1,720,957 research outputs found
Techno-economic optimization of utility-scale battery storage integration with a wind farm for wholesale energy arbitrage considering wind curtailment and battery degradation
Full text linkIntegrating energy storage into renewable generation systems offers significant potential for enhancing revenue streams. This study conducts a comprehensive long-term techno-economic analysis of integrating a battery energy storage system (BESS) with an existent wind farm for wholesale energy arbitrage and wind curtailment mitigation. The study identifies the optimal battery size and the corresponding optimal scheduling operations using a computationally efficient optimization framework formulated as a mixed-integer linear programming (MILP) problem. The MILP model maximizes net profit by considering real-world operational data, including wholesale electricity prices, wind generation, and transmission system operator dispatching orders from the Italian electricity market. Additionally, a cycle-counting battery degradation model is incorporated to account for the effects of battery ageing on the system performance. The study compares the financial performance of the wind-battery system with a scenario without storage, evaluating key energy, economic, and design indicators derived from the optimization results. Sensitivity analyses are performed, considering the most relevant key performance indicators, such as battery cost, battery efficiency, and wind curtailed energy. Results indicate that the highest net present value (NPV) of 152 k€ is achieved with a 1-h BESS of 4 MW / 4 MWh, while a 2-h BESS configuration with a size of 2 MW/4 MWh yields an NPV of 142 k€. The sensitivity analysis on battery capital expenditure cost reveals that for the integration of the battery into an existing wind farm to be financially viable, the battery cost must decrease below 325 €/kWh to achieve an interest rate of return (IRR) hurdle rate of 8–9 %. This work demonstrates the profitability potential of coupling BESS with wind farms and provides actionable insights for optimizing storage configurations in competitive electricity markets. Future work will expand the analysis to include ancillary services and uncertainty modeling further to enhance the economic and operational value of BESS integration
Optimisation of green hydrogen production for hard-to-abate industries: An Italian case study considering national incentives
Full text linkGreen hydrogen has emerged as a promising energy vector for the decarbonisation of heavy industry. The EU and national governments have recently introduced incentives to address the high costs of green hydrogen production and accelerate the economic development of hydrogen. This study investigates the local production of green hydrogen to decarbonise the high-temperature process heat demand of a heavy industry located in Italy. The hydrogen generation is powered by PV electricity and from the electric grid. We have optimised the sizes of the energy system components, including battery storage and hydrogen tanks. The Levelised Cost of Hydrogen (LCOH) was found to be 7.7 EUR/kg in the unincentivised base scenario, but this amount significantly reduced to 3.3 EUR/kg when incentives on hydrogen production in abandoned industrial areas were considered. Thanks to such incentives, the greenhouse gas emissions decreased by as much as 85 %, with respect to the non-incentivised base case. Our results show that the effect of the incentives on the design and economics of the system is comparable with the expected reductions in equipment costs over the next decade. Importantly, our findings reveal a linear relationship between Capital Costs and LCOH, thereby enabling precise cost estimations to be made for the considered location without any further simulations. A side effect of the size optimisation in the presence of incentives is an increase of the plant footprint. However, the limited availability of land could lead to non-optimal configurations with important impacts on emission intensity and LCOH
Ageing and energy performance analysis of a utility-scale lithium-ion battery for power grid applications through a data-driven empirical modelling approach
Full text linkEnergy storage systems are becoming one of the most relevant technologies to effectively support renewable energy source (RES) deployment at large. The present work proposes a detailed ageing and energy analysis based on a data-driven empirical approach of a real utility-scale grid-connected lithium-ion battery energy storage system (LIBESS) for providing power grid services. The system under investigation is an operative utility-scale LIBESS integrated with a multi-MW PV plant and connected to the medium voltage network, located in Southern-Italy. The ageing and energy analysis has been performed using data measured by the supervisory control and data acquisition (SCADA) system directly connected with the LIBESS. This large amount of data is collected in a cloud database and then elaborated using proper software tools. This experimental campaign applied on a commercial LIBESS covers the impact of degradation mechanisms, such as cycle and calendar ageing, the battery and global system efficiency as well as the role of auxiliaries’ power consumption under normal and power grid services operations. Thanks to the low complexity of the proposed data-driven model, it could be easily replicated in any other LIBESS facility, both operative in real-world framework and in laboratory context. The state-of-health (SOH) estimated by the degradation model implemented in this work after 3 years of operations and after 356 full-cycles equivalents is equal to 95.88 %, with an average capacity loss compared to the nominal capacity of about 1.37 % per year. Energy analysis revealed an average system global efficiency of 85 % for operations close to the nominal power that decreases to 65 % for operations at low power rates. While
considering the grid network services operations, the power grid applications investigated are primary frequency regulation, secondary voltage regulation and PV unbalances reduction. Our results show that primary frequency regulation is the most efficient service in terms of ageing and energy performances. It has been evaluated a capacity loss of 0.03 kWh per each full-cycle equivalent performed during primary frequency regulation. Differently, secondary voltage regulation and PV unbalances reduction present a capacity loss of 0.1 kWh and of 0.05 kWh per each full-cycle equivalent, respectively. At the same time, the global efficiency of primary regulation (around 83 %) is remarkably higher compared to secondary voltage regulation (about 47 %) and to PV unbalances reduction (about 55 %). Results support the relevance to identify the most impacting key performance indicators for effective exploitation of LIBESS in power system and network services applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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