit for CO2 flow within the gas cooler. It is established that changing the cross-sectional configuration represents an effective approach for enhancing the thermal performance of the gas cooler, resulting in a significant increase of up to 60 % in heat transfer coefficient. All FTs exhibit superior overall performance across most CO2 cooling conditions compared to circular tubes. Regarding the performance index, the overall improvement can be reached up to 31.8 % and 18.6 % under near-critical and trans-critical conditions, respectively. Furthermore, an optimization is conducted using BBD-RSM for a specific alternating FT due to its potential to enhance the thermal performance not only on the CO2 side but also on the cold side of the gas cooler. The analysis highlights the significant positive influence of the minimum axis on the thermal and hydraulic specifications of gas cooler, followed by the transition length.

Influence of Operation Parameters on Thermohydraulic Performance of Supercritical CO2 in a Printed Circuit Heat Exchanger

The performance of recuperative printed circuit heat exchangers is critical in supercritical CO2 (sCO2) power generation applications. This article presents a three-dimensional numerical model of sCO2 flowing in a printed circuit heat exchanger and investigates its thermohydraulic performance under different operation conditions. The simulations employ the standard k-ε turbulent model, and consider entrance effects, conjugate heat transfer, real gas thermophysical properties and buoyancy effects. The heat exchanger operation parameters cover mass flux from 254.6 to 1273.2 kg/m2s, inlet temperature 50–150 °C and outlet pressure 100–250 bar on the cold side, and 300–500 °C and 75–150 bar on the hot side. Results show that increasing CO2 mass flux leads to a significantly increased heat transfer coefficient, a slight increase in temperature difference between the hot and cold CO2, as well as larger pressure drop and lower friction factor on both sides. Increasing the cold CO2 pressure, decreasing the cold CO2 temperature, and increasing the hot CO2 temperature result in a higher heat transfer rate of the heat exchanger. Increasing the CO2 temperature on each side causes increased pressure drops on both sides. Increasing the CO2 pressure on each side reduces the pressure drop on each side.

An efficient spider wasp optimizer-based tracker for enhancing the harvested power from thermoelectric generation sources

The distribution of heat at the cold and hot sides of a thermoelectric generator (TEG) is essential to its operation. Due to the inhomogeneous pattern, the TEG power-voltage (P–V) curve exhibits multiple peaks, which pose significant consequences for TEG generation. In order to increase the system conversion efficiency at this point, tracking global peak power (GPP) using a maximum power point tracker (MPPT) is crucial. The peak generation from TEG devices cannot be harvested by traditional algorithms such as hill climbing (HC) because they fall in local peaks. Therefore, the spider wasp optimizer (SWO), a new metaheristic-based tracker, is proposed in this paper to monitor the global power from TEG system operating at inhomogeneous heat distribution. In SWO, the iterative process of changing the population length aids in avoiding local solutions. The suggested SWO-based tracker is responsible for regulating the dc-dc boost converter linked to the TEG array terminals by giving its MOSFET the proper duty cycle. Seven inhomogeneous heat distributions are examined for two TEG arrays: symmetric 9 × 9 and asymmetric 10 × 15. These heat distributions are uneven row, uneven column, diagonal, outer, center, and random. The proposed approach is compared to artificial gorilla troops optimizer (GTO), gold rush optimizer (GRO), walrus optimization algorithm (WaOA), particle swarm optimizer (PSO), chef-based optimization approach (CBOA), cuckoo search (CS), Jellyfish search approach (JS), seagull optimization approach (SOA), and sine cosine approach (SCA). With regard to 9 × 9 array, the suggested SWO-tracker performed better than the published GTO method since it increased the generated power in the following scenarios: uneven row, uneven column, SN, diagonal, outer, center, and random patterns by 1.225 W, 0.4083 W, 19.5838 W, 2.4596 W, 1.394 W, and 2.4463 W, respectively. In asymmetric array, the suggested SWO performed better than all others, obtaining the least errors in relation to the Simulink GPPs of 0.016 W, 0.0822 W, 0.3615 W, 0.0603 W, 0.0569 W, 0.0081 W, and 0.0089 W. The obtained outcomes validated the proficiency and dependability of the suggested SWO-tracker in all examined cases.

Thermoelectric generator for energy production from renewable sources

Thermoelectric generators (TEG) produce electrical energy from a temperature difference between the cold and hot side of TEG modules (Seebeck effect); in principle, they can be used at temperature differences greater than 3 K [1]. Thermoelectric energy generation is primarily known for supplying self-sufficient sensors or in exhaust systems of motor vehicle internal combustion engines [2], where high temperature differences of up to 700 K are used. In this paper, basic investigations are carried out in order to expand the power range of thermoelectric energy generation and their potential for the energy transition. To this end, the area of application should be expanded to include medium and small temperature differences. The output characteristic of a TEG module has a power maximum, which increases quadratically with the temperature difference and linearly with the module area. At a temperature difference of 40 K, an output of 250 W/m2 can be generated. A solar module can generate 150 W/m2 in full sunlight; this output is only available for 12 % of the year given the 1000 full-load hours of sunshine that are usual in our latitudes. A continuous thermoelectric energy source could provide energy all year. Under optimal conditions, an annual usage time of 5000 hours and a service life of 10 years, electricity production costs of around 10 Cents/kWh can be expected [3]. This price is quite comparable to other renewable energy sources (photovoltaics, wind).

Pioneering hybrid heat recovery systems: Thermoelectric generators as insulators and channels boosted by vortex generators

Vortex generators are very effective tools in increasing heat transfer from one region to another, especially by convection, and appear to be a very promising concept to be coupled with heat recovery systems. On the other hand, Thermoelectric Generators (TEGs) are devices able to convert differences in temperature into electrical power using the Seebeck effect, the main advantage being working on high or even low differences in temperature. These TEG modules could be very effective tools in the hybridization of heat recovery systems. In this context, the present paper suggests an innovative system that couples three important energy axes together such as Heat recovery, TEGs, and Vortex generators. The current study employs a TEG in a rectangular channel to analyze the influence of the TEG on the flow and the effect of the effect of flow regime on producing electric power in order to assess the viability of this recently proposed concept. The investigation is conducted by varying the Reynolds number in a range of five values: 1000, 2000, 4000, 7000, and 10,000, applying six different configurations. Consequently, the results show that several factors affect the electrical power generated by TEG such as the emplacement, angle of attack, and absence/presence of vortex generators. On the other side, the heat recovered by the flow is affected by the TEG and Re, where the highest heat recovery is achieved at Re = 10,000 for configuration 4 with electrical power of 7.4 W, and for configuration 5 heat recovered by the flow of 1913 W. Besides, it was concluded that TEGs decreased the losses in both hot and cold sides by 1.42 times.

Amplifying the power density in thermoacoustic systems using a spring component.

This paper deals with the introduction of a spring component into a thermoacoustic system to increase the power density. This enables more compact and cheaper thermoacoustic systems. A theoretical and experimental study is presented to demonstrate the effect of the introduction of a spring component to amplify the thermal power in a thermoacoustic heat pump. The required spring constant is determined using an electrical circuit analogy model and a DeltaEC model of an existing heat pump. This is calculated for two locations in the system at the cold and hot side of the regenerator. The theory of the deflection of an elastic membrane loaded by a uniform pressure differential is used to calculate the required pretension of an elastic membrane used as spring to obtain the required spring constant. Elastic membranes are prepared and tested in the heat pump. The experimental results show that the insertion of the membrane at the hot side of the regenerator increases the power density by about 20%. The implementation of the membrane at the cold side of the regenerator increases the thermal power by about 100%. For both cases the improvement in the coefficient of performance is about 10%.

Experimental and computational investigation of passive heat exchangers to enhance the performance of a geothermal thermoelectric generator

Thermoelectric devices hold significant promise for generating electricity from geothermal heat, enabling the powering of measuring equipment in remote locations without the need for moving parts. Nevertheless, most developed geothermal thermoelectric generators employ fans and pumps to enhance heat transfer, thereby compromising the robustness and reliability inherent to thermoelectricity. Furthermore, there is a lack of research on passive heat exchangers for geothermal thermoelectric generators, particularly in studying their operation under a wide range of meteorological conditions. Therefore, this paper conducts a comprehensive analysis of passive heat exchangers for the cold side of the generators. Phase-change-based heat exchangers differing in their length and fluid are studied experimentally, along with a fin dissipator. Additionally, the influence of wind velocity on heat transfer and mechanical requirements is further explored through a Computational Fluid Dynamics model. The most significant outcome is quantifying the impact of the design parameters and operational variables on the electrical production of the thermoelectric generator. Accordingly, this research aims to broaden the application of these generators to extreme environments, such as Deception Island in Antarctica. Under average operational conditions, generators incorporating 400mm water heat pipes generate 0.95W per thermoelectric module, while those incorporating heat pipes with methanol achieve an average of 0.70W. Moreover, water and methanol-based systems produce 120% and 60% more power than generators using a fin dissipator. Nonetheless, for temperatures beyond -6.5°C, water might freeze and the methanol-based heat exchangers become more suitable.

IoT-driven monitoring and controlling to improve performance of thermoelectric air conditioning system

Thermoelectric module-based air conditioners (TEM-AC) are scalable, reliable, and have the potential to replace conventional air conditioners. However, the coefficient of performance (COP) of TEM-AC is still relatively low. Improving the COP requires a combination of temperature control, voltage control, heat recovery, airflow control, and material selection. The present study focuses on enhancing COP of the TEM-AC for building space cooling. To control and monitor the parameters of the TEM-AC, a low-cost, IoT-enabled monitoring and controlling system (MCS) is developed. The MCS helps in TEM-AC system designing as it can apply different current pulses to improve cooling capacity and control the temperature difference between both surfaces. MCS also measure all the required parameters of the TEM-AC to calculate the COP of the system and helps in reducing the calculation time for each experiment. Using a developed technique and TEM-AC design, a performance comparison of eight experimental cases has been done. Experiments have been performed in normal and control modes with different heat sinks and airflow of TEM-AC. The TEM-AC system is installed over a 16-inch × 12-inch enclosed space with a TEC-12706 module. The study indicates the COP of the system is enhanced by controlling the cold side temperature and air flow rate. For this study, maximum COP is achieved around 0.44 with control operation. The developed IoT-based monitoring and controlling system offers a promising solution for improving the performance of thermoelectric modules in building space conditioning applications.

Dynamic Simulation of a Molten Salt-Steam Superheater for Load-Following Applications

Abstract The growing use of intermittent renewables in electrical grids increasingly motivates load-following operations as a crucial capability of dispatchable power plants. However, frequent load variations in steam generation equipment can cause premature heat exchanger failure. This paper simulates the dynamic behavior of a high pressure, U-tube/U-shell, salt-to-steam superheater typically found in tower-type concentrating solar power subcritical Rankine cycles. Results focus on responses during load-following and inlet temperature changes. The proposed model is a finite volume method, and thermodynamic and heat transfer properties of both fluids are allowed to vary spatially and temporally. Several flow ramping schemes are investigated, including proportionally equal ramps and proportionally dissimilar ramping, where one fluid reaches its mass flow setpoint faster than the other. Results indicate that salt outlet temperature overshoot can occur if ramp rates are of sufficiently high magnitude, and that U-bend metal temperature rate of change can be approximately 2.5× that observed at either outlet. If proportionally-matched ramping is not possible, ramping steam more slowly than the salt is preferred over the alternative, as cold side and U-bend temperature responses are better regulated. Additionally, mass flow rate and inlet temperature changes are shown to elicit unique responses in the tube bundle metal.

Characterization of PCM-PCHE and its effect on the suppression of temperature fluctuations in the SCO2 Brayton cycle

Supercritical CO2 Brayton cycles are now widely used in industrial power generation systems based on various energy sources. In order to solve the temperature problem that is prone to occur at the outlet of the turbine, a printed circuit heat exchanger (PCHE) with phase change materials (PCM) incorporated in it is intended to minimize system temperature fluctuations at the cost of extremely low heat exchange loss.. In this paper, a numerical simulation method is used to study this PCM-embedded PCHE to investigate the overall heat exchanger performance. It is found that when the phase shift between the inlet fluctuations of the hot and cold sides is 180°, this PCHE with embedded PCM has the best reduction of the outlet temperature fluctuation amplitude. Then it was put into an overall supercritical CO2 Brayton cycle, and it was found that PCM-PCHE could reduce the amplitude of efficiency fluctuations by roughly 40.8 %, the overall stability of the system was significantly improved, average power generation was increased by about 1.6 kW based on the reduced power consumption of the two-stage compressor.

Manufacturing and measurement of CMOS-MEMS-based micro thermoelectric generators with long-length thermocouples

The study explores the fabrication and evaluation of a micro thermoelectric generator (MTG) with long-length thermocouples (TCs) through the utilization of a commercial complementary metal oxide semiconductor process. The MTG consists of 23 TCs, and its performance is intricately linked to the temperature difference (T diff) between the cold and hot sides of these TCs. An increase in T diff leads to higher output voltage and power for the MTG. To enhance T diff, the TCs are designed to be 700 µm in length, and an innovative design has been implemented on the cold side of the TCs, creating a suspended structure to improve heat dissipation A post-process is essential for achieving this suspended TC structure. The results demonstrate that the TC structure is fully suspended and remains undamaged. The measured outcomes reveal an output voltage of 13.8 mV when the T diff reaches 3.5 K. Under these conditions, the MTG exhibits a voltage factor of 2.76 mV mm−2K−1. Furthermore, at a T diff of 3.5 K, the maximum output power reaches 2.1 nW. The MTG demonstrates a power factor of 0.12 nW mm−2 K−2.

Waste heat management in electric motors using thermoelectric generator integrated with phase change material and metal foam-embedded heat sink

The waste heat management process from various thermal sources is associated with promising results in the energy conversion field. Thermoelectric generators integrated with phase change materials containing metal foams are useful means for recovering waste heat and converting it into electrical energy. Installing these hybrid cases on common heat sources and providing a practical strategy for waste heat management addresses a significant research gap in this field. The aim of this study is to manage waste heat from a three-phase asynchronous electric motor of a milling machine for the first time using a novel prototype thermoelectric system. Four thermoelectric modules (connected electrically in series) with zero-cooling energy phase change material and copper foam heat sink were embedded on the motor body. Hence, continuous and fluctuating loads were imposed on the motor, starting from ambient temperature. This caused the motor body to heat up and transfer the wasted heat to the module and the environment. The results of this study show that the proposed system was successfully started via the waste heat of the motor body. Thermal energy was absorbed from the hot side of the module, and the hybrid heat sink controlled the temperature of the cold side. Moreover, an appropriate temperature difference was provided across the module, and the system produced electricity for a long time during milling operation. The maximum output voltage in constant and periodic loads, with on/off durations of 180 s and 360 s, was recorded as 960 mV, 1280 mV, and 1440 mV, respectively. The mentioned hybrid thermoelectric system provides a unique solution for waste heat management in industrial applications, improving economic savings.

Computational fluid dynamics of flow boiling and conjugate heat transfer characteristics in a mini/micro-channel printed circuit steam generator

Numerical investigation of printed circuit heat exchanger PCHE was carried out for the water-steam system to optimize the design parameters for the possible use of PCHE as a steam generator in integral nuclear reactors- thus targeting efficient renewable energy by enhancing heat transfer. Heat fluxes, overall heat transfer coefficient (OHTC), and volume fraction of steam in a single channel of PCHE are reported for counter-current flow arrangement. The numerical model consisted of 1mm∗1.5mm single hot and cold channel. The heat transfer parameters were calculated using the Volume of Fluid (VOF) model in ANSYS Fluent with boundary conditions: top/bottom adiabatic; left/right periodic; mass flow inlet and pressure outlet. The effect of cold side degree of inlet subcooled (DISC) – varied from 100 to 0 K with a decrement of 20 K- and mass flux (200 to 500 kg/m2.s on OHTC, vapor fraction, pressure drop, and effectiveness was studied. For the fixed degree of subcooled, the OHTC and pressure drop increase as cold side mass flux increases. Similarly, for the fixed mass flux at varying DISC, the OHTC increases and pressure drop decreases for low mass fluxes up to 200 kg/m2.s because most of the channel remains in the nucleate boiling regime. However, with further increase in mass flux opposite trends in OHTC and pressure drop were observed due to single phased regime. The vapor fraction of steam increases with lower DISC at low mass fluxes and decreases with the increase in mass flux. The effectiveness decreases as the cold side inlet temperature approaches saturation temperature at 3 MPa.

Rancang Bangun Generator Termoelektrik Dengan Metode Efek Seebeck Sebagai Alternatif Pembangkit Energi Listrtik

One of the alternative technologies for generating electrical energy is a thermoelectric generator using the Seebeck effect method. This study aims to determine the effect of measuring angles and distances on the value of the Seebeck coefficient. This design consists of six peltier type TEC1-12706 in series and parallel, two digital multimeters to read voltage and current given a 10 ohm resistor, two DS18B20 sensors. waterproof to read the temperature from both sides of the thermoelectric with an aluminum plate on the hot side and a heatsink equipped with a 12 volt dc fan on the cold side, 20 x 4 character LCD, SD card module, RTC module and Arduino UNO R3 microcontroller. Tool temperature is made to get the comparison results obtained with an average error value with a range of 200C -100 0C of 1.330C sensor 1 and 1.150C sensor 2 and seen from the standard error value of the statistical test comparison of measuring instruments is 0.04 and 0.06. The design that has been made uses the Arduino IDE program to program and display data on the LCD and the RTC and SD card modules are used to display data in real time and store temperature data in the form of a notepad. Based on measurements of the thermoelectric output value with an angle of 600,900,1200,1500 and 1800 and distances of 5, 10, 15 and 20 cm using the heat source of the ironing elements positioned from the top, bottom and sides. The thermoelectric can produce a voltage of 0.22910 V and a current of 0.01238 A. The heater position from the side is connected in series and 0.05450 V, the current is 0.00261 A from the bottom in parallel which is obtained from the best angle of 600 at adistance of 5 cm.

Effects of temperature uniformity and nonuniformity on thermoelectric generator performance across hot and cold sides

Solar Thermoelectric Generators (STEG) are gaining attention for clean energy but face nonuniform temperature distribution due to optical concentrators and heat sinks. While prior studies used central circles or identical squares to represent temperature variations, this paper examines six circular and rectangular patterns. Using COMSOL, the TEG module was simulated under four boundary conditions: (1) uniform temperatures on both sides, (2) six patterns on the hot side, (3) six patterns on the cold side, and (4) six patterns on both sides for the first time. Experimentally, the I–V and P–V characteristics of STEG were measured using the capacitor technique for four concentration ratios (20, 40, 60, and 80 suns) obtained using the KIRAN-42 simulator. Simulations aligned well with all experiments under condition (1). The 3rd circular and rectangular pattern matched 11 times, while the 1st pattern matched once under conditions (2) − (4). The Root Mean Square Error (RMSE) between the measured and simulated Pmax, based on average measured temperatures, was 0.505. For condition (1), the RMSE was 0.017, while for conditions (2) − (4), it was 0.027 (0.033), 0.031 (0.031), and 0.044 (0.047) for the 3rd circular (rectangular) pattern, respectively. These findings indicate improved alignment between experiments and simulations.