Enhancement Of Output Power Research Articles

High performance deep violet InGaN TQW laser diode through multi-layer thickness optimization using particle swarm optimization method

The paper details the optimization of efficiency parameters for a InGaN TQW laser diode using the particle swarm optimization algorithm through SILVACO software. By adjusting layer thickness based on output power, slope efficiency, and threshold current, significant enhancements were achieved. Three optimized laser diodes (LD1, LD2, LD3) were compared with a primary LD, revealing notable improvements in output power and overall performance. Analysis of carrier recombination rates in the active region highlighted increased stimulated recombination and decreased non-radiative recombination, particularly in the n-side well. The study also showed a more uniform radiative recombination in the quantum wells of the optimized LDs, especially in LD3. Investigation of electron and hole concentrations, current densities, and energy levels demonstrated higher electron and hole current density in the optimized LDs, with LD3 exhibiting substantial improvements over the primary LD. Notably, the optimized LDs displayed reduced threshold current and improved slope efficiency compared to the primary LD. The study identified optimal layer thicknesses based on various cost functions, resulting in significant enhancements in output power (0.561 W), slope efficiency (2.515 W/A), and reduced threshold current (less than 0.029 A), indicative of enhanced TQW laser diode performance. Overall, the research showcases the effectiveness of the particle swarm optimization approach in optimizing GaN-based TQW laser diodes, leading to improved efficiency characteristics and demonstrating the potential for enhanced performance in practical applications.

Innovative materials integrated with PCM for enhancing photovoltaic panel efficiency: An experimental investigation

The electrical power generated by a photovoltaic panel is crucial due to the high demand for electricity. Operating temperatures above the Standard Test Conditions (STC) negatively impact the output power, which is a significant drawback of this technology. Therefore, it is essential to keep the front and back surface temperatures of the photovoltaic panel as low as possible. Phase Change Material (PCM) is a good passive cooling method, but it has low thermal conductivity. This paper introduces a novel material to address this issue. Iron Filling Waste (IFW) is integrated with PCM to cool the photovoltaic panel. This investigation is presented experimentally with three modules. The highest surface temperature of the reference panel, 78 °C, is recorded for the uncooled module, while with PCM- IFW is 70.5 °C. The comparative analysis shows that the PV module cooled by PCM-IFW achieved an efficiency enhancement and power output increase of 39 % and 33 % respectively, compared to the reference panel without cooling. IFW-PCM achieves an average enhancement in efficiency and output power by 23 % and 11 %, respectively, compared with panels that use PCM only. Also, IFW enhances thermal conductivity without any additional economic cost for the cooling systems.

Structure Design of UVA VCSEL for High Wall Plug Efficiency and Low Threshold Current

Vertical-cavity surface emitting lasers in UVA band (UVA VCSELs) operating at a central wavelength of 395 nm are designed by employing PICS3D(2021) software. The simulation results indicate that the thickness of the InGaN quantum well and GaN barrier layers affect the emission efficiency of UVA VCSELs greatly, suggesting an optimal thicknesses of 2.2 nm for the well layer and 2.7 nm for the barrier layer. Additionally, an overall consideration of threshold current, series resistance, photoelectric conversion efficiency, and optical output power results in the optimized thickness of the ITO current spreading layer, ~20 nm. Furthermore, by employing a five-pair Al0.15Ga0.85N/GaN multi-quantum barrier electron blocking layer (EBL) instead of a single Al0.2Ga0.8N EBL, the device shows a ~51% enhancement in the optical output power and a ~48% reduction in the threshold current. The number of distributed Bragg reflector (DBR) pairs also plays crucial roles in the device’s photoelectric performance. The device designed in this study demonstrates a minimum lasing threshold of 1.16 mA and achieves a maximum wall plug efficiency of approximately 5%, outperforming other similar studies.

Boosting Thermogalvanic Cell Performance through Synergistic Redox and Thermogalvanic Corrosion.

Thermogalvanic cells with organic redox couple (OTGCs) have received significant attention for low-grade heat harvesting due to their high thermopower, versatile molecular design, and tailorable physiochemical properties. However, their thermogalvanic conversion power output is largely hindered by slow kinetic rate, which limits practical applications. In this work, we demonstrate a high-performance liquid quinone/hydroquinone (Q/HQ) based OTGC by synergistic coupling redox reaction and thermogalvanic corrosion. By adding hydrochloric acid (HCl) into electrolyte solution, HCl not only boosts intrinsic redox kinetic rate of Q/HQ, but also induces rapid thermogalvanic corrosion of the copper electrode. Notably, these two processes reinforce each other kinetically. Consequently, the Q/HQ-based OTGC exhibits a rapid kinetic rate alongside an increased thermopower, leading to a significantly enhanced power output density. As a result, the Q/HQ-based OTGC achieves an enhanced effective electrical conductivity σeff of 4.22 S m-1 and a record high normalized power density Pmax (ΔT)-2 of 108.7 μW m-2 K-2. This strategy provides a feasible and effective method for development of high-performance OTGCs.

The effect of cycling shoe sole stiffness on sprint power output

Competitive and recreational cyclists use stiff-soled shoes that firmly attach to ‘clipless’ pedals. When compared to very flexible running shoes, very stiff cycling shoes with clipless pedals enhance power output during sprint cycling. However, a recent study showed no difference in power output or sprint performance between commercially available cycling shoes that span a range of longitudinal bending stiffnesses (∼200 to 500 N·m/rad). Thus, we sought to identify the likely range of sole stiffnesses below 200 N·m/rad over which reduced cycling shoe sole stiffness begins to decrease maximal power output. We measured the mechanical power outputs of 25 road cyclists during maximal sprints wearing shoes with identical uppers but with three different sole stiffnesses. Each participant completed nine 50 m sprints (three trials for each shoe) on a road with a steady, uphill grade of 9.1%. The three shoe sole conditions were: injected nylon (longitudinal bending stiffness 194 N·m/rad), moderate stiffness thermoplastic polyurethane (medium TPU) (43 N·m/rad), and low stiffness TPU (soft TPU) (9 N·m/rad) all ridden with the same clipless pedals. Stiffness was quantified using a simple testing apparatus. Power output decreased below the sole stiffness of ∼200 N·m/rad but only moderately. Maximal 1 s crank power (Pmax1) decreased −3.1% (ES = −0.59, p = 0.020) from Nylon to medium TPU and then further decreased −2.4% (ES 16 = −0.50, p = 0.054) from medium TPU to soft TPU. Interpolating our results suggests just a ∼1% loss in Pmax1 at a sole stiffness of 100 N·m/rad. Within reasonable limits, cycling shoe sole stiffness has only a small effect on power output.

Experimental Optimization of the SG6043 Airfoil for Horizontal Axis Wind Turbines Using Schmitz Equations

This study presents the experimental optimization of the SG6043 airfoil for horizontal axis wind turbines (HAWTs) using the Schmitz equation, focusing on enhancing power output and elucidating the surface flow structure. Two blade models, M1 (conventional) and M2 (optimized), were designed and tested at rotational speeds of 400 rpm and 600 rpm across a range of tip speed ratios (TSR). The M2 model, optimized using Schmitz equations, demonstrated significantly improved performance compared to the M1 model at both rotational speeds. At 400 rpm, the maximum power coefficient (CP) for M1 was 0.274, while M2 reached 0.419, indicating a 52.91% improvement. At 600 rpm, M1 achieved a maximum CP of 0.293, whereas M2 attained 0.458, representing a 56.31% enhancement. The M2 model also showed superior performance at higher TSRs, with the highest percentage increase in CP recorded at 4.9 TSR, reaching 574.54%. Additionally, dynamic surface oil-flow visualization experiments were conducted to examine flow behavior on the blade surfaces. Results indicated better flow attachment in the M2 blade due to its optimized twist angle and chord length, particularly in the mid-section, leading to delayed flow separation. The reattachment observed on the suction side of the M2 model, following the laminar separation bubble (LSB), which was absent in the M1, contributed to its higher aerodynamic efficiency and overall power performance. These findings confirm that the optimized SG6043 airfoil design, guided by Schmitz equations, offers significant improvements in HAWT performance, particularly under varying operational conditions.

Fabrication and evaluation of a CMOS-based energy harvesting chip integrating photovoltaic and thermoelectric energy harvesters

This study explores the development of an energy harvesting chip (EHC) using a complementary metal oxide semiconductor (CMOS) process, addressing the need for efficient micro-scale energy harvesters in modern electronics. The EHC integrates a thermoelectric energy harvester (TEH) and a photovoltaic energy harvester (PEH) to maximize energy conversion efficiency. A key challenge in TEH design is enhancing power output, which is addressed by suspending the cold ends of 41 thermocouples within the TEH structure through post-processing. Experimental methods were employed to assess the performance of the TEH, revealing an output voltage of 21.4 mV and a maximum output power of 9.32 nW under a 3 K temperature difference. The TEH demonstrated a voltage factor of 8.9 mV/(mm2·K) and a power factor of 1.3 nW/(mm2·K2). The PEH was designed with novel patterned p-n junctions, integrating lightly doped n-type regions with interdigitated p-type doping to increase junction density, resulting in high conversion efficiency. The experimental results confirm the effectiveness of the EHC design, showcasing its potential in energy harvesting applications.

Numerical Comparative Investigating of PEMFC with Novel Hybrid Zigzag Channels: Reaction, Transport and Drainage Enhancements

The impact of flow channel design on mass transport and drainage in proton exchange membrane fuel cells (PEMFCs) is significant, thereby influencing the reaction rate. Based on conventional wavy design, this study introduces two novel hybrid zigzag flow channels (asynchronous and synchronous) with both zigzag sidewalls and bottom wall, aiming in further improving mass and heat transfer, as well as drainage capacity to achieve better fuel cell performance. Numerical simulations demonstrate that the net power densities of both asynchronous and synchronous hybrid zigzag channels show a 28.7% and 44.4% improvement at low voltage, respectively. The implementation of the asynchronous hybrid zigzag flow channel has been observed to result in a notable reduction in pressure drop, amounting to 9.2%, while concurrently enhancing power output by 10.7% in comparison to a conventional zigzag channel. Additionally, the novel hybrid zigzag designs improve mass transfer efficiency at high current density and exhibits better temperature distribution uniformity. Moreover, the volume of fluid simulations illustrate that hybrid zigzag channels are highly effective in removing accumulated water, surpassing the straight channel with a drainage rate exceeding 54%, as well as a lower surface liquid coverage.

An open-loop and closed loop based passive thermal management techniques applicable to photovoltaic systems

Photovoltaic (PV) technology adoption in recent years has experienced significant growth due to its inherent advantages over alternative technologies. Nevertheless, there is a concern regarding performance deterioration due to high operating temperatures. Various thermal management methods have been studied to address this issue, each having its own advantages and disadvantages. Hence, a comprehensive review aimed at developing effective passive cooling techniques was undertaken and two techniques were finalized for outdoor testing viz. natural circulation loop based cooling (PV-NCL) and evaporative cooling (PV-EVP). Though the former version could drop module temperature by 7.4 °C–13.9 °C (Power output increment in the range of 3.5 %–6.7 %), this improvement was not sustained throughout the day due to factors such as flow resistance within the loop and a lack of convective cooling in the vicinity of the cooler. Subsequent experiments confirmed that loop resistance played a dominant role in this phenomenon. Additionally, concerns about water circulation in PV-NCL were resolved through a comparison with water duct-integrated PV. On the other hand, the innovative gravity-assisted water flow for evaporation method (PV-EVP) yielded more promising results, with a power output enhancement ranging from 3.7 % to 11.5 %. However, considering the in-field operational issues, PV-NCL with a modified design will likely be the best technique.

A direction-adaptive ultra-low frequency energy harvester with an aligning turntable

Ultra-low frequency vibrations in the ambient environment contain abundant sustainable energy. However, their time-varying and random direction nature poses a prominent challenge for the design of effective energy harvesters. This paper proposes a direction-adaptive ultra-low frequency energy harvester with an aligning turntable to ensure a systematic alignment between the pendulum swinging plane and the excitation direction. The aligning turntable is easily rotated by overcoming friction, thus reducing the deviation angle till zero. Experimental results verify the output power enhancement from several milliwatts to over 1 W owing to the alignment process. Moreover, setting resonance frequency with large amplitude vibration can significantly shorten the alignment time. Decreasing the pendulum swinging natural frequency contributes to a slower alignment process but enhances the system stability.

Self-decoupled coupler based dual-coupled LCC-LCC rotating wireless power transfer system with enhanced output power

Self-decoupled coupler based dual-coupled LCC-LCC rotating wireless power transfer system with enhanced output power

A genetic algorithm approach for flexible power point tracking in partial shading conditions

A novel Flexible Power Point Tracking (FPPT) algorithm based on Genetic Algorithms (GAs) is presented in this study. The algorithm is designed to effectively handle fluctuating solar irradiation levels and partial shading scenarios. The main objective is to enhance power output and tracking accuracy under dynamic environmental conditions, based on extensive simulations. The results showed superior performance for power output, tracking accuracy, and convergence speed than traditional techniques. Its adaptability to changing environmental conditions renders it suitable for real-time implementation, thereby contributing to efficient power generation in PV systems. Simulations demonstrate the efficacy of the algorithm in maximizing power extraction and meeting grid-code requirements under dynamic conditions. The comparative analyses underscore the superiority of the GA-based FPPT algorithm, highlighting its potential to significantly improve power point tracking in photovoltaic systems. This shows significance of adaptive algorithms in modern PV systems, particularly for reducing the effects of partial shading on energy yield. More research is required on the refinement of the algorithm's performance for long-term reliability and scalability in larger PV installations fostering advancements in photovoltaic power point tracking toward sustainable energy systems.

Numerical investigation of the effect of winglet configurations with multiple cant angles on the aerodynamic performance of wind turbine blade

ABSTRACT A numerical investigation of the effects of winglets with multiple cant angles on the power output of the blade of a horizontal axis wind turbine (HAWT) is conducted. Several winglet configurations with single and multiple cant angles are designed and their performance is evaluated. Numerical solutions obtained by RANS equations and moving reference frame method were compared with the experiments and demonstrated that they concur well with the experimental data. In the torque and thrust comparison, the ones with multiple cant angles present better power output enhancement than those with a single cant angle at a relatively high wind speed. The configurations of multiple cant angles are effective in reducing the influence of wing tip vortices, resulting in a higher torque while maintaining the same winglet length and height.

Development of Steg with Concentrating System

Solar cells, also known as photovoltaic cells, convert light energy into electrical energy through the photovoltaic effect. Integrating a thermoelectric generator into a photovoltaic system enhances power output and efficiency by utilizing waste heat. Concentrators are employed to further improve solar panel efficiency. This study aims to develop a solar thermoelectric generator (STEG) with a concentrating system that includes a heat sink cooling system, thermoelectric generator, and concentrator. Three conditions will be tested to observe the power output of each solar module: PV standalone, STEG with a heat sink, and STEG with a heat sink and concentrator. The efficiency appears to improve from 9.21% for PV standalone to 10.11% for STEG with a heat sink and 10.23% for STEG with a concentrating system. The results of these studies aim to establish a benchmark for enhancing the efficiency of future STEG systems.

Osmotic energy harvesting using acrylic acid hydrogel PET membrane

In this study, we investigated the osmotic energy harvesting using a cation-selective membrane. The cation-selective membrane was synthesized by the incorporation of acrylic acid hydrogel in a porous support membrane. FTIR analysis and SEM images confirmed the presence of the acrylic acid hydrogel rods inside the porous support material. The exposure of the acrylic acid hydrogel PET (AP) membrane to a concentration gradient culminated in the generation of electric power. The AP membrane was evaluated in regard to the following parameters: EDiff, Io, Pmax and t+. The maximum power obtained with the membrane was 1.10 μW at the 40-fold concentration gradient (test area∽ 100 mm2). Increasing the concentration gradient increased the power output. However, a decrease in power output was observed after a certain value of the concentration gradient. An enhancement in power output was noted as the fraction of acrylic acid within the membrane was augmented. Additionally, the cation transference number also increased owing to a high charge density and a reduction in the mesh size. The AP membrane was also investigated in acidic and basic media. The time-dependent study revealed the superior chemical stability of the AP membrane.

Enhanced and tunable near-field thermophotovoltaics driven by hybrid polaritons

Near-field thermophotovoltaics (NF-TPV) offers the potential for achieving elevated power density and conversion efficiency by leveraging the amplification of thermal radiation within a nanoscale gap. Here, we propose an NF-TPV device with a sandwich emitter composed of calcite film and graphene layer. The results show that this sandwich configuration can significantly enhance output power, outperforming monolayer-graphene-covered heterostructures and the single calcite film. These are because the sandwich configuration can enhance hybrid polaritons, which are formed by the coupling between surface plasmon polaritons in graphene and hyperbolic phonon polaritons in calcite. In addition, the effects of graphene chemical potentials on the performance of NF-TPV devices are also studied. The tunable power density range of the sandwich structure can be up to 3.26 times that of other structures by altering the chemical potential of graphene. The findings presented here may unpack a promising path for enhancing and manipulating the performance of NF-TPV at the nano- and microscale.

A novel one-time unified configuration strategy with L-SHADE optimizer for enhanced power extraction in thermoelectric generator array

The thermoelectric generator (TEG) is a promising green energy source, converting wasted heat into electric power without relying on chemical reactions or emitting harmful substances. However, a significant challenge obstructing its practical deployment is the power losses due to nonuniform temperature distribution (NUTD) within its modules, particularly in applications like solar-TEGs and automotive systems. Studies in the literature have addressed this challenge by proposing dynamic reconfiguration approaches (DRAs) for TEG arrays to mitigate power losses under NUTD conditions. However, the main issue with these DRAs is their reliance on numerous switches and sensors, which increases the system’s cost and complexity and necessitates regular maintenance. To provide a cost-effective solution, this paper introduces an innovative approach to designing a One-time Unified Configuration (OUC) for TEG arrays as an alternative to the standard series–parallel (SP) arrangement. This approach formulates an optimization problem to establish OUC as a unique layout for the TEG array under multiple NUTDs. The L-SHADE optimizer is tailored to determine the OUC layout that fits multiple NUTDs simultaneously. The yielded OUC ensures a consistent temperature distribution among the parallel strings of the TEG arrays, thereby maximizing the overall power output. The proposed OUC is rigorously implemented and tested on both symmetrical (9 × 9) and asymmetrical (10 × 15) TEG arrays and compared with DRA. Additionally, it is validated through a hardware setup involving a (5 × 5) TEG array under varying NUTDs. The results demonstrate a remarkable enhancement in TEG array output power with gains exceeding 10% compared to the standard SP configuration. Furthermore, the OUC eliminates the need for switches and sensors, resulting in cost savings of approximately 1498.5$ and 2775$ for the (9 × 9) and (10 × 15) TEG arrays, respectively, compared to DRA.

An Analytical Model for Electrochemical Tubular Flow Reactors

This paper introduces the first analytical model designed for tubular electrochemical flow reactor, enabling a detailed examination of how reactor geometry and material selection impact performance. The model revealed that certain conditions, such as high electrode resistance relative to charge transfer, electrolyte, and separator resistance, can lead to uneven current distributions and reduced electrode utilization. The model highlights a critical electrode radius, dependent on reactor geometry and material properties, that minimizes the Area Specific Resistance (ASR) while minimizing reactor size. Additionally, it was found that the ASR increases with reactor length, but this effect can be mitigated by using highly conductive electrodes, thus allowing for enhanced power output. These insights provide a foundation for future research and the development of more efficient tubular reactor designs.

Intercalation of V2O5 and Polypyrrole into a Graphene Oxide Layer: A Hybrid Multifunctional Photothermal Structure for Efficient Solar Evaporation, Water Purification, Disinfection, and Power Production.

Development of a hybrid multifunctional photothermal structure with multifunctional capabilities is deliberated as an effective approach for harvesting abundant solar energy for sustainable environmental applications. Achieving enhanced solar to thermal conversion efficiency utilizing a suitably designed, environmentally compatible thermal management structure however remains a significant challenge. Herein, we report the intercalation of V2O5 and polypyrrole into a graphene oxide layer to design a hybrid photothermal assembly (PPy-V2O5-GO) and its multifunctional proficiencies. The hybrid photothermal structure demonstrated synergistic photothermal conversion, buoyant porous structure sustaining water transmission, and efficient steam release. V2O5 and polypyrrole-intercalated optimized graphene oxide structure attained an evaporation rate of 1.9 kg m-2 h-1 with a conversion efficiency of 92% under 1 sun solar radiation. At maximum, the assembly's surface temperature hit 64 ± 2 °C, suggesting its suitability as a solar water purifier. Outdoor experiments suggest the evaporator assembly's capability to accumulate a total output of 15 kg m-2 over a single day. Cell viability investigations revealed strong antimicrobial properties of PPy-V2O5-GO against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, eliminating nearly all under 1 sun, making it a potential candidate for photothermal therapy. Furthermore, when combined with a commercial thermoelectric module, the framework displayed exceptional photothermal conversion efficiency, hinting at its potential for electrical power generation. The integration of PPy-V2O5-GO with a Bi2Te3-based thermoelectric module significantly boosted the thermoelectric generator's performance, offering an enhanced power output of 2.8 mW and a high power density of 1.24 mW/cm2, making them suitable for off-grid or remote-area application. Overall, the PPy-V2O5-GO photothermal assembly's stability, lack of leaching, effectiveness in producing pure water from seawater, antimicrobial efficacies, and recyclability make it an excellent choice for sustainable water treatment and power generation.

Dynamic performance enhancement in 2D and 3D curved flexible photovoltaic modules: Mismatch loss analysis and cell interconnection configurations optimization

The integration of photovoltaic (PV) technology into curved-surface buildings holds promise for energy-efficient eco-cities. However, the surface irradiance field of curved PV modules is uneven, and the distribution varies with the relative position to the sun and the surface shape. In this study, the dynamic irradiance field distributions of 2D and 3D curved PV modules are investigated. Based on this, 3 PV cell interconnection methods are proposed in conjunction with the irradiance balance principle. The electrical performance and power loss mechanisms are analyzed, and the dynamic adaptability, orientation adaptability, and geometric adaptability are evaluated. The results show diverse irradiance field patterns under different central angle conditions: uniform distribution in the north-south or east-west direction, while Gaussian distribution in other directions. Appropriate PV cell interconnection methods for 2D curved PV modules can effectively reduce mismatch losses, demonstrating significant enhancement in power output, up to 1721.21 Wh and 1604.10 Wh respectively. However, for 3D curved PV modules, the 3 interconnection methods fail to effectively adapt to the dynamic variation in irradiance, thus unable to fully exploit the power generation potential. In-depth investigation of mismatch losses in this study contributes to improving the reliability and economic viability of curved PV module, promoting its commercial application.