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An adsorption based cooling solution for electronics used in thermally harsh environmentsSinha, Ashish 30 August 2010 (has links)
Growing need for application of electronics at temperatures beyond their rated limit, (usually > 150 °C) and the non availability of high temperature compatible electronics necessitates thermal management solutions that should be compact, scalable, reliable and be able to work in environments characterized by high temperature (150 -250 °C), mechanical shock and vibrations. In this backdrop the proposed research aims at realization of an adsorption cooling system for evaporator temperatures in the range of 140 °C-150 °C, and condenser temperature in the range of 160 °C-200 °C. Adsorption cooling systems have few moving parts (hence less maintenance issues), and the use of Thermo-Electric (TE) devices to regenerate heat of adsorption in between adsorbent beds enhances the compactness and efficiency of the overall 'ThermoElectric-Adsorption' (TEA) system. The work presented identifies the challenges involved and respective solutions for high temperature application. An experimental set up was fabricated to demonstrate system operation and mathematical models developed to benchmark experimental results. Also, it should be noted that TEA system comprises TE and adsorption chillers. A TE device can be a compact cooler in its own right. Hence a comparison of the performance of TEA and TE cooling systems has also been presented.
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A study of the meteorological conditions associated with anomalously early and anomalously late openings of a Northwest Territories winter road /Knowland, Katherine Emma. January 2008 (has links)
In the Canadian arctic, winter roads are engineered across the frozen land, rivers, and lakes. The strength and longevity of these roads depends on particular weather conditions. / Our research focuses on the winter road between Tulita and Norman Wells, Northwest Territories, open since 1982. The opening dates for the winter road are statistically analyzed. Five extreme early-opening years and five extreme late-opening years are determined and subsequently compared to both surface weather observations and large-scale synoptic structures prior to the opening dates for these years. Results show extreme late years are strong El Nino seasons, and extreme early years are colder and have more precipitation during November, than the 1971--2000 climatology. / The analysis of meteorological conditions near Norman Wells, associated with the extreme opening dates for this winter road, provides planners with more precise information germane to this road construction.
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A study of the meteorological conditions associated with anomalously early and anomalously late openings of a Northwest Territories winter road /Knowland, Katherine Emma. January 2008 (has links)
No description available.
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Influência das condições meteorológicas na concentração do benzeno e tolueno na Região Metropolitana de São Paulo: interação com outros poluentes / Influence of meteorological conditions on the concentration of benzene and toluene in the Metropolitan Region of São Paulo: interaction with other pollutantsSanchez, Dayana Yordy 26 February 2019 (has links)
Os hidrocarbonetos (HCs) aromáticos monocíclicos, como o benzeno e o tolueno, estão entre os compostos orgânicos voláteis (COVs) de grande interesse tanto para estudos dereatividade atmosférica, devido à contribuição para formação de smog fotoquímico, quanto por efeitos nocivos diretos à saúde humana. A evaporação e queima incompleta de combustíveis é a principal fonte de benzeno e tolueno, além de atividades industriais e uso de solventes. A Região Metropolitana de São Paulo (RMSP) é uma das maiores aglomerações urbanas do mundo com 21 milhões de habitantes e frota de mais de 7 milhões de veículos. A poluição do ar, com destaque para eventos de smog fotoquímico com altas concentrações de ozônio, tem sido um dos grandes problemas ambientais da RMSP. Devido à importância do benzeno e tolueno, a Companhia Ambiental do Estado de São Paulo (CETESB) iniciou o monitoramento destes compostos com frequência horária na estação Pinheiros, em conjunto com o monitoramento de outros poluentes. Neste trabalho avaliou-se o efeito das condições meteorológicas na variabilidade temporal da concentração do benzeno e tolueno medidos na estação Pinheiros durante o ano 2017, e as interações com outros poluentes (NO2,O3e CO). As concentrações mais altas foram observadas no período do inverno e a primavera (julho, agosto e setembro), decorrentes das condições desfavoráveis à dispersão dos poluentes, com máximos de 2,81 e 14,2 ppbv para benzeno e tolueno respectivamente, 3,70 ppm para CO, 203 e 208 g/m3para NO2 e O3, respectivamente. Os valores de concentração máxima do benzeno, tolueno, CO e NO2 foram obtidos entre as 08 e 10 h da manhã e depois das 20 h, coincidindo com os horários de maior tráfego, e, portanto, aumento das emissões por queima de combustíveis. Valores mínimos foram obtidos entre as 13 e 18 h, associados à diluição e remoção em função do aumento da altura da camada de mistura e/ou da velocidade do vento nestes horários; assim como processos de remoção por reações fotoquímicas. A variação diária da concentração do O3,apresentou níveis mínimos de manhã cedo entre as 6 e 8 horas, iniciando uma subida por volta das 10 horas, atingindo os valores máximos as 15 horas. O benzeno e tolueno apresentaram correlação positiva significativa (r > 0,8) com o CO, reforçando influência das emissões veiculares. Análise mais detalhada para agosto de 2017 mostrou a complexidade das condições meteorológicas afetando a concentração dos compostos estudados, envolvendo eventos sinóticos como a passagem de frentes frias (FF) determinantes na diminuição na concentração de benzeno e tolueno. Enquanto que dias em que as alturas da camada limite convectiva e estável foram abaixo de 500m apresentaram concentrações mais altas de poluentes. / Monocyclic aromatic hydrocarbons (HCs), such as benzene and toluene, are among the volatile organic compounds (VOCs) of great interest for both atmospheric reactivity studies, due to their contribution to the formation of photochemical smog, and for direct harmful effects on human health. The evaporation and incomplete burning of fuels is the main source of benzene and toluene, as well as industrial activities and the use of solvents. The Metropolitan Region of São Paulo (RMSP) is one of the largest urban agglomerations in the world with 21 million inhabitants and more than 7 million vehicles. Air pollution, especially photochemical smog events with high concentrations of ozone, has been one of the major environmental problems for RMSP. Due to the importance of benzene and toluene, the Environmental Company of the State of São Paulo (CETESB) began an hourly monitoring of these pollutants, among others, at Pinheiros Station. This work evaluated the meteorological conditions effects on the temporal variability of the benzene and toluene concentration and their interaction with other pollutants (NO2, O3 and CO) measured at the Pinheiros station during 2017. The highest concentrations were observed during winter (July, August and September), due to the unfavorable conditions for dispersion of pollutants, with maximums of 2.81 and 14.2 ppbv for benzene and toluene, respectively, 3.70 ppm for CO; 203 and 208 g/m3 for NO2 and O3, respectively. The maximum concentration values of benzene and toluene were obtained between 08 and 10 a.m. and after 8 p.m., due to the heaviest traffic, at that time, which increases fuel-burning emissions. The minimum values were obtained between 1 and 6 p.m., which was associated to the dilution and transport as a function of the increase of the height of the mixture layer and/or the wind speed, as well as processes of removal by photochemical reactions. These compounds showed a significant positive correlation (r> 0.8) with CO, reinforcing the influence of vehicular emissions. More detailed analyses for August 2017 showed the complexity of the meteorological conditions affecting the concentration of the studied compounds. For example, synoptic events such as the passage of cold fronts (FF) caused the decrease in the concentration of benzene and toluene, while higher concentrations of benzene and toluene were associated with convective and stable layer conditions below 500 m.
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The Influence of Synoptic Weather Conditions on Weekday-weekend Effect of Extreme Ground-level Ozone Events in the Toronto areaLeung, Kinson He Yin 10 January 2011 (has links)
Ground-level ozone (O3) is a familiar pollutant because it is associated with summer haze and smog alerts. The 2000-2008 weekday-weekend variations of ozone concentration were examined in relation to the Toronto weather conditions. The goal of this work is twofold: (1) To determine whether extreme ozone events were associated with specific weather conditions, (2) To determine whether the weekday-weekend effect of extreme ozone events could be detectable during the nine-year study period. The results show that in the study period, there were totally 313 days having extreme ground-level ozone events with ozone concentration ≥ 80 ppb, which is the current Ontario Ambient Air Quality Criterion for ozone concentration, in the four selected Toronto sites. Additionally, the weather condition mainly associated with these 313 days was the Dry Tropical one. This study also shows the phenomenon of the weekday-weekend effect of extreme ozone events in the past nine years in Toronto.
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The Influence of Synoptic Weather Conditions on Weekday-weekend Effect of Extreme Ground-level Ozone Events in the Toronto areaLeung, Kinson He Yin 10 January 2011 (has links)
Ground-level ozone (O3) is a familiar pollutant because it is associated with summer haze and smog alerts. The 2000-2008 weekday-weekend variations of ozone concentration were examined in relation to the Toronto weather conditions. The goal of this work is twofold: (1) To determine whether extreme ozone events were associated with specific weather conditions, (2) To determine whether the weekday-weekend effect of extreme ozone events could be detectable during the nine-year study period. The results show that in the study period, there were totally 313 days having extreme ground-level ozone events with ozone concentration ≥ 80 ppb, which is the current Ontario Ambient Air Quality Criterion for ozone concentration, in the four selected Toronto sites. Additionally, the weather condition mainly associated with these 313 days was the Dry Tropical one. This study also shows the phenomenon of the weekday-weekend effect of extreme ozone events in the past nine years in Toronto.
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Monitoring the effects of drought on wheat yields in SaskatchewanChipanshi, Aston Chipampe 01 January 1996 (has links)
In order to reduce the vulnerability of wheat production to drought, a calibrated and validated CERES Wheat crop simulation model was used to predict wheat yields on major soil textural groups using historical weather data at Swift Current, Saskatoon and Melfort. Yields were predicted using a run-out technique which involved the use of actual weather data to the prediction date and historical weather data from 1960 to 1990 for the remainder of the growing season. Yield predictions were made at five Julian dates during the crop calendar and these dates coincided with crop emergence, terminal spikelet initiation, end of the vegetative growth, heading and start of grain filling. Three sample years were used as case studies to test the applicability of the run-out method in making yield predictions. Sample base years were those with the lowest, medium and highest yields between 1960 and 1990 and these were selected from ranked yield values using quartiles. Test years were termed base years and weather files that were joined with the test years were run-out years. Each base year had 30 run-out years (1960-1990) and the mean of each run-out year was compared with the observed yield at the end of the season. Run-out yields for each base year were summarised as simple probability distributions so that yields exceeding certain values could be selected. Run-out yields at five prediction dates were found to be in close agreement with observed yields at the end of the growing season. To account for the variability in yields that can be found between places within the same climatic zone, simulated yields were re-classified by soil type and water stress level. These modifiers (soil type and water stress level) showed that chances of getting high yields diminish from Melfort to Swift Current at all prediction points due to the high variability of yield factors. Yield predictions that were made as above suggested that if historical weather records are combined with available weather data during the growing season, a good indication of yields can be obtained ahead of the harvest time and this could allow producers and those in the agri-business to decide on alternative actions of minimizing losses when prospects of getting a good yield are poor.
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Food quality, fasting periods and temperature stress : effects of energy challenges on the feeding patterns of avian nectarivoresKohler, Angela 12 October 2009 (has links)
The small size of nectarivorous birds is associated with high mass-specific metabolic rates and energetic lifestyles. Their energy balance is likely to be strongly influenced by environmental factors. Firstly, nectar varies in sugar concentration between different food plants and birds must adjust their consumption to maintain a constant energy intake. Secondly, unfavourable weather conditions, such as storms and heavy rains, may prevent birds from feeding, and they must increase their energy intake to compensate for the loss in foraging time. Low ambient temperature, as a third energetic challenge, results in higher energy demands for thermoregulation, which leads to increased food intake. However, these compensatory feeding responses may be constrained by physiological limitations to nectar ingestion, digestion and osmoregulatory processes. My research focused on the behavioural and physiological responses of captive sunbirds (Nectariniidae) and honeyeaters (Meliphagidae) to energetic challenges, namely variations in nectar quality and availability and in ambient temperature. For sunbirds, I also investigated on a novel short-term scale how feeding patterns are adjusted in order to compensate for alterations in energy intake or requirements. Feeding events were recorded using a photodetection system, and body mass was monitored continuously by connecting the perches to electronic balances, interfaced to a computer. Whitebellied sunbirds (Cinnyris talatala) were fed various nectar sugar concentrations. Their feeding durations were found to provide an estimate of meal size on all food concentrations. When exposed to a decrease in sugar concentration, birds generally demonstrated an increased feeding frequency and food intake within 10 min. The number and duration of meals increased in the first few minutes after return of a more concentrated diet. When whitebellied sunbirds and brown honeyeaters (Lichmera indistincta) were exposed to a 2 h fasting period during the day, they increased their nectar intake and energy accumulation after the fast. Sunbirds achieved this by increasing meal size but not meal frequency. However, both species weighed less in the evening following the fast than the previous evening, indicating that the compensation for lost foraging time was incomplete. During acute cold exposure, whitebellied sunbirds, amethyst sunbirds (Chalcomitra amethystina) and brown honeyeaters increased their nectar intake, but lost body mass irrespective of nectar sugar concentration. Honeyeaters ingested more food at subsequent cold exposure, suggesting physiological adaptation to high feeding rates. A chemical reactor model of digestive capacity, which assumes sucrose hydrolysis to be the limiting step in nectar digestion, accurately predicted maximal food intake in honeyeaters, but mostly underestimated it in sunbirds. Sugar assimilation efficiency was higher than 99% in whitebellied sunbirds and brown honeyeaters. Lastly, licking frequencies and tongue loads of whitebellied and amethyst sunbirds were investigated. In both species, tongue lick duration increased, and licking frequency and consumption per lick decreased, with increasing nectar concentration. Birds did not adjust their licking behaviour after a fasting period. In conclusion, the response to varied energy challenges is shaped by both compensatory feeding and physiological constraints. Although unrelated, sunbirds and honeyeaters showed convergence in their responses, probably due to their similar nectarfeeding lifestyle. / Thesis (PhD)--University of Pretoria, 2009. / Zoology and Entomology / unrestricted
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Beitrag zur Dimensionierung des Platzangebotes im ÖPNV in Abhängigkeit wetterbedingten Fahrgastverhaltens in touristisch geprägten RegionenLux, Beate 11 October 2022 (has links)
Die vorliegende Arbeit beinhaltet die Entwicklung eines Verfahrens zur Berücksichtigung wetterabhängiger Nachfrageszenarien im ÖPNV. Mittels statistischer Methoden wird unter Einbeziehung sachlogischer Kenntnisse zunächst die Nachfrage hinsichtlich ihrer Wetterabhängigkeit analysiert. Damit werden Schichtungen identifiziert, bei denen die bisher aufgetretenen Nachfrageschwankungen einer Wetterabhängigkeit unterlagen. Anhand der ermittelten Ergebnisse können sowohl kapazitätsrelevante als auch kapazitätsunabhängige Maßnahmen zur Verbesserung der Dienstleistungsqualität oder der Effizienz des Ressourceneinsatzes abgeleitet werden.
Ob die Wetterabhängigkeit der Nachfrage eine Veränderung des Platzangebotes erfordert, und ob diesen Erfordernissen entsprochen werden kann, wird ebenfalls geprüft. Das Verfahren wurde anhand von Nachfragedaten für fünf Eisenbahnlinien der Usedomer Bäderbahn getestet. Detaillierte Untersuchungen zu Möglichkeiten und Grenzen kurzfristiger Kapazitätsanpassungen ergänzen die Verfahrensentwicklung.:GELEITWORT
ABSTRACT
TABELLENVERZEICHNIS
ABBILDUNGSVERZEICHNIS
BEGRIFFE UND ABKÜRZUNGEN
FORMELVERZEICHNIS
1 Motivation, Zielstellung und Aufbau der Arbeit
2 Wetterabhängigkeit der Verkehrsnachfrage
2.1 Verkehrsbedarf und Verkehrsnachfrage
2.2 Wetterabhängigkeit der Verkehrsnachfrage
2.3 Verkehrsnachfrage durch den Freizeitverkehr
2.4 Wetterabhängigkeit von Freizeitaktivitäten
2.5 Zusammenfassung zum Stand der Forschung in Bezug auf die Wetterabhängigkeit der Verkehrsnachfrage
3 Kapazitätsplanung als wesentliche Planungsaufgabe im ÖPNV
3.1 Begriff Kapazität
3.2 Aufgabe der Kapazitätsplanung im Handlungsumfeld des ÖPNV
3.3 Verantwortlichkeiten für die Kapazitätsplanung
3.4 Anspruchsgruppen gegenüber der Kapazitätsplanung
3.5 Einordnung der Kapazitätsplanung in die Abfolge der Planungsaufgaben bei der Erstellung von Verkehrsangeboten
3.6 Allgemeiner Prozessablauf bei der Kapazitätsplanung
3.7 Beschreibung der Nachfrage als Basis für die Kapazitätsplanung
3.8 Nachfrageunabhängige Einflussgrößen und Randbedingungen
3.9 Fahrtgenaue Kapazitätsdimensionierung je Betriebstag als Input weiterer Planungsschritte
3.10 Disposition von Fahrzeugen und Personal
3.11 Schlussfolgerungen für die Berücksichtigung wetterabhängiger Nachfrageschwankungen bei der Kapazitätsplanung
4 Möglichkeiten und Grenzen kurzfristiger Kapazitätsanpassungen in einem Verkehrsunternehmen
4.1 Vorbemerkungen
4.2 Kapazitätsrelevante Produktionsfaktoren
4.3 Handlungszeitraum
4.4 Formen der Kapazitätsanpassung
4.5 Vergaberechtliche und vertragliche Rahmenbedingungen
4.6 Arbeitsrecht und Sozialvorschriften
4.7 Anforderungen durch System- und Fahrgastinformation
4.8 Inanspruchnahme von Reserven für kurzfristige Kapazitätsanpassungen
4.9 Steuerung der Fahrgastnachfrage
4.10 Resultierende Maßnahmen zur kurzfristigen Kapazitätsanpassung
5 Verfahren zur Ermittlung wetterabhängiger Nachfrageszenarien für die Kapazitätsplanung
5.1 Verfahrensaufbau und erforderliche Datengrundlage
5.2 Datenermittlung
5.3 Datenaufbereitung (Verfahrensstufe 1)
5.4 Ermittlung von Zusammenhängen zwischen Wetter und Nachfrage (Verfahrensstufe 2)
5.5 Ableitung kapazitätsrelevanter Szenarien (Verfahrensstufe 3)
6 Anwendungsbeispiel
6.1 Untersuchungsregion
6.2 Datengrundlage
6.3 Datenaufbereitung (Verfahrensstufe 1)
6.4 Ermittlung von Zusammenhängen zwischen Wetter und Nachfrage (Verfahrensstufe 2)
6.5 Ableitung kapazitätsrelevanter Szenarien (Verfahrensstufe 3)
6.6 Fazit zur Verfahrensanwendung
7 Zusammenfassung und Ausblick
7.1 Zusammenfassung
7.2 Ausblick
QUELLENVERZEICHNIS / The present work contains the development of a procedure for the consideration of weather-dependent demand scenarios in public transport. Using statistical methods and factual knowledge, the demand is first analysed with regard to its weather dependency. In this way, cases are identified in which the fluctuations in demand that have occurred so far were subject to weather dependency. Based on the results, both capacity-relevant and capacity-independent measures for improving service quality or the efficiency of resource utilization can be derived.
It will also be examined, whether the weather-dependency of demand requires a change in the supply of capacity, and whether these requirements can be met. The method was tested on the basis of demand data for five railroad lines of the Usedomer Bäderbahn. Detailed researches on the possibilities and limits of short-term capacity adjustments complement the development of the process.:GELEITWORT
ABSTRACT
TABELLENVERZEICHNIS
ABBILDUNGSVERZEICHNIS
BEGRIFFE UND ABKÜRZUNGEN
FORMELVERZEICHNIS
1 Motivation, Zielstellung und Aufbau der Arbeit
2 Wetterabhängigkeit der Verkehrsnachfrage
2.1 Verkehrsbedarf und Verkehrsnachfrage
2.2 Wetterabhängigkeit der Verkehrsnachfrage
2.3 Verkehrsnachfrage durch den Freizeitverkehr
2.4 Wetterabhängigkeit von Freizeitaktivitäten
2.5 Zusammenfassung zum Stand der Forschung in Bezug auf die Wetterabhängigkeit der Verkehrsnachfrage
3 Kapazitätsplanung als wesentliche Planungsaufgabe im ÖPNV
3.1 Begriff Kapazität
3.2 Aufgabe der Kapazitätsplanung im Handlungsumfeld des ÖPNV
3.3 Verantwortlichkeiten für die Kapazitätsplanung
3.4 Anspruchsgruppen gegenüber der Kapazitätsplanung
3.5 Einordnung der Kapazitätsplanung in die Abfolge der Planungsaufgaben bei der Erstellung von Verkehrsangeboten
3.6 Allgemeiner Prozessablauf bei der Kapazitätsplanung
3.7 Beschreibung der Nachfrage als Basis für die Kapazitätsplanung
3.8 Nachfrageunabhängige Einflussgrößen und Randbedingungen
3.9 Fahrtgenaue Kapazitätsdimensionierung je Betriebstag als Input weiterer Planungsschritte
3.10 Disposition von Fahrzeugen und Personal
3.11 Schlussfolgerungen für die Berücksichtigung wetterabhängiger Nachfrageschwankungen bei der Kapazitätsplanung
4 Möglichkeiten und Grenzen kurzfristiger Kapazitätsanpassungen in einem Verkehrsunternehmen
4.1 Vorbemerkungen
4.2 Kapazitätsrelevante Produktionsfaktoren
4.3 Handlungszeitraum
4.4 Formen der Kapazitätsanpassung
4.5 Vergaberechtliche und vertragliche Rahmenbedingungen
4.6 Arbeitsrecht und Sozialvorschriften
4.7 Anforderungen durch System- und Fahrgastinformation
4.8 Inanspruchnahme von Reserven für kurzfristige Kapazitätsanpassungen
4.9 Steuerung der Fahrgastnachfrage
4.10 Resultierende Maßnahmen zur kurzfristigen Kapazitätsanpassung
5 Verfahren zur Ermittlung wetterabhängiger Nachfrageszenarien für die Kapazitätsplanung
5.1 Verfahrensaufbau und erforderliche Datengrundlage
5.2 Datenermittlung
5.3 Datenaufbereitung (Verfahrensstufe 1)
5.4 Ermittlung von Zusammenhängen zwischen Wetter und Nachfrage (Verfahrensstufe 2)
5.5 Ableitung kapazitätsrelevanter Szenarien (Verfahrensstufe 3)
6 Anwendungsbeispiel
6.1 Untersuchungsregion
6.2 Datengrundlage
6.3 Datenaufbereitung (Verfahrensstufe 1)
6.4 Ermittlung von Zusammenhängen zwischen Wetter und Nachfrage (Verfahrensstufe 2)
6.5 Ableitung kapazitätsrelevanter Szenarien (Verfahrensstufe 3)
6.6 Fazit zur Verfahrensanwendung
7 Zusammenfassung und Ausblick
7.1 Zusammenfassung
7.2 Ausblick
QUELLENVERZEICHNIS
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Electricity price dynamics in Sweden : Regression analysis of factors influencing electricity pricingAhmed, Ali, Lisa, Jonsson, Naima, Ahmed January 2024 (has links)
This thesis examines the relationship between weather variables (wind speeds and temperature), fossil fuel prices (natural gas and coal), and electricity prices in Sweden's electricity market from 2013 to 2023. This research employs multiple linear regression to quantitatively analyze how weather variables and fossil fuel prices influence electricity prices across Sweden's four electricity price areas (SE1, SE2, SE3, and SE4). The study utilized electricity price data from Nord Pool, meteorological data from the Swedish Meteorological and Hydrological Institute, and energy commodity price data from the International Monetary Fund. The findings reveal that wind speeds have a negative correlation with electricity prices in each electricity price area analyzed. Similarly, temperature also exhibits a negative correlation with electricity prices. In contrast, natural gas and coal prices show a positive correlation with electricity prices. The explanatory power of natural gas and coal prices is higher compared to weather variables; however, this influence diminishes in the northern electricity price areas. Addressing gaps in existing research, this thesis enhances the understanding of the energy market amid the transition towards more sustainable energy systems. The findings have implications for policy formulation and market strategy, particularly in enhancing energy security and sustainability in Sweden. Additionally, this study explores the merit order effect, emphasizing how renewable energy integration influences electricity market volatility and pricing. By providing a comprehensive analysis of these factors, this research offers valuable insights for stakeholders aiming to navigate and optimize the evolving landscape of Sweden's electricity market.
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