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Artigos de revistas sobre o assunto "Capacity factor (CF)"
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Jung, Christopher, e Dirk Schindler. "Reasons for the Recent Onshore Wind Capacity Factor Increase". Energies 16, n.º 14 (14 de julho de 2023): 5390. http://dx.doi.org/10.3390/en16145390.
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Increasing wind capacity and capacity factors (CF) are essential for achieving the goals set by the Paris Climate Agreement. From 2010–2012 to 2018–2020, the 3-year mean CF of the global onshore wind turbine fleet rose from 0.22 to 0.25. Wind turbine siting, wind turbine technology, hub height, and curtailed wind energy are well-known CF drivers. However, the extent of these drivers for CF is unknown. Thus, the goal is to quantify the shares of the four drivers in CF development in Germany as a case. Newly developed national power curves from high-resolution wind speed models and hourly energy market data are the basis for the study. We created four scenarios, each with one driver kept constant at the 2010–2012 level, in order to quantify the share of a driver for CF change between 2010–2012 and 2019–2021. The results indicated that rising hub heights increased CF by 10.4%. Improved wind turbine technology caused 7.3% higher CF. However, the absolute CF increase amounted to only 11.9%. It is because less favorable wind turbine sites and curtailment in the later period moderated the CF increase by 2.1% and 3.6%, respectively. The drivers are mainly responsible for perennial CF development. In contrast, variations in wind resource availability drive the enormous CF inter-annual variability. No multi-year wind resource change was detected.
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Albadi, MH, e EF El-Saadany. "Comparative Study on Impacts of Power Curve Model on Capacity Factor Estimation of Pitch-Regulated Turbines". Journal of Engineering Research [TJER] 9, n.º 2 (1 de dezembro de 2012): 36. http://dx.doi.org/10.24200/tjer.vol9iss2pp36-45.
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The amount of energy produced by a turbine depends on the characteristics of both wind speed at the site under investigation and the turbine's power performance curve. The capacity factor (CF) of a wind turbine is commonly used to estimate the turbine's average energy production. This paper investigates the effect of the accuracy of the power curve model on CF estimation. The study considers three CF models. The first CF model is based on a power curve model that underestimates the turbine output throughout the ascending segment of the power curve. To compensate for the aforementioned discrepancy, the Weibull parameters, c and k, which are used to describe wind profile, are calculated based on cubic mean wind speed (CMWS). The second CF model is based on the most accurate generic power curve model available in open literature. The third CF model is based on a new model of power performance curve which mimics the behavior of a typical pitch-regulated turbine curve. As the coefficients of this power curve model are based on a general estimation of the turbine output at different wind speeds, they can be further tuned to provide a more accurate fit with turbine data from a certain manufacturer.
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Perdana, Ery, Sulardjaka e Budi Warsito. "Modeling of Capacity Factor in Rembang Coal-Fired Steam Power Plant Using Regression Modelin". International Research Journal of Innovations in Engineering and Technology 08, n.º 03 (2024): 51–56. http://dx.doi.org/10.47001/irjiet/2024.804006.
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Coal-Fired Steam Power Plant (PLTU) Rembang is an important power plant in the Central Java electricity system. Like other coal-fired steam power plants, fuel cost is the most significant expense when operating the PLTU Rembang. During the 2019-2021 period, the average fuel cost was 73.88% of total costs. One of the ways to reduce fuel costs is by improving the accuracy of fuel demand planning. Fuel procurement planning is very dependent on the projected amount of electricity sales from power plant, which is largely determined by the power plant's Capacity Factor (CF). However, PLTU Rembang does not have any CF prediction modeling. This research developed and compared four prediction models: random forest regression, support vector regression, multiple polynomial regression, and multiple linear regression. Based on the comparison of validation from the four prediction model with MAPE and R-squared parameters, the multiple linear regression models is the best model, with the lowest MAPE of 7.83% and the highest R-squared of 0.8814. This multiple linear regression model can be used to predict the CF of PLTU Rembang in the future so that fuel demand planning is more accurate.
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Janon, Akraphon, Tanakorn Wongwuttanasatian, Gumphol Faikaow e Panumas Srinor. "An Investigation of the Low Performance of the First Wind Farm in Thailand: A Case of Poor Wind Turbine-Site Matching". Advanced Materials Research 724-725 (agosto de 2013): 469–75. http://dx.doi.org/10.4028/www.scientific.net/amr.724-725.469.
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This research investigates causes of the low performance of the first commercial wind farm in Thailand. The measured data suggests that this wind farm is uncompetitive. We found that this is due to poor turbine-site matching. In contrary to a traditionally held belief, the hub-height and turbine capacity are not the contributing factors. Key performance indicators are obtained for use as benchmarks in future wind farm appraisal. Then a turbine selection method is proposed to increase the capacity factor (CF) of the wind farm. CF is used as the main performance indicator, which can be compared to other wind farms. The real capacity factor (CFR) determined using measured data is 14.90%. This CFR is considerably lower than the estimated capacity factor (CFE) of 21.53%. The low CFR is due to grid instability. In addition, the CFR is lower than the CFE by a factor of 0.69. This information is valuable to investors and wind farm developers in a wind farm feasibility study. A graphical wind turbine-site matching is proposed. Wind turbine-site matching is achieved by using normalised power output plots and power density plots on a probability density graph of the wind site. This process consumes a short period of time. An improved turbine-site matching is achieved.
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Indriyono, Bonifacius Vicky, Moch Sjamsul Hidajat, Tri Esti Rahayuningtyas, Zudha Pratama, Iffah Irdinawati e Evita Citra Yustiqomah. "Expert System for Detecting Diseases of Potatoes of Granola Varieties Using Certainty Factor Method". International Journal of Artificial Intelligence & Robotics (IJAIR) 4, n.º 2 (3 de dezembro de 2022): 70–77. http://dx.doi.org/10.25139/ijair.v4i2.5312.
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The low productivity of potatoes is caused by many factors, including the very low quality of the seeds used, poor storage, climate, capital, limited farmer knowledge, and attacks by plant-disturbing organisms, especially diseases. Not only that, many farmers are still unfamiliar with the various diseases that can attack potato plants, or their knowledge about potato plant diseases is incomplete. This study aims to design and develop an expert system web-based application technology using the Certainty Factor (CF) method to detect potato disease symptoms. The CF method defines a measure of the capacity of a fact or provision to express the level of an expert's belief in a matter experienced by the concept of belief or trust and distrust or uncertainty contained in the certainty factor. The results showed that the CF method could function optimally in detecting potato plant diseases which can help farmers based on the symptoms that appear with an accuracy value of 94%.
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Million, Jeff B., e Thomas H. Yeager. "Capture of Sprinkler Irrigation Water by Container-grown Ornamental Plants". HortScience 50, n.º 3 (março de 2015): 442–46. http://dx.doi.org/10.21273/hortsci.50.3.442.
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The capacity for container-grown plants to capture sprinkler irrigation water plays a critical role in adjusting irrigation rates to deliver required amounts of water to the container substrate. The capture factor (CF) used to describe this capacity was defined as the amount of water captured with a plant relative to the amount captured without a plant. A wind-sheltered, irrigation test area was established to measure CF as affected by plant species, plant size, container size, container spacing, and sprinkler type. CF values for 11 marketable-sized, commonly grown plant species ranged from 1 to 4 with highest values exhibited by plant species with an upright, spreading growth habit. CF values increased as plant size increased. Close container spacings (less than one container diameter between adjacent containers) reduced CF when the allotted area outside the container limited the potential amount of water that could be captured. Compared with impact sprinklers, wobbler sprinklers increased irrigation capture 7% for Ligustrum japonicum grown in 27-cm-diameter containers but not in 16-cm-diameter containers. Results showed that CF is a dynamic parameter that depends on canopy size, container size, container spacing, and sprinkler type. A working knowledge of CF is crucial for determining irrigation requirements to maximize sprinkler irrigation efficiency in container nurseries.
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Kurniawan, Aries Taufiq, Arief Budiman, Rachmawan Budiarto e Ridwan Budi Prasetyo. "Optimizing Energy Output for Oscillating Water Column (OWC) Wave Energy Converter System at Pantai Baron, Gunung Kidul, DI Yogyakarta". Applied Engineering and Technology 3, n.º 2 (26 de agosto de 2024): 125–32. https://doi.org/10.31763/aet.v3i2.1773.
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The prototypes of the Oscillating Water Column (OWC) system constructed by BPPT at Pantai Baron, Gunung Kidul, in 2005 and 2006 were not sustainable. Based on its condition and location, the root cause of the problem was defined. Maximizing the total efficiency and capacity factor (Cf) of the OWC system was the main factor for optimizing energy output. Collecting factors that constructed the total efficiency and capacity factor of the OWC system was conducted. Selecting the appropriate turbine, generator, and chamber system led to an increase in the total efficiency of the OWC system. Reducing the effect of wave diffraction, finding optimum wave data for forecasting, finding optimum water depth area to avoid wave breaking area, reducing corrosion chance by selecting the optimum height of the OWC system, and using a control system to minimize stalling on turbine were factors that constructed capacity factor
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Barthelmie, R. J., G. C. Larsen, M. Mølgaard Pedersen e S. C. Pryor. "Microscale modelling of wind turbines in the New York offshore lease area". Journal of Physics: Conference Series 2265, n.º 2 (1 de maio de 2022): 022040. http://dx.doi.org/10.1088/1742-6596/2265/2/022040.
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Abstract Simulations of the New York offshore wind energy lease area are undertaken within the PyWake program using both NOJ wake parameterization and the Fuga model. Seven different wind farm layouts are simulated to evaluate how the potential annual energy production (AEP) and capacity factor (CF) are impacted by the installed capacity (IC) density and the rotation of the wind turbines compared to the control. The control simulations use the east-west, north-south turbine layout with equidistant spacing of 1.85 km (7.7D) that will be used for the Vineyard Wind offshore wind farm south of Massachusetts. Both CF and AEP have an almost linear relationship with IC for the IC densities of 2.2 to 8.1 MWkm−2. Modelled CF are lower using Fuga (48.9% to 53.9%) than from NOJ (51.5% to 54.4%). The rotated turbine layouts have similar CF to the control because the wind direction distribution is dominated by peaks in both the southwest and northwest directions.
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Bystrova, Serafima G. "Features of determining the diffusion capacity of the lungs by carbon monoxide in cystic fibrosis children". Russian Pediatric Journal 25, n.º 5 (30 de outubro de 2022): 350–56. http://dx.doi.org/10.46563/1560-9561-2022-25-5-350-356.
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The article presents current literature data from English-language (search made in PubMed) and Russian-language (search made in eLibrary) sources about the method for measurement of the lung diffusing capacity for carbon monoxide in children with cystic fibrosis (CF). This review presents the general characteristics of this test in children and adults with various diseases, and also describes the conflicting results of studies using this method in CF patients of various ages and disease severity. The expediency, the informativeness, and difficulties of evaluation and interpretation of the test’s results, depending on the age and course of the disease of patients, are discussed. The author concludes that further research of interpretation of indicators determined during the test of the lung diffusing capacity for carbon monoxide, such as the transfer factor, alveolar volume, and their ratio in CF children is necessary.
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WIJAYA, FRANSISCO DANANG, I. WAYAN ADIYASA e EKRAR WINATA. "Analisis Faktor Kapasitas Pembangkit Listrik Hibrida PLTB dengan PLTD di Pulau Terpencil: Studi Kasus Elat Pulau Serau Maluku". ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 9, n.º 4 (10 de outubro de 2021): 746. http://dx.doi.org/10.26760/elkomika.v9i4.746.
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ABSTRAKRasio elektrifikasi di Indonesia belum mencapai 100%, penyebabnya antara lain masalah lokasi di daerah terpencil atau kepulauan dan mahalnya biaya operasi PLTD. Salah satu solusi adalah membangkitkan listrik berbasis energi terbarukan setempat. Tahap awal pemanfaatan energi terbarukan perlu dihitung faktor kapasitas (CF). Tujuan penelitian ini menganalisis CF untuk PLTB dengan metode perhitungan analitik berbasis potensi energi angin, spesifikasi teknologi PLTB dan PLTD, profil beban dan energi listrik yang dapat diproduksi untuk pengembangan sistem hibrida dengan mengambil kasus di Elat Pulau Serau Maluku. Hasil perhitungan CF untuk 5 teknologi PLTB yang berbeda dengan variasi ketinggian di Elat telah diverifikasi dengan simulasi menggunakan perangkat lunak HOMER dengan nilai rerata galat -0,030. Semakin tinggi PLTB, nilai CF semakin besar dengan konstanta 0,0030.Kata kunci: elektrifikasi, faktor kapasitas, PLTB, PLTD, sistem hibrida ABSTRACTThe electrification ratio in Indonesia has not reached 100%, the causes include problems with the location in remote areas or islands and the high operating costs of diesel power plant (DPP). One solution is to generate electricity based on local renewable energy. The initial stage of utilizing renewable energy needs to calculate the capacity factor (CF). The purpose of this research is to analyze CF for wind turbine generator (WTG) with analytical calculation methods based on wind energy potential, technology specifications of WTG and DPP, load profiles and electrical energy that can be produced for hybrid system development by taking the case in Elat Serau Island, Maluku. The results of CF calculations for 5 different WTG technologies with altitude variations in Elat have been verified by simulation using HOMER software with a mean error value of -0.030. The higher the WTG, the greater the CF value with a constant of 0.0030.Keywords: electrification, capacity factor, diesel power plant, wind turbine generator, hybrid system
Teses / dissertações sobre o assunto "Capacity factor (CF)"
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Kadkhodaei, Maryam. "Sensitivity of energy systems with large shares of variable renewable energies to climate data uncertainty and climate change". Electronic Thesis or Diss., Paris, EHESS, 2024. http://www.theses.fr/2024EHES0122.
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Décarboniser le système énergétique en augmentant l'utilisation des sources d'énergies renouvelables variables (ERV) est essentiel pour réduire les impacts du changement climatique et maintenir le réchauffement climatique en dessous de 2 °C. Les modèles de systèmes énergétiques sont utilisés pour planifier les futurs mélanges énergétiques et évaluer différentes options. À mesure que les sources d'ERV deviennent plus dominantes, ces modèles deviennent plus sensibles aux conditions météorologiques. Cela signifie qu'il est crucial de gérer les incertitudes liées à des facteurs tels que la modélisation des facteurs de capacité (FC) et les effets du changement climatique.Pour mieux comprendre les effets de l'incertitude dans la modélisation des FC, cette thèse examine la sensibilité des coûts totaux du système et de la capacité installée optimale du modèle de système énergétique EOLES aux perturbations uniformes et par quantiles des FC photovoltaïques (PV) et éoliens. Elle compare également la sensibilité lors de l'optimisation à la fois des investissements en capacité et de la gestion des flux, ainsi que lors de l'optimisation uniquement de la gestion des flux. De plus, nous comparons la sensibilité aux perturbations des FC avec celle des dépenses en capital (CAPEX). Les résultats indiquent que les sorties du système sont plus sensibles aux perturbations des FC éoliens qu'aux perturbations des FC PV. Pour les deux sources d'énergie, des impacts plus significatifs sont observés à des plages de quantiles plus basses, représentant des événements de faible production. Dans les systèmes avec une capacité installée fixe, les perturbations négatives entraînent des sensibilités nettement plus élevées que les perturbations positives. De plus, nous constatons que la sensibilité aux FC est comparable à celle des CAPEX. Notre étude suggère qu'une plus grande attention devrait être portée à la précision de la modélisation des FC des ERV, en particulier pour les événements de faible production, et que la planification de la capacité devrait tenir compte des chocs négatifs potentiels dans les FC des ERV.Nous analysons également l'effet du changement climatique sur le système énergétique en France. À cette fin, l'effet du changement climatique sur la demande énergétique ainsi que sur le FC des ERV (PV et éolien) est considéré, en utilisant une approche multi-modèles incorporant cinq modèles climatiques différents sous le scénario RCP8.5. L'analyse utilise le modèle de système énergétique EOLES pour simuler une représentation détaillée du mix énergétique de la France sans carbone. Nos résultats indiquent qu'avec le changement climatique, le coût total du système énergétique diminue principalement en raison des changements dans la gestion des flux et non de l'adaptation des capacités installées. La capacité installée optimale pour l'éolien et le PV diminue également. Notamment, l'étude montre que le changement climatique ne menace pas la sécurité de l'approvisionnement énergétique, même sans adaptation des capacités installées. De plus, l'analyse souligne que pour évaluer avec précision l'impact du changement climatique sur le système énergétique et planifier les capacités installées, il est crucial de considérer simultanément ses effets sur la demande énergétique et sur le FC des ERVDecarbonizing the energy system by increasing the use of variable renewable energy (VRE) sources is essential to reducing the impacts of climate change and keeping global warming below 2°C. Energy system models are used to plan future energy mixes and assess different options. As VRE sources become more dominant, these models become more sensitive to weather conditions. This means it is important to manage uncertainties related to factors like capacity factor (CF) modeling and the effects of climate change.To better understand the effects of uncertainty in CF modeling, this thesis investigates the sensitivity of total system costs and optimal installed capacity of the EOLES energy system model to both uniform and quantile range perturbations of PV and wind CFs. It also compares the sensitivity when optimizing both capacity investments and dispatch, as well as when optimizing only dispatch. Additionally, we compare the sensitivity to CF perturbations with that to capital expenditures (CAPEX). Results indicate that system outputs are more sensitive to wind CF perturbations than to PV. For both PV and wind, more substantial impacts are observed at lower quantile ranges, representing low-generation events. In systems with fixed installed capacity, negative perturbations lead to significantly higher sensitivities than positive ones. Moreover, we find that sensitivity to CFs is comparable to the sensitivity to CAPEX. Our study suggests that greater attention should be given to the accuracy of VRE CF modeling, particularly for low-generation events, and that capacity planning should account for potential negative shocks in VRE CF. We also analyze the effect of climate change on the energy system in France. To this end, the effect of climate change on both energy demand and the CF of VRE (PV and wind) is considered, using a multi-model approach incorporating five different climate models under the RCP8.5 scenario. The analysis uses the EOLES energy system model to simulate a detailed representation of carbon-free France's energy mix. Our findings indicate that with climate change, the total cost of the energy system decreases mainly because of changes in dispatch and not adapting the installed capacities. The optimal installed capacity of the wind and PV also decreases. Notably, the study shows that climate change does not threaten energy supply security, even without adaptation of installed capacities. Additionally, the analysis highlights that to accurately assess the impact of climate change on the energy system and plan for installed capacities, it is crucial to consider its effects on both energy demand and CF of VRE simultaneously
Capítulos de livros sobre o assunto "Capacity factor (CF)"
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Radtke, Thomas, Susi Kriemler e Helge Hebestreit. "Physical activity, exercise, and cystic fibrosis". In Oxford Textbook of Children's Sport and Excercise Medicine 4e, editado por Neil Armstrong e Willem van Mechelen, 355–68. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/med/9780192843968.003.0025.
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Abstract Cystic fibrosis (CF) is a genetic disease resulting in an impaired mucociliary clearance, chronic bacterial airway infection, and inflammation. The progressive destruction of the lungs remains the main cause for morbidity and premature death. Life expectancy has increased remarkably over the last decades because of improved diagnostics, treatment opportunities, and widespread implementation of newborn screening. Children and adolescents with CF are healthier than ever, and a substantial proportion can expect to live into their fifth decade. Highly effective CF transmembrane conductance regulator therapies are now available for the vast majority of children and adolescents and are having a major impact on children’s overall health status. Many children with mild CF lung disease have lower maximal aerobic exercise capacity with impaired skeletal muscle oxygen extraction and utilisation being an important contributing factor. In moderate and advanced lung disease, exercise intolerance is the consequence of multisystemic abnormalities of muscle, lung, and/or heart function. Although growing evidence suggests beneficial effects of regular physical activity on aerobic exercise capacity and rate of lung function decline, healthcare professionals often lack confidence in providing individualised physical activity advice to people with CF. More research is needed to better understand the pathophysiological mechanisms of exercise limitations and to find optimal physical activity and exercise modalities to support children and adolescents to benefit from the multiple positive effects of living a physically activity lifestyle, including lung health and quality of life.
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"Can you imagine why? Consider the following situations and decide whether they are also governed by the CISG (provided that the CISG applies to the residual contract): • an offer to adjust the purchase price; • an offer to terminate the contract amicably; • a settlement. Q4-4 Other uniform law does not show the same restriction in the scope of application. The UP 2004 and the PECL, for example, not only provide rules for the formation of contract and the remedies of the parties, but also deal with the validity of contract, except for the issue of illegality, immorality or lack of capacity. a) Why do you think the drafters of the CISG refrained from settling the above mentioned issues? b) Why are there no particular difficulties when dealing with those issues in the PECL and the UP 2004, respectively? Q4-5 What might have been the reason for excluding the issue of ownership from the Convention’s scope of application? Q4-6a) Does applicable domestic law invalidate a right to avoid the contract resulting from an application of the CISG? Cf. C4-1. b) According to C4-1, in deciding whether domestic law supersedes the CISG, what factors are to be taken into account?" In International Sales Law, 94–97. Routledge-Cavendish, 2007. http://dx.doi.org/10.4324/9780203945445-43.
Texto completo da fonteTrabalhos de conferências sobre o assunto "Capacity factor (CF)"
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Chowdhury, Souma, Jie Zhang, Achille Messac e Luciano Castillo. "Characterizing the Influence of Land Area and Nameplate Capacity on the Optimal Wind Farm Performance". In ASME 2012 6th International Conference on Energy Sustainability collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/es2012-91063.
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The development of utility-scale wind farms that can produce energy at a cost comparable to that of conventional energy resources presents significant challenges to today’s wind energy industry. The consideration of the combined impact of key design and environmental factors on the performance of a wind farm is a crucial part of the solution to this challenge. The state of the art in optimal wind project planning includes wind farm layout design and more recently turbine selection. The scope of farm layout optimization and the predicted wind project performance however depends on several other critical site-scale factors, which are often not explicitly accounted for in the wind farm planning literature. These factors include: (i) the land area per MW installed (LAMI), and (ii) the nameplate capacity (in MW) of the farm. In this paper, we develop a framework to quantify and analyze the roles of these crucial design factors in optimal wind farm planning. A set of sample values of LAMI and installed farm capacities is first defined. For each sample farm definition, simultaneous optimization of the farm layout and turbine selection is performed to maximize the farm capacity factor (CF). To this end, we apply the recently developed Unrestricted Wind Farm Layout Optimization (UWFLO) method. The CF of the optimized farm is then represented as a function of the nameplate capacity and the LAMI, using response surface methodologies. The variation of the optimized CF with these site-scale factors is investigated for a representative wind site in North Dakota. It was found that, a desirable CF value corresponds to a cutoff “LAMI vs nameplate capacity” curve — the identification of this cutoff curve is critical to the development of an economically viable wind energy project.
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Plume, Lauris, e Imants Plume. "Analysis of factors influencing energy efficiency of biogas plants". In 22nd International Scientific Conference Engineering for Rural Development. Latvia University of Life Sciences and Technologies, Faculty of Engineering, 2023. http://dx.doi.org/10.22616/erdev.2023.22.tf150.
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The number of biogas plants in Latvia has decreased by 9 plants, from 56 in 2017 to 47 in 2022. One of the reasons for this decrease in the number of biogas plants is low energy efficiency. The energy efficiency factor is influenced by different factors. Factors influencing the operation of the 49 biogas plants in 2020 were assessed, including the factor Installed electric power that is not changeable by the plant operator. Other factors constitute a group of factors that can be compensated in daily operation like a proportion of input biomass. The parameters of all factors were analyzed using statistical methods. Results of analyses show that there is no single factor having the effect on the capacity factor with statistically acceptable reliability. However, correlation analyses and the obtained linear regression revealed two most significant factors, i.e. the proportion of manure (MA) and proportion of silage (SIL) in feedstock whose combination gives statistically significant linear equation for assessment of changes in the capacity factor (CF) MAof biogas plant. This two-factor model can be used to evaluate the capacity factor of a biogas plant with a combined input of manure and silage in Latvia.
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Leighty, William C. "Running the World on Renewables: Hydrogen Transmission Pipelines With Firming Geologic Storage". In ASME 2008 Power Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/power2008-60031.
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The world’s richest renewable energy resources — of large geographic extent and high intensity — are stranded: far from end-users with inadequate or nonexistent gathering and transmission systems to deliver the energy. The energy output of most renewables varies greatly, at time scales of seconds to seasons: the energy capture assets thus operate at inherently low capacity factor (CF); energy delivery to end-users is not “firm”. New electric transmission systems, or fractions thereof, dedicated to renewables, will suffer the same low CF, and represent substantial stranded capital assets, which increases the cost of delivered renewable-source energy. Electric energy storage cannot affordably firm large renewables at annual scale. At gigawatt (GW = 1,000 MW) scale, renewable-source electricity from diverse sources, worldwide, can be converted to hydrogen and oxygen, via high-pressure-output electrolyzers, with the hydrogen pipelined to load centers (cities, refineries, chemical plants) for use as vehicle fuel, combined-heat-and-power generation on the retail side of the customers’ meters, ammonia production, and petroleum refinery feedstock. The oxygen byproduct may be sold to adjacent dry biomass and / or coal gasification plants. Figures 1–3. New, large, solution-mined salt caverns in the southern Great Plains, and probably elsewhere in the world, may economically store enough energy as compressed gaseous hydrogen (GH2) to “firm” renewables at annual scale, adding great market and strategic value to diverse, stranded, rich, renewable resources. Figures 2 and 3. For example, Great Plains, USA, wind energy, if fully harvested and “firmed” and transmitted to markets, could supply the entire energy consumption of USA. If gathered, transmitted, and delivered as hydrogen, about 15,000 new solution-mined salt caverns, of ∼8 million cubic feet (225,000 cubic meters) each, would be required, at an incremental capital cost to the generation-transmission system of ∼5%. We report the results of several studies of the technical and economic feasibility of large-scale renewables — hydrogen systems. Windplants are the lowest-cost new renewable energy sources; we focus on wind, although concentrating solar power (CSP) is probably synergistic and will become attractive in cost. The largest and richest renewable resources in North America, with high average annual windspeed and sunlight, are stranded in the Great Plains: extant electric transmission capacity is insignificant relative to the resource potential. Large, new, electric transmission systems will be costly, difficult to site and permit, and may be difficult to finance, because of public opposition, uncertainties about transmission cost recovery, and inherently low CF in renewables service. The industrial gas companies’ decades of success and safety in operating thousands of km of GH2 pipelines worldwide is encouraging, but these are relatively short, small-diameter pipelines, and operating at low and constant pressure: not subject to the technical demands of renewables-hydrogen service (RHS), nor to the economic challenge of delivering low-volumetric-energy-density GH2 over hundreds or thousands of km to compete with other hydrogen sources at the destination. The salt cavern storage industry is also mature; several GH2 storage caverns have been in service for over twenty years; construction and operating and maintenance (O&M) costs are well understood; O&M costs are low.
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Bruck, Maira, Navid Goudarzi e Peter Sandborn. "A Levelized Cost of Energy (LCOE) Model for Wind Farms That Includes Power Purchase Agreement (PPA) Energy Delivery Limits". In ASME 2016 Power Conference collocated with the ASME 2016 10th International Conference on Energy Sustainability and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/power2016-59608.
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The cost of energy is an increasingly important issue in the world as renewable energy resources are growing in demand. Performance-based energy contracts are designed to keep the price of energy as low as possible while controlling the risk for both parties (i.e., the Buyer and the Seller). Price and risk are often balanced using complex Power Purchase Agreements (PPAs). Since wind is not a constant supply source, to keep risk low, wind PPAs contain clauses that require the purchase and sale of energy to fall within reasonable limits. However, the existence of those limits also creates pressure on prices causing increases in the Levelized Cost of Energy (LCOE). Depending on the variation in capacity factor (CF), the power generator (the Seller) may find that the limitations on power purchasing given by the utility (the Buyer) are not favorable and will result in higher costs of energy than predicted. Existing cost models do not take into account energy purchase limitations or variations in energy production when calculating an LCOE. A new cost model is developed to evaluate the price of electricity from wind energy under a PPA contract. This study develops a method that an energy Seller can use to negotiate delivery penalties within their PPA. This model has been tested on a controlled wind farm and with real wind farm data. The results show that LCOE depends on the limitations on energy purchase within a PPA contract as well as the expected performance characteristics associated with wind farms.
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Kleiner, Yuri. "ORTHOEPY — HISTORY OF LINGUISTICS — HISTORY OF LANGUAGE". In 49th International Philological Conference in Memory of Professor Ludmila Verbitskaya (1936–2019). St. Petersburg State University, 2022. http://dx.doi.org/10.21638/11701/9785288062353.01.
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The definition of orthoepy as “a branch of linguistics that studies pronunciation norms” tends to determine the understanding of its tasks as exclusively prescriptive, and that of orthoepy as a whole as an applied area, par excellence. Its other component, purely linguistic, is present in the problem of the correlation between the system and the norm, traditionally central to the school of Lev Shcherba. In essence, this problem is a particular case of the Saussurian “language — speech” dichotomy, which is the reason for regarding orthoepy as a purely linguistic discipline and for discerning two points of view on its object, those “from within” and “from without.” The latter implies a conscious attitude towards the choice, from several possibilities, of one unit as a normative or “correct” with the establishment of the systemic status of this unit. This point of view on language, which emerged almost simultaneously with the awareness of it as an inherently human capacity (Plato), is reflected both in the early evidence of “language prestige” (Catullus, Cicero) and in the works of “intuitive linguists,” either relying on a certain norm (Alexandrian grammarians) or creating it (English orthoepists). In turn, the norm is synonymous to speech, which exists at a given synchronic stage; it changes either as a result of the alternative possibilities offered by the system (language dynamics) or due to the transition of the system to another synchronic stage (linguistic change per se), cf. Ludmila Verbitskaya’s formulation in The Linguistic Encyclopedic Dictionary: “The phonological system of a language completely determines the pronunciation norm. The norm can change within the system provided new forms gradually replace the old ones under the influence of extralinguistic factors or as a result of changes that have taken place in the system.” In this context, the primary task of interpreters of early orthoepic evidence (first of all, historians of language) is to identify factors belonging to two fundamentally different spheres. Ignoring this circumstance in the research procedures, characteristic of (chronologically or ideologically) pre–Saussurian (pre–Baudouin de Courtenay) linguistics, leads to a confusion of factors, including systemic and extra–linguistic ones, and, moreover, of the fundamental notions, (diachronic) change and (synchronic) variation, which, among other things, is reflected in the idea of ‘recent changes’ in the system (in fact, in the norm) and in the popular notion of “language in the state of (constant) flux.” On the contrary, the consistent differentiation, in research procedures, of different factors interacting in the functioning of language system, and thus discerning between the two points of view on it, “from within” and “from without,” makes orthoepy an integral part of linguistics as a fundamental science of language, providing theoretical justification for its applied component, the latter’s goals having been formulated, for all times, as a maxime to “speak properly and correctly.” Refs 29.
Relatórios de organizações sobre o assunto "Capacity factor (CF)"
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Rosero, Amparo, Iván Pastrana, Carlos Sierra, José Luis Pérez, Laura Espitia, Remberto Martínez e Hernando Araujo. Influence of genotype and environment on quality attributes of sweet potato (Ipomea batatas Lam.). Corporación Colombiana de Investigación Agropecuaria - AGROSAVIA, 2018. http://dx.doi.org/10.21930/agrosavia.poster.2018.7.
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Sweetpotato is the fifteenth most important food crop, and third between roots and tubers crops worldwide. Sweet potato crop has the capacity to adapt to different environmental conditions, and expression of quality traits is highly influenced by variety and growth conditions. We evaluate the effect of these factors on quality attributes such as dry matter content (DMC), ash content (AC), crude fiber (CF), total protein content (TPC) and brix grades (°Brix) in order to determine adequate conditions to ensure better quality in sweet potato roots.
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Putriastuti, Massita Ayu Cindy, Vivi Fitriyanti e Muhammad Razin Abdullah. Leveraging the Potential of Crowdfunding for Financing Renewable Energy. Purnomo Yusgiantoro Center, junho de 2021. http://dx.doi.org/10.33116/br.002.
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• Renewable energy (RE) projects in Indonesia usually have IRR between 10% and 15% and PP around 6 to 30 years • Attractive return usually could be found in large scale RE projects, although there are numerous other factors involved including technology developments, capacity scale, power purchasing price agreements, project locations, as well as interest rates and applied incentives. • Crowdfunding (CF) has big potential to contribute to the financing of RE projects especially financing small scale RE projects. • P2P lending usually targeted short-term loans with high interest rates. Therefore, it cannot be employed as an alternative financing for RE projects in Indonesia. • Three types of CF that can be employed as an alternative for RE project funding in Indonesia. Namely, securities, reward, and donation-based CF. In addition, hybrid models such as securities-reward and reward-donation could also be explored according to the project profitability. • Several benefits offer by securities crowdfunding (SCF) compared to conventional banking and P2P lending, as follows: (1) issuer do not need to pledge assets as collateral; (2) do not require to pay instalment each month; (3) issuer share risks with investors with no obligation to cover the investor’s loss; (4) applicable for micro, small, medium, enterprises (MSMEs) with no complex requirements; and (5) there is possibility to attract investors with bring specific value. • Several challenges that need to be tackled such as the uncertainty of RE regulations; (1) issuer’s inability in managing the system and business; (2) the absence of third parties in bridging between CF platform and potential issuer from RE project owner; (3) the lack of financial literacy of the potential funders; and (4) lastly the inadequacy of study regarding potential funders in escalating the RE utilisation in Indonesia.