1,720,997 research outputs found
Energy System Modeling: Investigating a decoupled approach to capital cost of energy storage and Vehicle-to-Grid in the European energy system
Full text linkEnergisystemer over hele verden er i et skifte mot mer bærekraftige måter å produsere energi på, drevet frem av de utfordringene med klimaendringer. Variable fornybare energikilder som vind- og solkraft har kommet fram som noen av de ledende energiproduksjonsteknologiene for et mer bærekraftig energisystem. Den naturlige variasjonen til vind- og solkraft endrer hvordan energisystemet fungerer, og nye kilder til energifleksibilitet er nødvendig for å balansere systemet. Flere tilgjengelige energilagringsteknologier kan i dag tilby den nødvendige fleksibiliteten, men spørsmålet om hvor stor lagringskapasitet og hvilke teknologier som vil fremtre som de mest økonomisk gunstige er ennå ikke besvart. Samtidig elektrifiseres mange sektorer, og det trengs mer elektrisk energi på tvers av energisystemer. En av de elektrifiserende sektorene er transportsektoren, med en økende popularitet for teknologier som batterielektriske kjøretøy.
I denne oppgaven brukes energisystemmodellering til å analysere to ting, effekten kostnadsstrukturen til energilagring har på energisystemet i energisystemmodellering, og funksjonaliteten til Vehicle-to-Grid (V2G) i energisystemmodellering. To modeller er utviklet ved bruk av GENeSYS-MOD og er utviklinger fra en tidligere utviklet modell av det europeiske energisystemet. Den første modellen, kalt Capex-modellen, endrer kostnadsstrukturen for energilagringsteknologier i modellen fra en LCOS-struktur til en CapEx-struktur. CapEx-strukturen deler kapitalkostnaden i to , kostnaden av energikapasitetsutvidelse og kostnaden av kraftkapasitetsutvidelse, i tillegg til å inkludere en variabel kostnad og en fast årlig kostnad. Sensitiviteter av ulike parametere er analysert for å gi innsikt i den nye modellen, og for å analysere robustheten til energilagringsteknologiene i modellen. Den andre modellen, kalt V2G-modellen, endrer måten elbiler bruker strøm fra nettet på i modellen, og implementerer en V2G-funksjon. I V2G-modellen er det en batterilagringsenhet mellom nettet og elbilene. Den nye V2G-funksjonen lar elbilene lades ut til nettet i tillegg til normal ladding og kjøring, med en V2G-ladekabelen kostnad på 22 €/kW. Den tidligere modellen som oppgaven tar utgangspunkt i, har ikke batteripakke mellom nettet og elbilene, noe som betyr at bilene bruker strøm fra nettet mens de kjører. Ulike ladescenarier og sensitiviteter på V2G-integrasjonsraten er analysert for V2G modellen.
Resultatene av Capex-modellen viser at CapEx-kostnadsstrukturen gir en mer konservativ investering i energikapasitet og kraftkapasitet i energilagringsteknologiene. Den konservative investeringen i Capex-modellen kan betraktes som mer realistisk enn investeringen sett i modellen med LCOS-strukturen, og en mer realistisk bruk av energilagrene kan bli sett i resultatene.
Resultatene av V2G-modellen viser en økt investering i elbiler på tvers av alle ladescenarier, mens investeringer i energilagring reduseres sammenlignet med Capex-modellen. Den nye fleksibiliteten introdusert til elbilene gjennom batteripakken og V2G-funksjonen reduserer behovet for fleksibiliteten som batterilagring tilbyr. Investeringen i elbiler faller og investeringene i energilagring øker med økende V2G-integrasjonsrate. Dette indikerer at modellen foretrekker å investere i litium-ion-batterier for kortsiktig energilagring fremfor å investere i V2G-ladekablene med en kostnad på 22 €/kW. Bruksmønsteret av de elektriske kjøretøyene er viser et urealistisk mønster i den nye modellen, og forverres ved høyere V2G-integrasjonsrater. Scenarioresultatene viser imidlertid at et strengere ladescenario gir de mest realistiske resultatene. For fremtidig arbeid vil implementering av lademønster og kjøremønster framstå som viktig for å sikre realistiske resultater ved bruk av metoden for V2G implementering som brukt i denne studien.
Totalt sett viser Capex-modellen fordelene med modellering med en CapEx-struktur, og en metode for hvordan det kan implementeres. V2G-modellen gir innsikt i hvordan V2G kan modelleres, og legger grunnlaget for videre energisystemmodellering med V2G. CapEx-modellen er mer eller mindre en modell klar for bruk, mens V2G-modellen krever videre arbeid, spesielt innen å begrense lademønsteret og kjøremønsteret til de V2G-deltakende bilene.Energy systems across the world are rapidly shifting towards more sustainable ways of energy production, propelled by the urgent challenges of climate change. Variable renewable energy sources such as wind and solar power have emerged as some of the leading energy production technologies for a more sustainable energy system. The natural variability of wind and solar power is changing how the energy system works, and new sources of energy flexibility are needed to balance the system. Several energy storage technologies available today can provide the needed flexibility, but the question of how much storage capacity and which technologies will emerge as the most economically feasible is still to be answered. At the same time, many sectors are electrifying, and more electric energy is needed across energy systems. One of the electrifying sectors, is the transportation sector, with technologies such as battery electric vehicles gaining popularity.
In this thesis energy system modeling is used to analyze two things, the effect the cost structure of energy storage has on the energy system in energy system modeling, and the functionality of Vehicle-to-Grid (V2G) in energy system modeling. Two models have been developed using GENeSYS-MOD and are derived from a previously developed model of the European energy system. The first model, named the Capex model, changes the cost structure of energy storage technologies in the model from an LCOS structure to a decoupled CapEx structure. The decoupled CapEx approach assigns a capital cost to both energy capacity expansion and power capacity expansion of the energy storage technologies as well as a variable cost and a fixed yearly cost. Sensitivities in different parameters are analyzed to give insight into the new model in general and into the robustness of the energy storage technologies in the model. The second model, named the V2G model, changes the way electric cars use electricity from the grid and implements a V2G function. In the V2G model, there is a battery storage unit between the grid and the electric cars. The new V2G function allows the electric cars to discharge to the grid as well as normal charging and driving, but the V2G charging cable comes at a cost of 22 €/kW. The previous model does not have a battery pack between the grid and the electric cars, meaning the cars use electricity from the grid as it is driving. Different charging scenarios and sensitivities on the V2G integration rate are studied to analyze the modeling approach.
The results of the Capex model show that the decoupled CapEx cost structure gives a more conservative investment in energy capacity and power capacity in energy storage technologies. The conservative investment in the Capex model can be thought of as more realistic than the investment seen in the model with the LCOS approach as the dispatch of the storage technologies reminisces better with what is expected in reality.
The results of the V2G model show an increased investment in electric cars across all charging scenarios while energy storage investment decreases when compared to the Capex model. The flexibility introduced to the electric cars through the battery pack and the V2G function decreases the need for the day-to-day flexibility that utility-scale battery storage provides. The investment in electric cars drops and investment in energy storage increases with an increasing V2G integration rate. This indicates that the model prefers to invest in utility-scale lithium-ion batteries for short-term energy storage rather than investing in the V2G charging cables at a cost of 22 €/kW. The dispatch of the electric vehicles is to some degree flawed within the new model, and only worsens at higher V2G integration rates. However, the scenario results show that a stricter charging scenario provides the most realistic results. For future work, the implementation of charging patterns and driving patterns are integral for securing realistic results when applying the method for V2G used in this study.
Overall the Capex model shows the benefits of modeling with a decoupled CapEx approach, and a method of how to apply it. The V2G model has given insights into how V2G can be modeled, and lays the groundwork for further research in V2G modeling. The CapEx model is more or less a model ready for application, while the V2G model requires further work especially within restricting the charging patterns and driving patterns of the V2G participating cars
GENeSYS-MOD Transport Sensitivities: Data and model code for Hainsch (preprint): Identifying policy areas for the transition of the transportation sector
No full textThis dataset contains all GENeSYS-MOD input data for Hainsch (preprint): Identifying policy areas for the transition of the transportation sector. doi: 10.5281/zenodo.6919452.
With the input data files and the GAMS files, the model results presented in the preprint can be replicated.
Furthermore, the output folder contains the result files for the base case and all sensitivities as well as the Tableau files which were used to generate the result figures
Identifying policy areas for the transition of the transportation sector
No full textBeing the only energy sector where emissions are still at 1990 levels, the German transportation sector requires rapid decarbonization to achieve ambitious climate targets. Policy makers need to put the framework in place which enables and supports this transition. This work analyzes which policy areas should be targeted considering interactions with and implications for the entire energy system. The Global Energy System Model (GENeSYS-MOD) is used to compute 400 sensitivities which showcase the effectiveness of specific transport and energy system related policies. Shifting transportation demand to less energy and emission intensive modes or avoiding it in the first place shows the strongest effect on a number of key metrics. Primary energy consumption, emissions, and fleet size can all be reduced through a combination of electrification and shift towards public transport and long-distance trains. Carbon prices also showcase significant effects while further affecting the other energy sectors. The results suggest that in the intermediate term, modal shift and demand reduction can help with reducing transportation related emissions, while carbon prices are effective after 2040.EC/H2020/835896/EU/Open ENergy TRansition ANalyses for a low-carbon Economy/Open ENTRANC
Identifying policy areas for the transition of the transportation sector
No full textAbstract:
Being the only energy sector where emissions are still at 1990 levels, the German transportation sector requires rapid decarbonization to achieve ambitious climate targets. Policy makers need to put the framework in place which enables and supports this transition. This work analyzes which policy areas should be targeted considering interactions with and implications for the entire energy system. The Global Energy System Model (GENeSYS-MOD) is used to compute 400 sensitivities which showcase the effectiveness of specific transport and energy system related policies. Shifting transportation demand to less energy and emission intensive modes or avoiding it in the first place shows the strongest effect on a number of key metrics. Primary energy consumption, emissions, and fleet size can all be reduced through a combination of electrification and shift towards public transport and long-distance trains. Carbon prizes also showcase significant effects and also affects the other energy sectors. The results suggest that in the intermediate term, modal shift and demand reduction can help with reducing transportation related emissions, while carbon prices are effective after 2040
modellgestützte Identifizierung von No-regret-Optionen unter verschiedenen Arten von Unsicherheit
No full textThis dissertation details possible pathways for the European and German energy transition. The open source Global Energy System Model (GENeSYS-MOD) is applied, a multisectoral long-term energy system model, to apply different methodologies accounting for uncertainty in the future energy system. With the goal of outlining challenges and opportunities of the energy system transformation, this dissertation provides common findings and no-regret options found across multiple studies.
Part I of this dissertation focuses on decarbonization pathways and 100% renewable energy systems in Europe. Numerous energy system models are being used, raising the need to adequately assess their results if policy and decision makers should take well-informed decisions. The first chapter draws from previous experience of modeling 100% renewable energy systems and outlines lessons learned from these exercises. Various energy transition pathways are then analyzed and common findings are synthesized which are compared to the efforts of the European Green Deal (EGD). Thereafter, the effects that short sighted decision making could have on the energy system, especially regarding the problem of stranded assets. Key findings of this part highlight the need for open science and clear result communication.
In Part II, challenges and opportunities for the German Energiewende are discussed. It starts by providing a comparison of five different energy system models and analyzes the impact of Germany’s 2030 climate targets on the power system. The following two Chapters explore the effects of key drivers and influential factors on the German energy transition and transportation transition, in particular. Parametric sensitivity analysis is performed, highlighting areas with high impact which policy makers should focus on. It can be shown that demand reductions, next to costs of renewables and carbon prices, have the highest effect on multiple indicators relevant to the success of the energy transition.
Across all chapters of this dissertation, different methodologies to account for various types of uncertainty are applied. The results showcase that, despite uncertain future developments, common findings can be found and no-regret options formulated. In doing so, this dissertation contributes to the ongoing scientific and public debate by showcasing possible pathways, chances, and barriers of the European and German energy transition. In addition, the principles of open science are followed, allowing other researchers or practitioners to validate the findings and use the applied methodologies.In dieser Dissertation werden mögliche Pfadverläufe für die europäische und deutsche Energiewende beschrieben. Das quelloffene Global Energy System Model (GENeSYS-MOD), ein multisektorales Langfrist-Energiesystemmodell, wird eingesetzt, um verschiedene Methoden zur Berücksichtigung von Unsicherheiten im zukünftigen Energiesystem anzuwenden. Mit dem Ziel, die Herausforderungen und Chancen der Energiewende zu skizzieren, leitet diese Dissertation gemeinsame Erkenntnisse aus mehreren Studien ab.
Teil I dieser Dissertation analysiert Dekarbonisierungspfade und 100% erneuerbare Energiesysteme in Europa. Eine steigende Anzahl an Energiesystemmodellen erfordert eine angemessene Bewertung ihrer Ergebnisse, wenn Politiker:innen und Entscheidungsträger:innen gut informierte Entscheidungen treffen sollen. Das erste Kapitel stützt sich auf gesammelte Erfahrungen mit der Modellierung von 100% erneuerbaren Energiesystemen und umreißt die Lehren, die aus diesen Analysen gezogen wurden. Gemeinsame Erkenntnisse aus verschiedene Energiewendepfade werden zusammengefasst, die mit den Bemühungen des European Green Deal (EGD) verglichen werden. Danach werden die Auswirkungen kurzsichtiger Entscheidungsfindung auf das Energiesystem, insbesondere im Hinblick auf das Problem der stranded-assets, dargestellt. Die Ergebnisse dieses Teils unterstreichen die Notwendigkeit klarer Ergebniskommunikation und einer offenen Wissenschaft.
In Teil II werden Herausforderungen und Chancen für die deutsche Energiewende diskutiert. Fünf verschiedenen Energiesystemmodelle werden verglichen und die Auswirkungen der 2030 Klimaziele auf das Stromsystem analysiert. Anschließend werden die Auswirkungen der wichtigsten Treiber und Einflussfaktoren auf die deutsche Energiewende und insbesondere die Verkehrswende untersucht. Es wird eine parametrische Sensitivitätsanalyse durchgeführt, die Bereiche mit hohen Auswirkungen hervorhebt, auf die sich politische Entscheidungsträger: innen konzentrieren sollten. Es zeigt sich, dass Nachfragereduzierungen, neben den Kosten für erneuerbare Energien und den Emissionspreisen, den größten Einfluss auf mehrere für den Erfolg der Energiewende relevante Indikatoren haben.
In allen Kapiteln dieser Dissertation werden unterschiedliche Methoden zur Berücksichtigung verschiedener Arten von Unsicherheit angewandt. Die Ergebnisse zeigen, dass trotz unsicherer zukünftiger Entwicklungen gemeinsame Erkenntnisse gefunden und no-regret Optionen formuliert werden können. Damit leistet diese Dissertation einen Beitrag zur laufenden wissenschaftlichen und öffentlichen Debatte, indem sie mögliche Pfade, Chancen und Barrieren der europäischen und deutschen Energiewende aufzeigt. Darüber hinaus wird den Prinzipien der offenen Wissenschaft gefolgt, die es anderen Forscher:innen ermöglicht, die Ergebnisse zu validieren und die angewandten Methoden zu nutzen.BMBF, 01LN1704A, Nachwuchsgruppe Globaler Wandel: CoalExit - Die Ökonomie des Kohleausstiegs - Identifikation von Bausteinen für Rahmenpläne zukünftiger regionaler StrukturwandelEC/H2020/835896/EU/Open ENergy TRansition ANalyses for a low-carbon Economy/Open ENTRANC
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
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