Performance Evaluation of Two Photovoltaic Cell Technologies in Fluctuating Weather Conditions, Using EN50530 Test Procedure

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
L. Premalatha ◽  
Nasrudin Abd Rahim ◽  
Mohamad Fathi
Keyword(s):  
Crystalline Silicon ◽  
Test Procedure ◽  
Technical Information ◽  
Weather Conditions ◽  
Photovoltaic Cell ◽  
Standard Test ◽  
Energy Yield ◽  
Study Test ◽  
Fluctuating Irradiance ◽  
Selection Of

Generally, photovoltaic (PV) cell manufacturers provide technical information, at standard test conditions (STCs) and nominal operating cell temperature (NOCT) ratings. However, this information is not sufficient to accurately predict the module operations under dynamic weather. In this study, test is conducted under fluctuating irradiance conditions, provided by EN50530 test procedure, to evaluate the performance of multi crystalline silicon and thin-film PV cells. Particular attention is given to the influence that the level and the slope of irradiance change have on the energy yield of PV technologies. This analysis aimed at revealing the appropriate selection of PV technology for obtaining maximum power under dynamic weather conditions.

scholarly journals Variable Parameters for a Single Exponential Model of Photovoltaic Modules in Crystalline-Silicon

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2138 ◽  
Author(s):  
Ali Murtaza ◽  
Umer Munir ◽  
Marcello Chiaberge ◽  
Paolo Di Leo ◽  
Filippo Spertino
Keyword(s):  
Crystalline Silicon ◽  
Weather Condition ◽  
Computation Time ◽  
Weather Conditions ◽  
Iterative Solution ◽  
Exponential Model ◽  
Standard Test ◽  
Photovoltaic Module ◽  
Proposed Model ◽  
Power Point

The correct approximation of parallel resistance (Rp) and series resistance (Rs) poses a major challenge for the single diode model of the photovoltaic module (PV). The bottleneck behind the limited accuracy of the model is the static estimation of resistive parameters. This means that Rp and Rs, once estimated, usually remain constant for the entire operating range of the same weather condition, as well as for other conditions. Another contributing factor is the availability of only standard test condition (STC) data in the manufacturer’s datasheet. This paper proposes a single-diode model with dynamic relations of Rp and Rs. The relations not only vary the resistive parameters for constant/distinct weather conditions but also provide a non-iterative solution. Initially, appropriate software is used to extract the data of current-voltage (I-V) curves from the manufacturer’s datasheet. By using these raw data and simple statistical concepts, the relations for Rp and Rs are designed. Finally, it is proved through root mean square error (RMSE) analysis that the proposed model holds a one-tenth advantage over numerous recently proposed models. Simultaneously, it is low complex, iteration-free (0 to voltage in maximum power point Vmpp range), and requires less computation time to trace the I-V curve.

Optimizing genotype-environment-management interactions to ensure silage maize production in the Chinese Maize Belt

2020 ◽  
Vol 80 (2) ◽  
pp. 133-146
Author(s):  
L Zhang ◽  
Z Zhang ◽  
J Cao ◽  
Y Luo ◽  
Z Li
Keyword(s):  
Field Experiments ◽  
Weather Conditions ◽  
Growth Cycle ◽  
High Energy ◽  
Risk Level ◽  
Energy Yield ◽  
Maize Production ◽  
Early Date ◽  
Environment Management ◽  
Silage Maize

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.

Assessment of reproductive capacity of representatives of ancestral complexes and especially their selection of seed in dry conditions

2019 ◽  
pp. 1-23
Author(s):  
А.В. Семенютина ◽  
С.Е. Лазарев ◽  
К.А. Мельник
Keyword(s):  
Weather Conditions ◽  
Reproductive Capacity ◽  
Limiting Factors ◽  
Scientific Center ◽  
Gleditsia Triacanthos ◽  
Biological Potential ◽  
Forest Reclamation ◽  
Dry Conditions ◽  
Generative Phase ◽  
Selection Of

Представители родовых комплексов Robinia (Робиния), Gleditsia (Гледичия) относятся к экономически важным и перспективным, для деградированных ландшафтов засушливого региона, видам растений. Несмотря на это до последнего времени отсутствуют сведения по многим видам этих родовых комплексов, связанные с вопросами экологических основ семеноведения и их репродуктивной способности в условиях светлокаштановых почв Волгоградской области. Все это направлено на выявление и расширение перспективных ареалов культивирования для лесомелиорации и озеленения населенных пунктов. Цель исследований изучение репродуктивной способности представителей родовых комплексов Robinia (Робиния), Gleditsia (Гледичия) в коллекциях ФНЦ агроэкологии РАН и выявление особенностей их селекционного семеноведения для лесомелиорации и озеленения населенных пунктов в сухостепных условиях. Объектами исследований являлись виды и формы рода Robinia: R. viscosa Vent. R. neomexicana Gray. R. pseudoacacia L. R. neomexicana х pseudoacacia, и Gleditsia (G. triacanthos L., G. triacanthos L. f. inermis, G. caspica Desf, G. texana Sarg., G. aquatica, G. japonica, G. caspica, G. sinensis), произрастающие в кластерных участках коллекций ФНЦ агроэкологии РАН, кадастр 34:34:000000:122, 34:34:060061:10. Разработка основ селекционного семеноведения базируется на изучении репродуктивных особенностей выделенных для целевого использования собственных биоресурсов с учетом возможностей всестороннего изучения генеративных качеств и оценки биологического потенциала. Выявлено, что стабильность плодоношения фиксируется через несколько лет после вступления в генеративную фазу: у Robinia и Gleditsia 67 лет. Первое цветение у Gleditsia triacanthos и G. texana, G. aquatica наблюдалось в возрасте 5 лет, G. japonica 6, G. caspica и G. sinensis 8 лет. Завязываемость плодов зависит не только от возраста растения, но и от погодных условий во время цветения. На семенную продуктивность влияет количество выпавших осадков и сумма активных температур в период созревания плодов. Формирование более крупных плодов и семян наблюдается в возрасте до 15 лет. В результате исследований (20172019 гг.) выявлено влияние лимитирующих факторов на биологический потенциал цветения, плодоношения и семенную продуктивность для определения ареалов их культивирования. Representatives of generic systems Robinia, Gleditsia are economically important and promising for degraded arid landscapes of the region, types of plants. Despite this, until recently, there is no information on many types of these generic complexes related to the environmental foundations of seed and their reproductive capacity in light chestnut soils of the Volgograd region. All this is aimed at identifying and expanding promising areas of cultivation for forest reclamation and greening of settlements. The aim of the research is to study the reproductive capacity of representatives of ancestral complexes Robinia, Gleditsia in the collections of the Federal scientific center for Agroecology Russian Academy of Sciences and the identifying features of their selection of seed for forest reclamation and landscaping of settlements in the dry steppe conditions. The objects of research were species and forms of the genus Robinia: R. viscosa Vent. R. neomexicana Gray. R. pseudoacacia L. R. neomexicana x pseudoacacia and Gleditsia (G. triacanthos L., G. triacanthos L. f. inermis, G. caspica Desf, G. texana Sarg., G. aquatica, G. japonica, G. caspica, G. sinensis), growing in the cluster areas of collections of FSC Agroecology RAS, cadastre 34:34:000000:122, 34:34:060061:10. The development of the principles of seed breeding is based on the study of reproductive characteristics of the allocated for the targeted use of their own bioresources, taking into account the possibilities of a comprehensive study of generative qualities and assessment of biological potential. It was found that the stability of fruiting is fixed a few years after entering the generative phase: Robinia and Gleditsia 67 years. The first flowering in Gleditsia triacanthos and G. texana, G. aquatica was observed at the age of 5 years, G. japonica 6, G. caspica and G. sinensis 8 years. Fruit setability depends not only on the age of the plant, but also on weather conditions during flowering. Seed productivity is affected by the amount of precipitation and the amount of active temperatures during the ripening period. The formation of larger fruits and seeds is observed in the age of 15 years. As a result of studies (20172019), the influence of limiting factors on the biological potential of flowering, fruiting and seed production to determine the areas of their cultivation was revealed.

scholarly journals Development of Thermal Performance Metrics for Direct Gas-Fired Circulating Heaters

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 588
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff
Keyword(s):  
Mass Flow ◽  
Measurement System ◽  
Thermal Efficiency ◽  
Performance Metrics ◽  
Standardized Test ◽  
Flow System ◽  
Standard Test ◽  
Testing System ◽  
Measurement Systems ◽  
Selection Of

Many climate-controlled agricultural buildings use direct gas-fired circulating heaters (DGFCH) for supplement heat. There is no standardized test to calculate thermal efficiency for these heaters. This study aimed to develop a measurement system and analytical analysis for thermal efficiency, quantify the measurement uncertainty, and assess economics of DGFCH efficiency. The measurement system developed was similar to the ASHRAE 103 standard test stand with adaptations to connect the apparatus to the DGFCH. Two different propane measurement systems were used: input ratings < 30 kW used a mass flow system and input ratings > 30 kW used a volumetric gas meter. Three DGFCHs (21.9, 29.3, 73.3 kW) were tested to evaluate the system. Thermal efficiencies ranged from 92.4% to 100.9%. The resulting uncertainty (coverage factor of 2; ~95% Confidence Interval) ranged from 13.1% to 30.7% for input ratings of 56.3 to 11.4 kW. Key sources of uncertainty were propane and mass flow of air measurement. The economic impact of 1% difference in thermal efficiency ranged from USD $61.3 to $72.0 per heating season. Refinement of the testing system and procedures are needed to reduce the uncertainty. The application of this system will aid building designers in selection of DGFCHs for various applications.

scholarly journals Analysis of Power Generation for Solar Photovoltaic Module with Various Internal Cell Spacing

2021 ◽  
Vol 13 (11) ◽  
pp. 6364
Author(s):  
June Raymond L. Mariano ◽  
Yun-Chuan Lin ◽  
Mingyu Liao ◽  
Herchang Ay
Keyword(s):  
Power Output ◽  
Spacing Effect ◽  
Photovoltaic Cell ◽  
Standard Test ◽  
Photovoltaic Module ◽  
Solar Pv ◽  
Engineering Software ◽  
Internal Cell ◽  
Cell Spacing ◽  
Pv Module

Photovoltaic (PV) systems directly convert solar energy into electricity and researchers are taking into consideration the design of photovoltaic cell interconnections to form a photovoltaic module that maximizes solar irradiance. The purpose of this study is to evaluate the cell spacing effect of light diffusion on output power. In this work, the light absorption of solar PV cells in a module with three different cell spacings was studied. An optical engineering software program was used to analyze the reflecting light on the backsheet of the solar PV module towards the solar cell with varied internal cell spacing of 2 mm, 5 mm, and 8 mm. Then, assessments were performed under standard test conditions to investigate the power output of the PV modules. The results of the study show that the module with an internal cell spacing of 8 mm generated more power than 5 mm and 2 mm. Conversely, internal cell spacing from 2 mm to 5 mm revealed a greater increase of power output on the solar PV module compared to 5 mm to 8 mm. Furthermore, based on the simulation and experiment, internal cell spacing variation showed that the power output of a solar PV module can increase its potential to produce more power from the diffuse reflectance of light.

scholarly journals GEI. Greek Economic Inscriptions (online)

Axon ◽  
2019 ◽  
Author(s):  
Donatella Erdas ◽  
Anna Magnetto
Keyword(s):  
Detailed Analysis ◽  
English Translation ◽  
Technical Information ◽  
Ancient Greece ◽  
Economic Life ◽  
Ancient Greek ◽  
Critical Editions ◽  
Greek Economy ◽  
Selection Of

In recent years the attention of modern scholars to ancient Greek economy has received impetus from a series of newly published documents of undisputed significance. The results have been a deeply renewed examination of consolidated theoretical positions, and a detailed analysis of specific aspects of the economic life of the polis. Within this framework the GEI project aims at providing an online collection of epigraphic documents related to the economy of ancient Greece. Some of these documents, already known or newly discovered, have never been collected in a selection of this kind. The project covers a period from the archaic age to 1st century BC. The selected texts are representative of the different areas of ancient Greek economy, and are marked-up using the EpiDoc encoding conventions. For each document all technical information has been provided along with existing critical editions, bibliography, a critical apparatus, an English translation and a commentary.

scholarly journals A Study on Factors Influencing the Determination of Moisture Content of Fibrous Peat

2011 ◽  
Vol 2 (2) ◽  
pp. 39-47 ◽  
Author(s):  
Pui Tau Shien ◽  
Seneviratne H.N. ◽  
Dygku Salma Awg Ismail
Keyword(s):  
Moisture Content ◽  
Particle Density ◽  
Peat Soil ◽  
Test Procedure ◽  
Field Measurements ◽  
Standard Test ◽  
Moisture Loss ◽  
Fibrous Peat ◽  
Saturated Sample

Fibrous peat is an undrained peat that usually possesses very high moisture content. However, not all experimental procedures are applicable for determination of moisture content of fibrous peat. This research is aimed at examining the determination of insitu moisture content of fibrous peat using field measurements. The peat soil samples were collected at shallow depths from Asajaya at Kota Samarahan and Taman Kopodims at Matang , Kuching Sarawak by using peat auger. The laboratory tests such as determination of moisture content, fiber content, particle density and ash content were conducted on the collected samples in order to establish relationships between the parameters. Undisturbed peat samples from Matang were subjected to falling head permeability test to determine the saturated permeability. The saturated sample were then allowed to drain freely to simulate the moisture loss possible during sampling when samples were brought out of boreholes. The test results showed that moisture content varies according to the drying temperature and position of the soil sample (top, middle and bottom) during sampling. Comparing samples from both locations, peat soil from Kota Samarahan possessed higher moisture content. The saturated permeability of peat sample was in the range of 2.62 – 3.05 cm/s. The free draining trial showed that moisture loss during sampling significantly influence the moisture content measurement. The variation in value of moisture content for fibrous peat may occurs due to several factors such as existing ground water table, sampling method by boring, existing standard test procedure which is not suitable for peat soils requirement and also because of the physical properties which varied according to depth of soil.

scholarly journals KENYAMANAN IKLIM LOKASI WISATA BERBASIS ALAM DI KAWASAN TROPIS

Agromet ◽  
2019 ◽  
Vol 33 (2) ◽  
pp. 53-61
Author(s):  
Nofi Yendri Sudiar
Keyword(s):  
Weather Conditions ◽  
Education Level ◽  
Tourism Industry ◽  
Botanical Gardens ◽  
Visitor Perceptions ◽  
Survey Results ◽  
Climate Comfort ◽  
Selection Of

This research reveals visitors perceptions of climate comfort in nature-based tourism areas in Ecopark Ancol, Bogor Botanical Gardens (KRB) and Cibodas Botanical Gardens (KRC). In addition to calculating the comfort score using the TCI and HCI methods and modifying their thermal aspects, a survey was also carried out in all three tourism areas simultaneously. The survey was conducted to collect data on climate comfort perceptions and the role of the weather on these comfort. A total of 793 respondents participated in this study. The majority of visitors stated that the weather affected the comfort of the climate during the tour. But weather conditions do not fully influence decisions in the selection of tourist visits. The level of perceived climate comfort for the three tourism sites namely Ecopark was perceived as neutral (57.3%), KRB was perceived as comfortable (60%) and KRC was perceived as comfortable (78.4%). While based on the score calculation approaching the survey results in Ecopark is TCI index modified in its thermal aspect with PET Tianjin (57.2). KRB is HCI without modification (59) and KRC is HCI modified by its thermal aspect with PET Tianjin (77.6). Statistically there are significant differences between sex, age, education level and topography. By understanding visitor perceptions, strategies and appropriate actions can be developed to increase comfort in the nature-based tourism industry.

scholarly journals An investigation of human vs. technology-induced variation in catchability for a selection of European fishing fleets

2011 ◽  
Vol 68 (10) ◽  
pp. 2252-2263 ◽  
Author(s):  
Stéphanie Mahévas ◽  
Youen Vermard ◽  
Trevor Hutton ◽  
Ane Iriondo ◽  
Angélique Jadaud ◽  
...  
Keyword(s):  
Linear Models ◽  
Generalized Additive Models ◽  
Technical Information ◽  
Fishing Effort ◽  
Additive Models ◽  
Induced Variation ◽  
Fishing Fleets ◽  
The Impact ◽  
Selection Of ◽  
Experience Effect

Abstract Mahévas, S., Vermard, Y., Hutton, T., Iriondo, A., Jadaud, A., Maravelias, C. D., Punzón, A., Sacchi, J., Tidd, A., Tsitsika, E., Marchal, P., Goascoz, N., Mortreux, S., and Roos, D. 2011. An investigation of human vs. technology-induced variation in catchability for a selection of European fishing fleets. – ICES Journal of Marine Science, 68: 2252–2263. The impact of the fishing effort exerted by a vessel on a population depends on catchability, which depends on population accessibility and fishing power. The work investigated whether the variation in fishing power could be the result of the technical characteristics of a vessel and/or its gear or whether it is a reflection of inter-vessel differences not accounted for by the technical attributes. These inter-vessel differences could be indicative of a skipper/crew experience effect. To improve understanding of the relationships, landings per unit effort (lpue) from logbooks and technical information on vessels and gears (collected during interviews) were used to identify variables that explained variations in fishing power. The analysis was undertaken by applying a combination of generalized additive models and generalized linear models to data from several European fleets. The study highlights the fact that taking into account information that is not routinely collected, e.g. length of headline, weight of otter boards, or type of groundrope, will significantly improve the modelled relationships between lpue and the variables that measure relative fishing power. The magnitude of the skipper/crew experience effect was weaker than the technical effect of the vessel and/or its gear.

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