Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938712
J. Elsworth, Gerald Robinson, J. Ness, Joseph H. Cain
Industry stakeholders have to date largely overlooked both the critical role and uniqueness of bolted joints found in solar PV systems. Bolted joints seen in solar PV racking and module mounting lack the technological maturity exhibited in comparable industries to deliver low cost and high reliability solutions critically needed for further advancement of the industry. As a result they have regularly failed, which can have results ranging from unexpected system maintenance to entire PV system failures--in severe weather events and in normal operating conditions. This paper will overview and categorize the current state of PV bolted j oint technologies, provide an engineering analysis of failure modes, identify codes and standards gaps leading to inconsistent bolted joint application in the field, summarize and publicize data gathered from a surveying and interviewing effort on field failures, share results of structural lab physical testing of common PV system bolted joint typets and the CFD flow models they inform, and develop a lifetime cost accounting model and tool for determining the cost impacts of various bolted joint and hardening options. The paper format is that of a technical guidance document, backed by empirical evidence aimed at near and long-term influence; product engineers for near-term and codes and standards committees for long-term advancement.
{"title":"The Nuts and Bolts of PV: Maturing Solar PV Racking and Module Mounting Critical Bolted Joint Technologies for LCOE Reductions and Increased Reliability","authors":"J. Elsworth, Gerald Robinson, J. Ness, Joseph H. Cain","doi":"10.1109/pvsc48317.2022.9938712","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938712","url":null,"abstract":"Industry stakeholders have to date largely overlooked both the critical role and uniqueness of bolted joints found in solar PV systems. Bolted joints seen in solar PV racking and module mounting lack the technological maturity exhibited in comparable industries to deliver low cost and high reliability solutions critically needed for further advancement of the industry. As a result they have regularly failed, which can have results ranging from unexpected system maintenance to entire PV system failures--in severe weather events and in normal operating conditions. This paper will overview and categorize the current state of PV bolted j oint technologies, provide an engineering analysis of failure modes, identify codes and standards gaps leading to inconsistent bolted joint application in the field, summarize and publicize data gathered from a surveying and interviewing effort on field failures, share results of structural lab physical testing of common PV system bolted joint typets and the CFD flow models they inform, and develop a lifetime cost accounting model and tool for determining the cost impacts of various bolted joint and hardening options. The paper format is that of a technical guidance document, backed by empirical evidence aimed at near and long-term influence; product engineers for near-term and codes and standards committees for long-term advancement.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115273761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938740
K. Tan, Joseph A. Azzolini, William J. Parquette, Christian R. Polo, Meng Tao
Practically all of today’ photovoltaic (PV) systems employ a maximum power point tracker (MPPT) to maximize the power output of a PV array under different temperature, weather, and irradiance conditions. We proposed and demonstrated a load-matching PV system which performs maximum power point tracking by varying the number of loads connected to the PV array, without a conventional MPPT. However, the control algorithm in our system makes many unsuccessful switches as it does not know the optimum switch points for the loads. This paper presents an intelligent algorithm that can estimate the optimum switch point before attempting a switch. Simulation and experimental results show that the proposed algorithm is effective in minimizing unsuccessful switches. These results demonstrate an improved algorithm for maximum power point tracking through load management.
{"title":"An Intelligent Algorithm for Maximum Power Point Tracking in PV Systems through Load Management","authors":"K. Tan, Joseph A. Azzolini, William J. Parquette, Christian R. Polo, Meng Tao","doi":"10.1109/pvsc48317.2022.9938740","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938740","url":null,"abstract":"Practically all of today’ photovoltaic (PV) systems employ a maximum power point tracker (MPPT) to maximize the power output of a PV array under different temperature, weather, and irradiance conditions. We proposed and demonstrated a load-matching PV system which performs maximum power point tracking by varying the number of loads connected to the PV array, without a conventional MPPT. However, the control algorithm in our system makes many unsuccessful switches as it does not know the optimum switch points for the loads. This paper presents an intelligent algorithm that can estimate the optimum switch point before attempting a switch. Simulation and experimental results show that the proposed algorithm is effective in minimizing unsuccessful switches. These results demonstrate an improved algorithm for maximum power point tracking through load management.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121810560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/PVSC48317.2022.9938646
N. Nouri, C. Valdivia, M. Beattie, J. Krich, K. Hinzer
Photonic power converters (PPC) convert narrow-band light into electricity via the photovoltaic effect. In this study, we discussed optical design considerations of thin InAlGaAs PPCs with integrated pyramidal nano-textured back reflectors (BRs) under 1310 nm illumination. Simulation results using the finite difference time domain method revealed that multiple combinations of design space parameters yield similar total absorptance at 1310 nm but with different absorptance spectra. A tolerance study performed using one optimized design showed that a 70 nm variation in device thickness shifted BR-induced resonances from constructive to destructive interference and a 50 nm variation of the height and base width of nano-pyramids dropped the absorptance by more than 25% (absolute). Among all simulated designs, those with overlapping resonances around the target wavelength that incorporated a thin-film antireflection coating were the least sensitive to variations in the illumination wavelength.
{"title":"Optical Design Considerations for Thin Photonic Power Converters with Textured Back Reflector","authors":"N. Nouri, C. Valdivia, M. Beattie, J. Krich, K. Hinzer","doi":"10.1109/PVSC48317.2022.9938646","DOIUrl":"https://doi.org/10.1109/PVSC48317.2022.9938646","url":null,"abstract":"Photonic power converters (PPC) convert narrow-band light into electricity via the photovoltaic effect. In this study, we discussed optical design considerations of thin InAlGaAs PPCs with integrated pyramidal nano-textured back reflectors (BRs) under 1310 nm illumination. Simulation results using the finite difference time domain method revealed that multiple combinations of design space parameters yield similar total absorptance at 1310 nm but with different absorptance spectra. A tolerance study performed using one optimized design showed that a 70 nm variation in device thickness shifted BR-induced resonances from constructive to destructive interference and a 50 nm variation of the height and base width of nano-pyramids dropped the absorptance by more than 25% (absolute). Among all simulated designs, those with overlapping resonances around the target wavelength that incorporated a thin-film antireflection coating were the least sensitive to variations in the illumination wavelength.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125210463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938681
Mario Martínez, S. Svatek, Carlos Bueno-Blanco, D. Lin, Inés Durán, A. Martí, E. Antolín
Transition metal dichalcogenide (TMDC) semiconductors are promising materials for the manufacture of ultrathin solar cells due to their optoelectronic properties and their potential for low-cost fabrication. However, they still present several technological challenges, such as the development of ohmic contacts. The most common contact technology is based on the deposition of metals on the TMDC and subsequent annealing. It is known that this process damages the crystalline structure of the TMDC, leading to Fermi level pinning at the contact interface (Schottky barrier). In this work we explore an easy-to-implement ohmic contact for TMDC solar cells, in which a very flat metal surface has been prepatterned on the substrate and the TMDC laminae are transferred onto it. The TMDC atomic layers remain intact, and they are joined to the metal surface only by van der Waals forces. If a metal of suitable working function is chosen, an ohmic contact is produced without the need of thermal annealing. Using the transfer length method (TLM) we demonstrate that it is possible to obtain contact resistances in the order of 1.10-3Ω. cm2 for n and p doped MoS2, which means that this simple fabrication method for van der Waals metal/TMDC contacts produces sufficiently low series resistance for one-sun applications.
{"title":"A simple approach to ohmic contacts for transition metal dichalcogenide solar cells","authors":"Mario Martínez, S. Svatek, Carlos Bueno-Blanco, D. Lin, Inés Durán, A. Martí, E. Antolín","doi":"10.1109/pvsc48317.2022.9938681","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938681","url":null,"abstract":"Transition metal dichalcogenide (TMDC) semiconductors are promising materials for the manufacture of ultrathin solar cells due to their optoelectronic properties and their potential for low-cost fabrication. However, they still present several technological challenges, such as the development of ohmic contacts. The most common contact technology is based on the deposition of metals on the TMDC and subsequent annealing. It is known that this process damages the crystalline structure of the TMDC, leading to Fermi level pinning at the contact interface (Schottky barrier). In this work we explore an easy-to-implement ohmic contact for TMDC solar cells, in which a very flat metal surface has been prepatterned on the substrate and the TMDC laminae are transferred onto it. The TMDC atomic layers remain intact, and they are joined to the metal surface only by van der Waals forces. If a metal of suitable working function is chosen, an ohmic contact is produced without the need of thermal annealing. Using the transfer length method (TLM) we demonstrate that it is possible to obtain contact resistances in the order of 1.10-3Ω. cm2 for n and p doped MoS2, which means that this simple fabrication method for van der Waals metal/TMDC contacts produces sufficiently low series resistance for one-sun applications.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116933283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938879
Alexandre Chapotot, J. Arias‐Zapata, Tadeáš Hanuš, B. Ilahi, Nicolas Paupy, Valentin Daniel, Zakaria Oulad El Hmaidi, Jérémie Chrétien, G. Hamon, M. Darnon, A. Boucherif
Epitaxial thin film detachment and substrate reuse is one of the promising approaches to reduce the weight and the cost of triple junction (3J) solar cells on Ge substrate for both terrestrial and space PV. This approach is based on epitaxial growth of high-quality solar cell materials on porosified Ge substrate. The mesoporous layer created by electrochemical etching undergoes thermal induced reconstruction leading to the formation of voided weak layer suitable for epilayers detachment. This approach is low-cost, scalable to large surfaces and allows the substrate reuse for several epitaxial cycles upon appropriate reconditioning. Accordingly, the success of the reconditioning step is conditional to both reliability and cost-effectiveness. In this context, we report the first successful proof-of-concept of Ge substrate reuse for epitaxy after the epilayer detachment. We demonstrate that chemical etching with HF-based mixture allows to recondition the detached substrate providing a low surface roughness of 1.3 nm without any CMP step. The reconditioned substrate was then porosified giving rise to homogenous porous layer suitable for epitaxial regrowth. A second growth cycle has been successively performed on the reconditioned and reporosified substrate. The epitaxial Ge layer from the second cycle is found to have high crystalline quality and low surface roughness as revealed by X-ray diffraction and atomic force microscopy investigations. Our results demonstrate a CMP-free reliable Ge substrate reconditioning process for epitaxy, which paves the way to the substrate multi-reuse for triple junction solar cell cost-reduction.
{"title":"Multiple substrate reuse: a straightforward reconditioning of Ge wafers after porous separation","authors":"Alexandre Chapotot, J. Arias‐Zapata, Tadeáš Hanuš, B. Ilahi, Nicolas Paupy, Valentin Daniel, Zakaria Oulad El Hmaidi, Jérémie Chrétien, G. Hamon, M. Darnon, A. Boucherif","doi":"10.1109/pvsc48317.2022.9938879","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938879","url":null,"abstract":"Epitaxial thin film detachment and substrate reuse is one of the promising approaches to reduce the weight and the cost of triple junction (3J) solar cells on Ge substrate for both terrestrial and space PV. This approach is based on epitaxial growth of high-quality solar cell materials on porosified Ge substrate. The mesoporous layer created by electrochemical etching undergoes thermal induced reconstruction leading to the formation of voided weak layer suitable for epilayers detachment. This approach is low-cost, scalable to large surfaces and allows the substrate reuse for several epitaxial cycles upon appropriate reconditioning. Accordingly, the success of the reconditioning step is conditional to both reliability and cost-effectiveness. In this context, we report the first successful proof-of-concept of Ge substrate reuse for epitaxy after the epilayer detachment. We demonstrate that chemical etching with HF-based mixture allows to recondition the detached substrate providing a low surface roughness of 1.3 nm without any CMP step. The reconditioned substrate was then porosified giving rise to homogenous porous layer suitable for epitaxial regrowth. A second growth cycle has been successively performed on the reconditioned and reporosified substrate. The epitaxial Ge layer from the second cycle is found to have high crystalline quality and low surface roughness as revealed by X-ray diffraction and atomic force microscopy investigations. Our results demonstrate a CMP-free reliable Ge substrate reconditioning process for epitaxy, which paves the way to the substrate multi-reuse for triple junction solar cell cost-reduction.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117119482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938805
N. Anderson, V. Tatsiankou, K. Hinzer, R. Beal, H. Schriemer
Using a recently-created database for Ottawa, Canada, a 9-month longitudinal study of the solar irradiance, measured with a custom spectral pyranometer every 250ms, was conducted with a specific focus on comparing the narrowband and broadband response to the temporal variability. Deterministic diurnal and orbital dependencies of the spectral irradiance were removed by clear sky normalization, and the resulting clear sky index was forward differenced across time steps ranging from the sub-second to ~30 minutes. The stochastic behavior of this spectral clear sky index increment was assessed by kernel density estimates of the probability distributions for data from each of the nine narrow wavelength channels of the spectral pyranometer and the derived broadband global horizontal irradiance (GHI). Scaling analyses of their peak densities and their full widths at half maximum (FWHM) with increment time step revealed power law scaling with consistent stationary breaks at very-short and short times. Broadband scaling was consistent with some narrowband dependencies, but not with others, which may reflect the wavelength dependence of different sky conditions. The existence of three distinct scaling regimes, each of which coincides with an operationally significant time period (primary/secondary control, automatic generation control, and real time market dispatch), has implications for short term probabilistic forecasting.
{"title":"Probabilistic Assessment of Narrowband vs Broadband Solar Irradiance Temporal Variability in Ottawa","authors":"N. Anderson, V. Tatsiankou, K. Hinzer, R. Beal, H. Schriemer","doi":"10.1109/pvsc48317.2022.9938805","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938805","url":null,"abstract":"Using a recently-created database for Ottawa, Canada, a 9-month longitudinal study of the solar irradiance, measured with a custom spectral pyranometer every 250ms, was conducted with a specific focus on comparing the narrowband and broadband response to the temporal variability. Deterministic diurnal and orbital dependencies of the spectral irradiance were removed by clear sky normalization, and the resulting clear sky index was forward differenced across time steps ranging from the sub-second to ~30 minutes. The stochastic behavior of this spectral clear sky index increment was assessed by kernel density estimates of the probability distributions for data from each of the nine narrow wavelength channels of the spectral pyranometer and the derived broadband global horizontal irradiance (GHI). Scaling analyses of their peak densities and their full widths at half maximum (FWHM) with increment time step revealed power law scaling with consistent stationary breaks at very-short and short times. Broadband scaling was consistent with some narrowband dependencies, but not with others, which may reflect the wavelength dependence of different sky conditions. The existence of three distinct scaling regimes, each of which coincides with an operationally significant time period (primary/secondary control, automatic generation control, and real time market dispatch), has implications for short term probabilistic forecasting.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117223586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/PVSC48317.2022.9938907
A. Law, F. Bukhari, L. Jones, A. Abbas, J. Walls
The cover glass sheet on solar modules can cause reflection losses as well as soiling build-up. Reflection losses can be addressed with anti-reflection (AR) coatings, whilst soiling is removed by mechanical cleaning processes that are effective but can have adverse effects on surface coatings. In this work, multilayer broadband and commercial porous SiO2 AR coatings have been subject to abrasion testing that simulates the regular cleaning of solar modules in the field, using Felt Pad and CS-10 abradant materials. The Felt Pad abrasion has no impact on the multilayer coating, but caused visible damage to the porous SiO2, increasing WAR from 5.97% to 6.75% after 100 cycles. After 50 and 100 abrasion cycles of CS-10, significant scratches are visible on the porous SiO2 coating, and the weighted average reflectance (WAR) of the coating increases from 5.97% to 7.08% after 100 cycles. The coating is fully removed in some abraded areas. The multilayer AR coating also experiences some damage after CS-10 abrasion, increasing WAR from 5.84% to 6.68%. Optical microscopy and Scanning Electron Microscopy (SEM) show the nature of the abrasion damage caused. Overall, the multilayer AR coating shows significantly higher abrasion resistance than the porous SiO2. Significant abrasion damage to porous SiO2 AR coatings is a major problem for solar asset managers resulting in long-term power losses.
{"title":"Testing the Abrasion Resistance of Porous SiO2 Anti-reflection Coatings for Solar Cover Glass","authors":"A. Law, F. Bukhari, L. Jones, A. Abbas, J. Walls","doi":"10.1109/PVSC48317.2022.9938907","DOIUrl":"https://doi.org/10.1109/PVSC48317.2022.9938907","url":null,"abstract":"The cover glass sheet on solar modules can cause reflection losses as well as soiling build-up. Reflection losses can be addressed with anti-reflection (AR) coatings, whilst soiling is removed by mechanical cleaning processes that are effective but can have adverse effects on surface coatings. In this work, multilayer broadband and commercial porous SiO2 AR coatings have been subject to abrasion testing that simulates the regular cleaning of solar modules in the field, using Felt Pad and CS-10 abradant materials. The Felt Pad abrasion has no impact on the multilayer coating, but caused visible damage to the porous SiO2, increasing WAR from 5.97% to 6.75% after 100 cycles. After 50 and 100 abrasion cycles of CS-10, significant scratches are visible on the porous SiO2 coating, and the weighted average reflectance (WAR) of the coating increases from 5.97% to 7.08% after 100 cycles. The coating is fully removed in some abraded areas. The multilayer AR coating also experiences some damage after CS-10 abrasion, increasing WAR from 5.84% to 6.68%. Optical microscopy and Scanning Electron Microscopy (SEM) show the nature of the abrasion damage caused. Overall, the multilayer AR coating shows significantly higher abrasion resistance than the porous SiO2. Significant abrasion damage to porous SiO2 AR coatings is a major problem for solar asset managers resulting in long-term power losses.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121229301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/PVSC48317.2022.9938759
Jing Huang, R. Perez, J. Schlemmer, Marc J. R. Perez, A. Bhat, P. Keelin, A. Kubiniec
Satellite-derived solar irradiance data are known to underestimate temporal variability compared to point measurements because of their pixel-averaging nature. In this study, we apply an algorithm imposing random noise to enhance the temporal variability of 5-minute satellite-derived solar irradiance data. We show that the resulting product, termed as True Dynamics, has clear-sky exceedance events and the frequency of large ramp events closer to observation. In addition, the increase of temporal resolution of irradiance data significantly reduces the underestimation error of power inverter clipping under high DC:AC capacity ratios conditions.
{"title":"Enhancing temporal variability of 5-minute satellite-derived solar irradiance data","authors":"Jing Huang, R. Perez, J. Schlemmer, Marc J. R. Perez, A. Bhat, P. Keelin, A. Kubiniec","doi":"10.1109/PVSC48317.2022.9938759","DOIUrl":"https://doi.org/10.1109/PVSC48317.2022.9938759","url":null,"abstract":"Satellite-derived solar irradiance data are known to underestimate temporal variability compared to point measurements because of their pixel-averaging nature. In this study, we apply an algorithm imposing random noise to enhance the temporal variability of 5-minute satellite-derived solar irradiance data. We show that the resulting product, termed as True Dynamics, has clear-sky exceedance events and the frequency of large ramp events closer to observation. In addition, the increase of temporal resolution of irradiance data significantly reduces the underestimation error of power inverter clipping under high DC:AC capacity ratios conditions.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127501714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/pvsc48317.2022.9938563
I. Lam, Austin G. Kuba, Nathan J. Rollins, W. Shafarman
Capacitance measurement techniques are powerful methods for characterizing semiconductor devices. Voltage dependent admittance spectroscopy (C-V-f) has recently been used to characterize electronic loss mechanisms in CIGS solar cells. In this work, drift-diffusion simulations of devices are used to create a large dataset of C- V -f loss map images that provide a fingerprint for the electronic loss mechanisms of a solar cell. Analytic extraction of electronic properties from these loss maps is difficult, so a machine learning method for characterizing measured C- V -f profiles of real devices is developed to identify dominant loss mechanisms. The method is demonstrated with a perovskite solar cell. Various properties are simulated including contact work functions, doping concentrations, series resistance, bulk defect concentrations, and interface defect concentrations. To reduce computational complexity, the simulations focus primarily on MAPI bulk defects and C60/MAPI/CuPC interface defects. Principal component analysis is used to verify that different features observed in the loss maps can be represented independently of each other. Although the simulated data appears to be a good candidate for modelling, there could be issues reconciling simulated and experimental data due to factors such as experimental noise, variation in measurement intensity, and contributions not accounted for in the simulation such as perovskite ion migration.
电容测量技术是表征半导体器件的有力方法。电压相关导纳光谱(C-V-f)最近被用来表征CIGS太阳能电池的电子损失机制。在这项工作中，器件的漂移扩散模拟用于创建C- V -f损耗图图像的大型数据集，为太阳能电池的电子损耗机制提供指纹。从这些损耗图中分析提取电子特性是困难的，因此开发了一种机器学习方法来表征实际器件的测量C- V -f分布，以识别主要的损耗机制。用钙钛矿太阳能电池验证了该方法。模拟了各种特性，包括接触功函数、掺杂浓度、串联电阻、体缺陷浓度和界面缺陷浓度。为了降低计算复杂度，模拟主要集中在MAPI本体缺陷和C60/MAPI/CuPC接口缺陷上。主成分分析用于验证在损失图中观察到的不同特征可以相互独立地表示。虽然模拟数据似乎是一个很好的建模候选者，但由于实验噪声，测量强度的变化以及模拟中未考虑的贡献(如钙钛矿离子迁移)等因素，可能存在协调模拟和实验数据的问题。
{"title":"Predicting solar cell recombination from C-V-f fingerprints using machine learning","authors":"I. Lam, Austin G. Kuba, Nathan J. Rollins, W. Shafarman","doi":"10.1109/pvsc48317.2022.9938563","DOIUrl":"https://doi.org/10.1109/pvsc48317.2022.9938563","url":null,"abstract":"Capacitance measurement techniques are powerful methods for characterizing semiconductor devices. Voltage dependent admittance spectroscopy (C-V-f) has recently been used to characterize electronic loss mechanisms in CIGS solar cells. In this work, drift-diffusion simulations of devices are used to create a large dataset of C- V -f loss map images that provide a fingerprint for the electronic loss mechanisms of a solar cell. Analytic extraction of electronic properties from these loss maps is difficult, so a machine learning method for characterizing measured C- V -f profiles of real devices is developed to identify dominant loss mechanisms. The method is demonstrated with a perovskite solar cell. Various properties are simulated including contact work functions, doping concentrations, series resistance, bulk defect concentrations, and interface defect concentrations. To reduce computational complexity, the simulations focus primarily on MAPI bulk defects and C60/MAPI/CuPC interface defects. Principal component analysis is used to verify that different features observed in the loss maps can be represented independently of each other. Although the simulated data appears to be a good candidate for modelling, there could be issues reconciling simulated and experimental data due to factors such as experimental noise, variation in measurement intensity, and contributions not accounted for in the simulation such as perovskite ion migration.","PeriodicalId":435386,"journal":{"name":"2022 IEEE 49th Photovoltaics Specialists Conference (PVSC)","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123197602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-05DOI: 10.1109/PVSC48317.2022.9938517
G. M. N. Javier, P. Dwivedi, Yoann Buratti, T. Trupke, Z. Hameiri
Extracting solar cell electrical parameters directly from luminescence images, instead of the common current-voltage (I-V) measurements, can significantly increase the throughput and reduce the operation cost of photovoltaic production lines. This study investigates the capability of obtaining the fill factor (FF) from luminescence images by assessing the accuracy of published empirical expressions for the FF. The fitting approach for empirical coefficients was first modified. The resulting coefficients marginally improved the fit for the electrical range suggested in the literature as well as of current state-of-the-art solar cells. Nevertheless, through a dataset of 15,000 I-V measurements of industrial cells, a gap between the predicted and measured FF was observed. The impact of the effective ideality factor, edge recombination, and non-uniform recombination on the estimated FF were therefore investigated. Results show that adding information on the ideality factor or edge recombination increases the prediction accuracy. Moreover, the expressions tend to overestimate the FF for non-uniform cells. This study provides insights on the accurate estimation of FF through metrics that can be captured from luminescence images. This paves the way to improving the analysis of luminescence images for end-of-line characterization in industrial manufacturing lines.
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