A simulation study on the impact of band gap profile variations and secondary barriers on the temperature behavior, performance ratio, and energy yield of Cu(In,Ga)(Se,S)2solar cells

2014 ◽  
Vol 212 (2) ◽  
pp. 336-347 ◽  
Author(s):  
Christian Schubbert ◽  
Patrick Eraerds ◽  
Michael Richter ◽  
Jürgen Parisi ◽  
Ingo Riedel ◽  
...  
Keyword(s):  
Band Gap ◽  
Simulation Study ◽  
Temperature Behavior ◽  
Performance Ratio ◽  
Energy Yield ◽  
The Impact

scholarly journals A New Model for Estimation of Energy Extraction from Bifacial Photovoltaic Modules

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5089
Author(s):  
Preeti Kumari Sahu ◽  
J. N. Roy ◽  
Chandan Chakraborty ◽  
Senthilarasu Sundaram
Keyword(s):  
Tilt Angle ◽  
Geographical Location ◽  
Performance Ratio ◽  
Real Field ◽  
Photovoltaic Module ◽  
Rear Side ◽  
Energy Yield ◽  
Solar Photovoltaic ◽  
The Cost ◽  
The Impact

The energy yield from bifacial solar photovoltaic (PV) systems can be enhanced by optimizing the tilt angle. Bifacial modules boost the energy yield by 4% to 15% depending on the module type and ground reflectivity with an average of 9%. The selection of tilt angle depends on several factors, including the geographical location, weather variation, etc. Compared to the variable tilt angle, a constant angle is preferred from the point of view of the cost of installation and the cost of maintenance. This paper proposes a new method for analysing bifacial modules. A simpler rear-side irradiance model is presented to estimate the energy yield of a bifacial solar photovoltaic module. The detailed analysis also explores the optimum tilt angle for the inclined south–north orientation to obtain the maximum possible yield from the module. Taking four regions into account, i.e., Kharagpur, Ahmedabad, Delhi, and Thiruvananthapuram, in the Indian climate, we studied several cases. The Kharagpur system showed a monthly rear irradiance gain of 13%, and the Delhi climate showed an average performance ratio of 19.5%. We studied the impact of albedo and GCR on the tilt angle. Finally, the estimated model was validated with the PVSyst version 6.7.6 as well as real field test measurements taken from the National Renewable Energy Laboratory (NREL) located in the USA.

scholarly journals Assessment of Pellets from Three Forest Species: From Raw Material to End Use

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 447
Author(s):  
Miguel Alfonso Quiñones-Reveles ◽  
Víctor Manuel Ruiz-García ◽  
Sarai Ramos-Vargas ◽  
Benedicto Vargas-Larreta ◽  
Omar Masera-Cerutti ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Ash Content ◽  
Hot Water ◽  
Raw Material ◽  
Chemical Components ◽  
Energy Yield ◽  
Cellulose Content ◽  
Fixed Carbon ◽  
End Use ◽  
The Impact

This study aimed to evaluate and compare the relationship between chemical properties, energy efficiency, and emissions of wood and pellets from madroño Arbutus xalapensis Kunth, tázcate Juniperus deppeana Steud, and encino colorado Quercus sideroxyla Humb. & Bonpl. in two gasifiers (top-lit-up-draft (T-LUD) and electricity generation wood camp stove (EGWCS)) in order to determine the reduction of footprint carbon. In accordance with conventional methodologies, we determined the extracts and chemical components (lignin, cellulose, holocellulose), and the immediate analyses were carried out (volatile materials, fixed carbon, ash content and microanalysis of said ash), as well as the evaluation of emission factors (total suspended particulate matter (PM2.5), CO, CO2, CH4, black carbon (BC), elemental carbon (EC), and organic carbon (OC)). The results were statistically analyzed to compare each variable among species and gasifiers. The raw material analyzed showed how the pH ranged from 5.01 to 5.57, and the ash content ranged between 0.39 and 0.53%. The content values of Cu, Zn, Fe, Mg, and Ca ranged from 0.08 to 0.22, 0.18 to 0.19, 0.38 to 0.84, 1.75 to 1.90, and 3.62 to 3.74 mg kg−1, respectively. The extractive ranges from cyclohexane were 2.48–4.79%, acetone 2.42–4.08%, methanol 3.17–7.99%, and hot water 2.12–4.83%. The range of lignin was 18.08–28.60%. The cellulose content ranged from 43.30 to 53.90%, and holocellulose from 53.50 to 64.02%. The volatile material range was 81.2–87.42%, while fixed carbon was 11.30–17.48%; the higher heating value (HHV) of raw material and pellets presented the ranges 17.68–20.21 and 19.72–21.81 MJ kg−1, respectively. Thermal efficiency showed statistically significant differences (p < 0.05) between pellets and gasifiers, with an average of 31% Tier 3 in ISO (International Organization for Standardization) for the T-LUD and 14% (ISO Tier 1) for EGWCS, with Arbutus xalapensis being the species with the highest energy yield. The use of improved combustion devices, as well as that of selected raw material species, can reduce the impact of global warming by up to 33% on a cooking task compared to the three-stone burner.

scholarly journals The impact of excluding or including Death Certificate Initiated (DCI) cases on estimated cancer survival: A simulation study

2021 ◽  
Vol 71 ◽  
pp. 101881
Author(s):  
Therese M.-L. Andersson ◽  
Tor Åge Myklebust ◽  
Mark J. Rutherford ◽  
Bjørn Møller ◽  
Isabelle Soerjomataram ◽  
...  
Keyword(s):  
Simulation Study ◽  
Cancer Survival ◽  
Death Certificate ◽  
The Impact

scholarly journals When does the use of individual patient data in network meta-analysis make a difference? A simulation study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Steve Kanters ◽  
Mohammad Ehsanul Karim ◽  
Kristian Thorlund ◽  
Aslam Anis ◽  
Nick Bansback
Keyword(s):  
Simulation Study ◽  
Treatment Effect ◽  
Mean Squared Error ◽  
Individual Patient Data ◽  
Meta Analysis ◽  
Model Performance ◽  
Patient Data ◽  
Meta Regression ◽  
Treatment Comparisons ◽  
The Impact

Abstract Background The use of individual patient data (IPD) in network meta-analyses (NMA) is rapidly growing. This study aimed to determine, through simulations, the impact of select factors on the validity and precision of NMA estimates when combining IPD and aggregate data (AgD) relative to using AgD only. Methods Three analysis strategies were compared via simulations: 1) AgD NMA without adjustments (AgD-NMA); 2) AgD NMA with meta-regression (AgD-NMA-MR); and 3) IPD-AgD NMA with meta-regression (IPD-NMA). We compared 108 parameter permutations: number of network nodes (3, 5 or 10); proportion of treatment comparisons informed by IPD (low, medium or high); equal size trials (2-armed with 200 patients per arm) or larger IPD trials (500 patients per arm); sparse or well-populated networks; and type of effect-modification (none, constant across treatment comparisons, or exchangeable). Data were generated over 200 simulations for each combination of parameters, each using linear regression with Normal distributions. To assess model performance and estimate validity, the mean squared error (MSE) and bias of treatment-effect and covariate estimates were collected. Standard errors (SE) and percentiles were used to compare estimate precision. Results Overall, IPD-NMA performed best in terms of validity and precision. The median MSE was lower in the IPD-NMA in 88 of 108 scenarios (similar results otherwise). On average, the IPD-NMA median MSE was 0.54 times the median using AgD-NMA-MR. Similarly, the SEs of the IPD-NMA treatment-effect estimates were 1/5 the size of AgD-NMA-MR SEs. The magnitude of superior validity and precision of using IPD-NMA varied across scenarios and was associated with the amount of IPD. Using IPD in small or sparse networks consistently led to improved validity and precision; however, in large/dense networks IPD tended to have negligible impact if too few IPD were included. Similar results also apply to the meta-regression coefficient estimates. Conclusions Our simulation study suggests that the use of IPD in NMA will considerably improve the validity and precision of estimates of treatment effect and regression coefficients in the most NMA IPD data-scenarios. However, IPD may not add meaningful validity and precision to NMAs of large and dense treatment networks when negligible IPD are used.

Molecular Dynamics Study on the Impact of the Cutting Depth to the Titanium Nanometric Cutting

2014 ◽  
Vol 536-537 ◽  
pp. 1431-1434 ◽  
Author(s):  
Ying Zhu ◽  
Yin Cheng Zhang ◽  
Shun He Qi ◽  
Zhi Xiang
Keyword(s):  
Molecular Dynamics ◽  
Potential Energy ◽  
Cutting Force ◽  
Simulation Study ◽  
Cutting Process ◽  
Work Piece ◽  
Cutting Depth ◽  
Nanometric Cutting ◽  
The Impact

Based on the molecular dynamics (MD) theory, in this article, we made a simulation study on titanium nanometric cutting process at different cutting depths, and analyzed the changes of the cutting depth to the effects on the work piece morphology, system potential energy, cutting force and work piece temperature in this titanium nanometric cutting process. The results show that with the increase of the cutting depth, system potential energy, cutting force and work piece temperature will increase correspondingly while the surface quality of machined work piece will decrease.

scholarly journals A study on the reliability and performance of solar powered street lighting systems

2017 ◽  
Vol 5 (2) ◽  
pp. 110 ◽  
Author(s):  
Adebayo Fashina ◽  
Salifu Azeko ◽  
Joseph Asare ◽  
Chukwuemeka Ani ◽  
Vitalis Anye ◽  
...  
Keyword(s):  
Performance Indicators ◽  
Performance Ratio ◽  
Energy Yield ◽  
Street Lighting ◽  
Technical Performance ◽  
Humid Environment ◽  
Total Failure ◽  
Lighting Systems ◽  
And Performance ◽  
Solar Powered

This paper presents the results of a study on the reliability and performance of the solar-powered street lighting systems installed at the African University of Science and Technology (AUST) in Nigeria, a hot and humid environment. The technical performance of the systems was studied using the following performance indicators: system energy yield, capture loss, as well as the system performance ratio while the reliability of the systems was examined using a model developed from the findings from the maintenance and fault diagnosis of the systems. The model was used to predict the total failure and survival probability of the systems using the Weibull distribution. The performance evaluation during the monitored period (February 2012 to January 2015) indicated that the performance ratios of the systems vary from 70% to 89% and the energy yields of the systems ranging from 2.87 h/day to 5.57 h/day. The results from the reliability analysis also showed that when the stress concentration factor around the notch between the cable terminals in the charge controller increases, the charge controller will become overheated, which in turn affected other components of the systems. The implications of this study are also discussed for the design and development of future solar-powered street lighting systems.

scholarly journals Performance analysis of photovoltaic plants installed in dairy cattle farms

2015 ◽  
Vol 46 (2) ◽  
pp. 62
Author(s):  
Remo Alessio Malagnino
Keyword(s):  
Energy Efficiency ◽  
Performance Analysis ◽  
Dairy Cattle ◽  
Geographical Information ◽  
Research Centre ◽  
Energy Yield ◽  
Pv System ◽  
Technical Parameters ◽  
Global Efficiency ◽  
The Impact

Electric production from renewable resources, such as solar photovoltaic (PV), is playing an increasingly essential role in the agricultural industry because of the progressive increase in the energy price from fossil fuels and the simultaneous decrease in the income deriving from farming activities. A central issue in the sustainable diffusion of PV technologies is represented by the actual energy efficiency of a PV system. For these reasons, a performance analysis has been carried out in order to assess the potentials offered by different PV plants within a defined geographical context with the aim of investigating the impact of each component has on the PV generator global efficiency and defining the main technical parameters that allow to maximise the annual specific electric energy yield of an architectonically integrated plant, installed in a dairy house, compared to a ground-mounted plant. The annual performances of three grid connected PV plants installed in the same dairy cattle farm have been analysed: two are architectonically integrated plants - <em>i.e.</em>, a rooftop unidirectional and a multi-field systems (both 99 kW<sub>p</sub>) - and the other is a ground-mounted plant (480 kW<sub>p</sub>). Furthermore, the electrical performances, estimated by the photovoltaic geographical information system (PVGIS), developed by the EU Joint Research Centre, and by an analytical estimation procedure (AEP), developed on the basis of a meteo-climatic database related to the records of the nearest weather station and integrated by the components’ technical specifications, have been compared with the actual yields. The best annual performance has been given by the ground-mounted PV system, with an actual increase of 26% and in the range of 6÷12% according to different estimations, compared to the integrated systems, which were globally less efficient (average total loss of 26÷27% compared to 24% of the ground-mounted system). The AEP and PVGIS software estimates showed a good level of reliability for mean deviations between the annual actual and estimated electrical power yields have been equal to 11.5% for each PV system given the actual irradiation’ s uncertainty during the examined year. The main technical parameters, crucial to maximise the energy yield from a ground-mounted PV system to an integrated one, have been identified in the Tilt and Azimuth angles. Indeed, once a variance of 3÷4% in the global efficiency has been confirmed when the type of PV system is changed, in the case of the unidirectional integrated PV plant, the high roof pitch and the almost South orientation guarantee a solar energy increase up to 18% higher than that obtainable on the horizontal plane and similar to the increase estimated for the ground-mounted generator (+20%). Hence, integrated PV systems, besides reaching the same levels of energy efficiency as those ground-mounted, are also more <em>sustainable</em> than the latter. This is true providing that there are both a suitable orientation and an accurate design, especially to prevent the PV panels’ warming during summer, on an already available surface that is, however, functional to the roof’s architecture.

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