Power Loss Rate Research Articles

Evaluation of electric vehicle power routing and charging analysis using artificial neural network synchronized with 5G-network

To motivate the advanced National Clean Air Program (NCAP) strategy announced by the Indian Government in 2017, automizing the routing control on electric vehicle (EV) is a challenging area. According to the public authority guideline, the air contamination issues over the nation focus on accomplishing a 20% to 30% decrease in vehicular outflows in 2024 by enhancing EV mobility. However electric vehicle's limitations on battery capacity and route strategy to charging stations to preserve an adequate level of battery charge still need automized communication strategy. Fixed route solutions might not always be executable because battery consumption varies on several external factors. To better fit the real situation, this study proposes the notion of breaking down the self-adaptive online routing by encountering automatic path detection concerning battery efficiency with adaptive charging decisions. An inventory control-style charging technique is suggested to account for stochastic battery use. In the proposed work, by using an artificial neural network, the power demand and energy consumption of the EV world will be monitored and controlled by using 5G coverage on the smart city evolution. The obtained simulation analysis confirms that in comparison to current conventional and fixed tariff schemes, 5G accompanied EV accomplish an examined rate of SoC charge around 19.95 MW holding a peak range of 108.96 MW. Also, an evaluated typical power loss rate of 2.873 kWH which is less than 11.95% through frequency band analysis with signal-to-noise ratio and downlink power utilization.

Enhanced MPPT approach for grid-integrated solar PV system: Simulation and experimental study

The global solar energy utilization has significantly risen, mostly due to the technological, economic, and environmental advantages it offers, particularly through the implementation of photovoltaic (PV) systems. The energy output of PV systems is contingent upon climate conditions. A new hybrid two-stage maximum power point tracking (MPPT) system developed to optimize power extraction and increase efficiency in PV systems. The system consists of two stages: a perturb and observe (P&O) MPPT for regulating the reference voltage in the first stage, and an enhanced model reference adaptive controller (EMRAC) for adjusting the DC-DC converter duty cycle in second stage. This system is designed primarily for 100.7 kW three-phase grid-integrated PV systems operating in environments with rapidly changing solar irradiation and temperature levels. In order to demonstrate efficacy of the suggested approach, a probabilistic evaluation is conducted across three levels of uncertain scenarios, namely ropp, step irradiance profile, and rapid changing irradiation and temperature profile. The proposed approach attained maximum power point (MPP) in 0.11 s and had an average tracking efficiency of 98.28 %. Quantitative, statistical, comparative and experimental analyses utilizing the dSPACE 1202 reveal the effectiveness of the proposed control strategy and demonstrate the superior performance over P&O, INC and ANN based on the power output, response time, power loss, efficiency, and error rates.

A study on power supply restoration strategy considering flexible resource regulation ability

AbstractThe rapid development of new energy technology can make this type of energy the primary power source in the future. However, new energy power generation is considerably affected by the environment, resulting in intermittent and fluctuating characteristics. Given the shortage of power generation in urban distribution networks during extreme weather, a study on power supply restoration strategy considering flexible resource regulation ability is proposed in this study. First, the typical adjustable flexible resources, air conditioners, and electric vehicles in urban distribution networks are modeled, and their adjustment ability is evaluated. Second, on the basis of the evaluation results, the optimal power supply recovery path is solved to ensure the power supply of essential loads in the distribution network. Last, the IEEE 33‐bus system proves that this method can quickly find the optimal path of power supply recovery and effectively reduce the power loss rate of essential loads, thus improving the toughness of urban distribution networks.

A Study on the Maximum Reliability of Multi-UAV Cooperation Relay Systems.

This paper studies the maximum reliability of multi-hop relay UAVs, in which UAVs provide wireless services for remote users as a coded cooperative relay without an end-to-end direct communication link. In this paper, the analytical expressions of the total power loss and total bit error rate are derived as reliability measures. First, based on the environmental statistical parameters, a LOS probability model is proposed. Then, the problem of minimizing the bit error rate of static and mobile UAVs is studied. The goal is to minimize the total bit error rate by jointly optimizing the height, elevation, power and path loss and introducing the maximum allowable path loss constraints, transmission power allocation constraints, and UAV height and elevation constraints. At the same time, the total path loss is minimized to achieve maximum ground communication coverage. However, the formulated joint optimization problem is nonconvex and generally difficult to solve. Therefore, we decomposed the problem into two subproblems and proposed an effective joint optimization iteration algorithm. Finally, the simulation results are given, and the analysis shows that the optimal height of different reliability measures is slightly different; thus, using the mobility of UAVs can improve the reliability of communication performance.

Voltage and Reactive Power-Optimization Model for Active Distribution Networks Based on Second-Order Cone Algorithm

To address the challenges associated with wind power integration, this paper analyzes the impact of distributed renewable energy on the voltage of the distribution network. Taking into account the fast control of photovoltaic inverters and the unique characteristics of photovoltaic arrays, we establish an active distribution network voltage reactive power-optimization model for planning the active distribution network. The model involves solving the original non-convex and non-linear power-flow-optimization problem. By introducing the second-order cone relaxation algorithm, we transform the model into a second-order cone programming model, making it easier to solve and yielding good results. The optimized parameters are then applied to the IEEE 33-node distribution system, where the phase angle of the node voltage is adjusted to optimize the reactive power of the entire power system, thereby demonstrating the effectiveness of utilizing a second-order cone programming algorithm for reactive power optimization in a comprehensive manner. Subsequently, active distribution network power quality control is implemented, resulting in a reduction in network loss from 0.41 MW to 0.02 MW. This reduces power loss rates, increases utilization efficiency by approximately 94%, optimizes power quality management, and ensures that users receive high-quality electrical energy.

The impact of variation in water flow rate and temperature on reliability analysis of run of the river power plants

AbstractA run‐of‐the‐river power plant is a renewable energy source used for electricity production. Its power output depends on the varying water flow rate over time, which can impact the reliability of the electric network. Previous research has not studied the effects of water flow rate and temperature variations on the hazard rate of the plant's components. This paper addresses this gap by investigating the impact of these variations on the reliability of electric networks with run‐of‐the‐river power plants. The analysis considers the hazard rates of the plant's components, incorporating the relationship between hazard rate and temperature based on the Arrhenius law. Parameters such as power output, current, power loss, operating temperature, and hazard rate are calculated for different water flow rates and ambient temperatures. Numerical simulations on a test system are conducted to examine the influence of water flow rate and temperature on the reliability indices of the electric network. The results demonstrate that water flow rate and temperature significantly affect the hazard rates of run‐of‐the‐river power plants. This highlights the need to consider these factors in the reliability analysis of electric networks incorporating these renewable resources.

Remaining useful life prediction of vehicle-oriented PEMFC systems based on IGWO-BP neural network under real-world traffic conditions

Accurately predicting the useful life can serve as a pivotal reference for effectively extending the lifespan of proton exchange membrane fuel cells (PEMFCs). Herein, this paper proposes a novel method that combines an improved grey wolf optimizer (IGWO) algorithm and a backpropagation (BP) neural network to predict the remaining useful life (RUL) of vehicle-oriented PEMFC systems using relative power loss rate (RPLR) as a health indicator under real-world traffic conditions. First, The Pearson correlation coefficient is used to analyze the correlation of various monitoring parameters and to verify the effectiveness of RPLR as a dynamic health indicator. Then, the IGWO-BP neural network-based prediction method is described and used to predict the RUL of PEMFC systems. Finally, the accuracy and reliability of the proposed method are validated against two separate datasets of PEMFC city buses operating under different traffic conditions. Compared with other methods, the proposed method has a relative error of less than 5 % and predicts a shorter RUL than the actual RUL. These findings illustrate that the proposed method has a high prediction accuracy and offers an early warning function, which is beneficial for practical applications.

Effects of Power Optimizer Application in a Building-Integrated Photovoltaic System According to Shade Conditions

A building-integrated photovoltaic (BIPV) system produces power using photovoltaic (PV) modules as building exterior materials, whose architectural performance serves the same functions as those of existing building materials. Most relevant studies targeted general PV modules used in the building-mounted and -attached types. This study aims to integrate the building elevation-type BIPV system and exterior materials to secure both exterior material performance and PV electrical performance by embedding a power optimization device in an integrated system of BIPV modules and exterior materials. Thus, the advantages of economy, safety, aesthetics, and ease of maintenance can be achieved. In this study, experiments were conducted on elevation-type BIPV modules with and without a power optimizer, that is, a DC/DC converter, under various shade conditions, and the power loss rate of the BIPV system was analyzed. The power optimizer-equipped BIPV system was experimentally observed to have a PV power-loss rate approximately 2–3 times lower than that of the BIPV system without a power optimizer when the shade ratio of one module was approximately 10–75%. This exterior material-integrated BIPV-specific power optimization device reduces dependence on fossil fuels for power production and improves energy sustainability, contributing to the spread of zero-energy buildings and carbon neutrality.

Abstract 12955: Shear-Dependent Changes in Blood Viscosity Negatively Affect Energetic Efficiency in Patient-Specific Models of the Fontan Circulation

Introduction: Since blood flow through the lungs is passive in patients with the Fontan circulation, cardiac output is sensitive to power loss through the pulmonary vasculature. Prior small in vitro studies of how changes in blood viscosity at venous shear rates (“non-Newtonian behavior”) affect power loss have yielded conflicting results. The purpose of this study was to evaluate the extent to which non-Newtonian behavior contributes to power loss in a large number of pediatric patient-specific models of the Fontan circulation. Hypothesis: Shear-dependent changes in blood viscosity cause increased power loss in the low-shear Fontan circulation. Methods: Pulmonary vascular geometry was segmented from clinical cardiac MRI images. Pressure and velocity fields were then calculated using computational fluid dynamic simulations. Cardiac index was set at 2 L/min/m2 to simulate a low cardiac output state. A constant viscosity model (“Newtonian”) was compared to a shear-dependent viscosity model (“non-Newtonian”). Power loss was calculated by simplified power loss (using bulk flow and pressure changes) and viscous dissipation rate (using element-wise shear rates and viscosities). Both metrics were indexed to adjust for cardiac output and body surface area. Wilcoxon signed-rank test was used to compare differences between the two viscosity models. Results: Twenty patients (mean 10.9 years, 35% female) were included. Mean viscosity was nearly 10-fold higher in the non-Newtonian vs. Newtonian simulations (mean non-Newtonian to Newtonian viscosity ratio 9.7, SD 0.6). Accordingly, power loss by both metrics was significantly larger for the non-Newtonian simulations ( Figure ). Conclusions: Shear-dependent increases in blood viscosity cause increased power loss in computational models of the Fontan circulation under low cardiac output conditions. Further studies are needed to evaluate the degree to which this correlates with clinical outcomes.

Analysis of Power Output During the Countermovement and Split-Squat Jump Across Loads and High-Volume Repetitions in Elite Athletes

The primary purpose of this study was to determine the rate of peak power (PP) loss during the countermovement jump (CMJ) and split-squat jump (SSJ) across various loads within a set of high repetitions. Eleven collegiate track and field athletes who had several years of resistance training experience and were trained in the two types of jumps completed the study. The participants completed a familiarization session and 2 data collection sessions. The CMJ and SSJ were completed in random order during session 1 and 2 separated by a minimum of 72 hours. Three loads using dumbbells took place in random order with each session including body weight only (BW0), body weight plus 15% (BW15) and body weight plus 30% BW(30) for the SSJ and BW(0), BW(25), and BW(50) for the CMJ. PP was determined using the PUSH 2.0 3D accelerometer worn at the waist, which was connected to an ipad app using Bluetooth. The participants completed 14 repetitions each set with 8 min rest between sets. Repetition 3 demonstrated the highest mean PP (PPmax) within the set. No significant decrease in PP was observed until repetition 6 (3.6% below PPmax) during the SSJ and repetition 8 (5.2% below PPmax) during the CMJ. These data indicate that 5 or less repetitions should be completed during the CMJ and 7 or less for the SSJ when training for PP. Using 10% reduction in PP as an effective level to train for power endurance, we recommend completing a minimum of 12 repetitions during the CMJ and a minimum of 10 repetitions for the SSJ.

FEM Modelling of the Heating Behaviour in Vibrothermography Based on Thermoelastic Damping on Crack Location

The paper aims to simulate the heat generation in crack location based on vibrothermography inspection. For this study, the thermoelastic damping effect was considered as the source of heat generation and the value of thermoelastic damping was determined. In simulation, the model of the specimen with crack was AL7075-T6. The vibrational frequencies were given at 20kHz, 24kHz and 28kHz, while the maximum amplitude was constant of 4.8nm. The results of temperature variation, stress, energy loss and heat flow rate on the crack location were obtained from the simulations which were performed by using ANSYS software. The ratio between power loss and heat flow rate was calculated and presented as the index for selecting the most suitable vibrational frequency in term of heat accumulation. The case study 20kHz was considered as the most suitable vibrational frequency for this study because the index ratio was higher than the case studies 24kHz, 28kHz at 6.29% and 9.14% respectively.

Prospects for creating a refined model of leakage current losses due to contamination on insulator surfaces

This paper is devoted to identifying the prospects for creating a model of leakage current losses due to contamination on insulator surfaces. The aim of this study was to find mathematical models that would describe leakage current losses accurately enough to assess their importance for the integrated power system of Ukraine. The existing, widely used methodology for calculating leakage current losses was evaluated and found to be inappropriate because it is based solely on the insulator resistance with a constant value of m, which does not reflect the actual situation. Therefore, in order to improve the existing model, another one is proposed, which takes into account all atmospheric phenomena that affect the conductivity on the insulator surface, including fog, drizzle, rain and dew, which are recorded using gradations. It was found that the wind speed and humidity of the contamination layer on the insulator surface have a significant impact. The graphs of the average power loss rate for a single wetting in a garland of insulators under different climatic conditions are presented. The methodology was used to calculate the power loss rate in a 35 kV AC network and is presented in the table. The results show that it is possible to dynamically determine losses depending on climatic conditions on insulators at any point, depending on the available meteorological data. The methodology for determining the conductivity of the contamination layer on the insulator surface has been revised. It is shown how the resistance of contamination is represented, the method of its calculation, which allows further determining the conductivity of contamination, and the effect of precipitation on the cleaning of the insulator surface from contamination. It is established that under direct precipitation, insulator cleaning is insignificant, and the humidity of the contamination layer increases, which increases its conductivity. The conclusions show that the model has a high potential and the need to take into account dielectric losses.

Comprehensive Analysis of the Impact of the Icing of Wind Turbine Blades on Power Loss in Cold Regions

Blade icing often occurs on wind turbines in cold climates. Blade icing has many adverse effects on wind turbines, and the loss of output power is one of the most important effects. With the increasing emphasis on clean energy around the world, the design and production of wind turbines tend to be large-scale. So this paper selected the 15 MW wind turbine provided by NREL (American Renewable Energy Laboratory) to study the influence of blade icing on output power. In this paper, a multi-program coupled analysis method named CFD-WTIC-ILM (CFD: Computational fluid dynamics; WTIC: Wind Turbine Integrated Calculation; ILM: Ice loss method) was proposed to analyze the whole machine wind turbine. Firstly, Fensap-ice was used to simulate the icing of the wind turbine blades, and then the icing results were input into WTIC for the integrated calculation and analysis of the wind turbine. Then, the WTIC calculation results were used to simulate SCADA (supervisory control and data acquisition) data and input into ILM to calculate the power loss. Finally, this paper analyzed the comprehensive influence of icing on output power. The calculation results show that the ice mainly accumulates on the windward side of the blade. Icing has a great influence on the aerodynamic characteristics of the airfoil, leading to a significant decrease in the power curve. The rated wind speed is pushed from 10.59 m/s to 13 m/s. The power loss of the wind turbine in the wind speed optimization stage is as high as 37.48%, and the annual power loss rate caused by icing can reach at least 22%.

A normalized Haar wavelet transformation based firefly optimization algorithm for power transmission line fault detection problems

ABSTRACT Through transmission lines (TLs), an electric power transmission system has been able to transmit power from generating stations to consumers. During transmission, various kinds of malfunctions take place and they are termed as a fault. Although fault is undesirable, it is unavoidable event hampering the smooth functioning of the power system. In power transmission systems, and a large number of voltage and current signal, distortions take place due to faults. Faults occur in power TL causing power supply interruption. Several fault detection techniques have been presented by researchers to detect a fault in TL. However, the time required to locate the fault remained higher and the power loss rate (PLR) was not reduced. To overcome these issues and identify faults in electrical power TL, Haar wavelet feature extraction-based firefly optimized fault detection (HWFE-FFOFD) method has been introduced. The power TL signal sample has been taken as an input. Zero-mean normalization is the pre-processing approach that converts the transmission signal sample into a specified range. To extort features (i.e. voltages and current values) with higher accuracy, the normalized signal has been given to Haar Wavelet Transform. Then, the extracted features at different time instants have been given to the firefly optimized fault detection (FFOFD) algorithm. In the FFOFD algorithm, extracted features have been considered as firefly populations. The FFOFD algorithm functions with the flashing behavior of a firefly. At last, the firefly position has been updated and ranked according to light intensity to detect a fault in electrical power TL. In this manner, the fault detection time (FDT) gets reduced using HWFE-FFOFD method. HWFE-FFOFD method is evaluated in FEA, FDT, and PLR. From the experimental results obtained, it can be confirmed that the HWFE-FFOFD method has been able to enhance accuracy by 14% and minimize time by 26% and PLR by 62% when compared to conventional methods.

A novel robust maximum power extraction framework for sustainable PV system using incremental conductance based MRAC technique

AbstractThis study proposes a maximum power point tracking (MPPT) approach with two components: an Incremental Conductance (INC) MPPT for reference voltage regulation and a Model Reference Adaptive Controller (MRAC) for adjusting the duty cycle of the DC‐DC converter switch. A robustness test is performed on the system considering real‐world situations that involve an abrupt change in atmospheric conditions with load uncertainties. The probabilistic load distribution analysis is accomplished through levels of uncertainty (i.e., Probabilistic DOWN and UP) to guarantee the operation of the proposed INC‐MRAC controller while generating unexpected disturbances in the system. Using MATLAB/Simulink, the performances of the novel INC‐MRAC MPPT are comparatively analyzed with PO, INC, VSSPO, and ANN under realistic case studies in seven states. After comparative analysis, it is evident that the proposed MPPT offers less tracking time, i.e., 3.8 ms, to track maximum power point (MPP) with negligible steady‐state oscillation and ripples. It is about 3, 7, 9, and 10 times faster than ANN, VSSPO, INC and PO, respectively. Moreover, the tracking efficiency of the proposed controller is up to 99.63% as well as overall efficiency of the system is more than 98%. The tracking power loss and error rate in finding MPP for the proposed controller is the lowest among all state‐of‐the‐art MPPT approaches. Finally, the effectiveness of the proposed INC‐MRAC approach is experimentally validated by employing a real‐time simulator OPAL‐RT (OP4510). The study helps in environmental protection and participation in sustainable development.

Coordinated volt/VAR control for photovoltaic inverters: A soft actor-critic enhanced droop control approach

The reactive power capacity of photovoltaic inverters can be utilised to minimise power loss and mitigate rapid voltage fluctuations in an active distribution network. This paper proposes a coordinated volt/VAR control framework that simultaneously optimises the base reactive power output of photovoltaic inverters and the voltage intercept of each droop control function in the central hierarchy based on whole-system information to minimise the power loss. The photovoltaic inverters use the optimised droop function to eliminate the voltage violation based on the real-time local information in the local hierarchy. Subsequently, the optimisation problem is formed as a Markov decision process and solved using an improved deep reinforcement learning algorithm called a soft actor-critic to achieve fast control with full consideration of uncertainties. Thus, the proposed method can simultaneously guarantee the cooperation and rapidity of the control performance to minimise power loss and quickly respond to real-time voltage fluctuations. Case studies were implemented using IEEE 33-bus and 123-bus distribution networks. The comparison results demonstrate that the proposed method can reduce the power loss and voltage violation rate by up to 12.3% and 2.71%, respectively, compared with other benchmark methods, which demonstrates the superiority of the proposed method in terms of power loss minimisation and voltage fluctuation mitigation.

Methodology for Counter Torque, Power Loss, and Frictional Heat for Brush Seals Under Eccentric Transients

Turbomachinery brush seals are used for achieving close clearance control with the aid of flexible bristles. Frictional forces between bristle tips and rotor surfaces induce counter torque, power loss, and heat generation during turbomachinery transients; all of these determine the overall efficiency, operation life, and stability of turbomachinery application. As a result of manufacturing tolerances, rotor dynamics-induced shaft deflections, and additional gyroscopic loads in aviation engines, eccentric rotor rub occurs toward brush seals in transients, causing partial rotor–seal contact with nonlinear radial interference and uneven tip force distribution. There is an inherent error in the current power loss and frictional heat rate analyses, as well as in counter torque methodologies, since they do not account for the uneven tip force distribution. In this study, a nonlinear radial interference profile of eccentric rotor contact conditions has been derived and its effect on contact angle has been examined with a comparative analysis with concentric rotor expansion. The methodology for counter torque, power loss, and generated frictional heat rate analyses has been detailed, and eccentric condition formulations have been derived with the surface integration of dynamic bristle tip force functions adopted from brush seal dynamic stiffness tests. Analysis of nonlinear interference and uneven contact force profiles has been conducted based on the combined effects of assembly conditions and eccentricity levels. Results obtained using the developed closed-form equations for eccentric rotor contact are compared with concentric rotor expansion and simple eccentric rotor rub analyses, which do not account for uneven tip forces.

Research on Parameter Design Method and Motion Characteristics of a Ball Cage Flexible Joint

The flexible joint is an important part in ultra-short-radius drilling tools, and its structural parameters and motion characteristics are key factors affecting the success of drilling. In this work, a new type of ball cage flexible joint, which is applied in 5″ and 5.5″ cased wells, was proposed based on the working principle of the ball cage universal joint. A structural parameter design method for the ball cage flexible joint was established according to the geometric coordination relation and material strength theory. Using this new method, the length, diameter, and window size of the ball cage flexible joint were analyzed. The multi-body motion process was further analyzed using a multi-body dynamics method, and then the motion characteristics, such as impact contact force, isokinetic characteristics, transfer efficiency, deflection torque and so on, were studied. Based on the above analyses, the structural parameters of the designed joint were optimized by means of the orthogonal test method. Results demonstrate that the experimental ball cage flexible joint has excellent isokinetic transmission characteristic, which can effectively suppress vibration and shock caused by changes in rotational speed. The transmission efficiency of the structure was 89.8%, while the power loss rate was 0.102%. According to the orthogonal test analysis, the optimal structure of the flexible joint has a ball seat diameter of 80 mm, a ball head diameter of 62 mm, and a ball key diameter of 16 mm. It is important to note that the ball key diameter was the most influential factor on the flexible joint internal contact force. The ball key contact force varied periodically, and there was a significant phase difference between the contact forces of different balls. On the other hand, with an increase in the flexible joint working angle, the deflection torque increased gradually, and the vibration amplitude of the torque increased. This work can provide reference for the parameter optimization design of the new flexible joint.

Impacts of grass planting density and components on overland flow hydraulics and soil loss

AbstractAlthough abundant studies have confirmed the positive effect of vegetation on runoff and soil erosion reduction, few studies have clarified the effects of planting density and its components (aboveground parts and roots) on slope runoff and soil erosion mechanisms. A series of field experimental plots were constructed on two slopes (3°, 6°), including a bare land plot as the control, three grassed plots with three grass (Agropyron cristatum) planting densities of 20 cm × 20 cm, 15 cm × 15 cm, and 10 cm × 10 cm, and a plot without aboveground parts, to examine runoff and soil erosion process under simulated overland flow of 4, 8, 12, and 16 L min−1. The runoff regime was transformed from supercritical‐turbulent flow to subcritical‐laminar flow with increasing planting density. Grass significantly reduced the runoff rate (RR), velocity (V), shear stress (τ), stream power (ω), and soil loss rate (SLR), with average reductions of 38.6%, 56.6%, 76.5%, 87.6%, and 61.9%, respectively. The aboveground parts contributed 74.1% and 75.1% of the total reduction in RR and V, respectively, while the grass roots contributed to 84.9%, 89.7%, 84.9%, and 69.7% of the reductions in Reynolds number, τ, ω, and SLR, respectively. RR, V, τ, ω, and SLR were significantly affected by slope, inflow discharge, root density, and the ratio of grass stem area to plot area. The runoff–sediment relationship changed from positively exponential function to linear and power functions with the planting density increased. Grass significantly weakened the sensitivity of soil erosion by reducing soil erodibility and improving critical hydrodynamic triggering soil erosion. This study improved the understanding of grass controlling soil and water loss, and the plants with well‐developed roots and planting space of 10–15 cm are preferred to provide a scientific reference for revegetation strategy.

Degradation of Edge‐Defined Film‐Fed Silicon Glass–Glass Modules on Florida Rooftop After 22 Years

Thin silicon () adoption can provide significantly lower cost. Kerfless technologies provide thin wafers while preventing material from being wasted. Understanding how this family of processing influences module reliability is important. A set of four edge‐defined film‐fed growth (EFG) silicon modules from a ten‐module system in Florida is measured after 22 years of exposure. Power loss rates of 0.58–0.78% year−1 are measured for three modules, while a rate of 1.32% is measured for a module with severe delamination and corrosion. Short‐circuit current degrades between 10.7% and 13.1% for all modules. The losses are primarily optical and recombination based; however, series and shunt resistance effects play a non‐negligible role. Pre‐existing recombination losses exist but are exacerbated via degradation. Optical losses in short‐circuit current are due in part to encapsulant yellowing. Electroluminescence (EL) images display the effects of processing on bulk quality by clearly showing lines of alternating brightness along the wafer length. To the authors’ knowledge, this is the first article displaying suns– data, effective lifetime versus excess carrier density data, and module EL images for EFG silicon‐based modules.