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The Global ETD Search service is a free service for researchers
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Showing 1 to 8 of 8 (0.059 seconds)Spelling suggestions: "subject:"dialektutjämning"" "subject:"resultatutjämning""
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Nyttan av en dynamisk framledningstemperatur i fjärrvärmesystem : Effekt- och flödesutjämnande körstrategier som tar hänsyn till dygnets varierande värmebehov / The Benefits of a Dynamic Supply Temperature in District Heating Systems : Power and Flow Equalising Control Strategies That Responds to Daily Variations in Heat DemandLindgren, Oskar, Hellsberg, Richard January 2016 (has links)
The heat demand in a city varies a lot over the course of the day because of the outside temperature and social behaviour. The heat demand is at its peak in the mornings when people wake up and are active while it is still cold outside. A common way of fulfilling the heat demand is to use district heating, which uses heated water which is pumped out to costumers, where the delivered energy is used for heating buildings and tap water. A common way of regulating the produced power is to manually adapt the supply temperature to the coldest outside temperature of the day and then let the water flow handle the variations in heat demand. This also leads to variations in the produced power that corresponds to the heat demand. The focus of the master thesis has been to examine the benefits of using a dynamic supply temperature that changes over the course of the day. Two different strategies has been developed with the purpose of equalising the flow and the produced power, to ensure a reliable distribution and to reduce the production costs. Both of the strategies focus on sending out warmer water in advance to peaks in the heat demand while sending out colder water in advance to the troughs in the heat demand, where the foresight needed is a result of the time delay of the system. Besides the actual equalisation of the power and flow, both strategies can result in increases in profit from electricity production, reduced pump costs and lowered emissions. The profit of the power and flow equalising strategies have been evaluated for the district heating system in Linköping between October 2014 and September 2015. The strategies have been evaluated in different cases, both a standard case which is kept within the limits of the district heating system, and also cases where these limits have been stretched. The results of the standard case shows that both strategies increases the electricity production, where the flow equalising strategy can increase the profits from electricity production with approximately 240 000 SEK per year and the power equalising strategy can increase the profits from electricity production with approximately 370 000 SEK per year. The flow equalising strategy leads to both power and flow equalisation. The power equalising strategy provides a better power equalisation compared to the flow equalising strategy but in return leads to large flow variations. For the cases where the limits are stretched, the power and flow equalisation can be additionally improved, which strongly affects the economic results. A more even water flow and supplied heat power is beneficial to the production but their effects are hard to measure economically.
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Svänghjul som lastutjämningOdin, Håkan January 2020 (has links)
Denna rapport visar på problemen i det svenska elnätet som uppstår på grund av de intermittenta energikällorna som ökar i antal vilket medför en stor variation i tillskott av energi till elnätet. Detta har gjort att el- och nätbolagen står inför stora utmaningar med möjlig kapacitetsbrist i vissa områden i framtiden samt risken för effektbrist i nätet vid vissa tidpunkter. Det har i sin tur lett till att elpriser varierar mer över dygnet och kostnaden för elleveranser ökar. En möjlig lösning på detta problem är energilagring hos elnätbolagens kunder där svänghjulstekniken är en av flera möjligheter med miljömässiga fördelar i förhållande till andra tekniker. I Jämtkrafts elnät är dock denna möjlighet inte kostnadseffektiv i dagsläget då effektpriset är lågt och elpriset inte varierar nog kraftigt, samtidigt som svänghjulstekniken för långtidslagring av energi är ny och under utveckling. Vid denna typ av energilagring är det viktigt att energibehovet stämmer överens med priset på elmarknaden för att nyttja maximal möjlighet till arbitrage och samtidigt minska effekttoppar i största möjliga mån. Studien visar på svårigheten att få energilagringen lönsam på grund av förluster i lagringen samtidigt som andra lösningar på effektutjämning kan vara mer lönsamma i vissa fall.
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Undersökning av kombinerade lönsamhetsstrategier för ett batterilager / Analysis of combining profitability strategies to increase profitability of a battery storageBouveng Sellin, Alexander January 2022 (has links)
The increasing electricity production from intermittent energy sources creates both challenges and possibilities in the future energy system. When the controllability in the production of electricity deteriorates, the flexibility of the electricity consumption must increase for the energy system to work. The study examines the possibilities for the profitability strategies load smoothing, peak shaving, participation on the flexibility market and its combinations to reduce the electricity bill for Vasakronan’s office building at Sperlingens Backe 47 in Stockholm using a nickel-metal hydride (NiMH) battery storage. The results indicated participation on the flexibilitymarket to be the most profitable strategy although none of the strategies nor their combinations managed to reduce the electricity bill of the office building. For an installation of a NiMH battery in the office building to become profitable, the price of NiMH batteries must decrease by approximately 80 %.
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Effektutjämning av Fjärrvärmelast genom att utnyttja Byggnaders Värmetröghet : En simuleringsstudie / Heat Load Balancing of District Heat Load by Using Thermal Inertia of Buildings : A simulation studyHagman, Ida January 2024 (has links)
This thesis explores the potential of using building thermal inertia for thermal load balancing. It focuses on calculating time constants and determining the duration and amount of load that can be decreased in the building without the indoor temperature being decreased more than 0.5 degrees. Using data on residential area, construction year, building material, and supplied heat load, the study addresses the following main questions: calculating time constants for selected buildings, the quantities of supplied heat load that can be decreased, and over what duration of time, for the studied buildings.The method consisted of mapping a large amount of buildings from construction year, building material and relative heat demand to make a selection of buildings that were common and can be representative for more buildings. For each selected building the time constants and duration times were calculated. A model for heat load demand for space heating was made for each selected building to calculate the effect available for heat load balancing.Buildings with larger residential areas, higher heat demands per building, and lower heat demand per square meter exhibit significant potential for heat load balancing. The study identifies a newly constructed building with concrete structure and facade as having the highest thermal inertia. There is also potential for heat load balancing in larger, energy-efficient brick-built buildings.
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Flexibilitetsresurser för effektutjämning vid Brunna butikslager : En studie av samverkan mellan solenergi, energilager och smart laddning av en elektrifierad fordonsflottaBergkvist, David January 2023 (has links)
Due to the ongoing climate crisis there is a need for a transition of energy usage. The transition is dependent on electricity as an energy carrier which puts pressure on the electricity grid to develop at the same rate as the electricity demand increases. However, the process of building new transmission lines is expensive and drawn out. By adjusting the demand side of power usage with flexibility resources, it is possible to lower the peak power usage. This both reduces the risk of congestion on the electricity grid as well as lower the costs for the user. This report investigates how energy storage and smart charging of electric vehicles can synergize with solar electricity production to reduce the monthly peak power usage at Brunna distribution center. A peak shaving energy management system (EMS) is created and put in a simulation of four different scenarios of the system. The scenarios consist of two different sizes of the electric vehicle fleet and solar electricity production. The capacity of the energy storage is varied in each scenario. The results show that the flexible charging of the vehicle fleet can lower the monthly peak power consumption by 10-32 % depending on which month and scenario, with energy storage it decreased even further in three out of four cases. With the largest investigated energy storage the monthly peak power consumption could be reduced with 14-44 % depending on which month and scenario. For the scenarios with a small vehicle fleet the yearly peak power consumption decreased with an increasing energy storage capacity. The monthly peak power consumption decreased most in the summer and especially if there was more solar electricity production. For the scenarios with a large vehicle fleet, the yearly peak power consumption did not decrease with increasing capacity of the energy storage. For the monthly peak power consumption to lower, a steady production of solar electricity was needed. With the smaller vehicle fleet an energy storage can be useful to lower the monthly peak power consumption all year around. However, in the scenarios with a larger fleet the smart charging is sufficient to lower the peak power consumption to a level which needs more electricity generation for it to reduce further. In this case the energy storage is primarily used to save excess solar energy from the day to the evening. Saving solar energy for later increases the self-consumption and self-sufficiency in the system. More solar electricity production and more flexibility resources results in a system less reliant on the electricity grid.
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Batterilagring För Södra Hallands Kraft : Nyttor Och PotentialAhlgren, Alma January 2024 (has links)
With the goal of achieving 100% fossil-free electricity production by 2040 in Sweden, the electricity system is expected to undergo significant changes due to increased electrification, digitalization, and automation. Battery storage will become crucial for supporting and stabilizing the power grid, as well as balancing demand and production, which reduces the risk of overload. It also contributes to increased grid flexibility and a smoother, more efficient use of the power network. The purpose of this work is to develop a deeper understanding of battery storage technology and its potential impact on the Swedish power grid to meet current and future energy needs. The method examines the energy usage patterns of Södra Hallands Kraft to appropriately size a battery storage system and determine its operational scenario. It is essential to consider both the battery’s power (W), which describes the total amount of power that can be delivered, and storage capacity (Wh), which describes the total amount of energy that can be stored. By implementing battery storage systems, the share of renewable energy usage can increase, and dependence on external energy sources can decrease. This work examines different threshold levels: 60 MW, which requires a 33 MW/ 735 MWh battery; 65 MW, which requires a 28 MW/ 414 MWh battery; and 70 MW, which requires a 23 MW/ 153 MWh battery. These thresholds successfully reduce all power peaks between 2019 and 2023. This also leads to significant economic savings in the form of reduced grid fees. / Med målet att uppnå 100% fossilfri elproduktion till år 2040 i Sverige, förväntas elsystemet genomgå betydande förändringar på grund av ökad elektrifiering, digitalisering och automatisering. Batterilager blir viktiga för att stödja och stabilisera elnätet, samt balansera efterfrågan och produktion som minskar risken för överbelastning. Det bidrar även till en ökad flexibilitet på elnätet och en jämnare och mer effektiv användning av elnätet. Syftet med arbetet är att utveckla en djupare förståelse för batterilagringsteknik och dess potentiella påverkan på det svenska elnätet för att möta dagens och framtidens energibehov. Metoden undersöker energianvändningsmönstren för Södra Hallands Kraft, för att kunna dimensionera ett batterilager med lämplig storlek och driftscenario. Det är därför viktigt att beakta både batteriets effekt (W), som beskriver den totala mängd effekt som kan levereras, och lagringskapaciteten (Wh), som beskriver den totala mängd energi som kan lagras. Genom att implementera batterilagringssystem kan andelen förnybar energianvändning öka och beroendet av externa energikällor minska. Arbetet undersöker olika tröskelnivåer på 60 MW som kräver ett batteri på 33 MW/ 735 MWh, 65 MW som kräver ett batteri på 28 MW/ 414 MWh, samt 70 MW som kräver ett batteri på 23 MW/ 153 MWh. De lyckas minska alla effekttoppar mellan 2019 – 2023. Detta bidrar även till betydande ekonomiska besparingar i form av minskade elnätsavgifter.
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Tillämpning av batterilager som energitjänsten lastutjämnare : En studie om batterilagring för en medelstor abonnent i Varberg Energis elnät / Application of battery energy storage as smoothening of power fluctuationAl-imarah, Amena, Stenberg, Elin January 2016 (has links)
Arbetet Tillämpning av batterilager som energitjänsten lastutjämnare är en litteraturstudie och en kvantitativ studie. I studien har driftkarakteristiken år 2015 hos en matvarubutik legat till grunden. Arbetet har syftat i att besvara frågan kring ett batterilagers lämplighet som agerade för lastutjämning. För att ta reda på det har batterilagersegenskaper kartlagts och dimensionering gjorts utifrån två olika driftfall. En ekonomisk besparingspotential har även beräknats utifrån de bägge driftfallen. Driftfallen har valts att kallas teknisk dimensionering och ekonomisk dimensionering. De tekniska dimensionerade lagerna har en lager storlek om 617 kWh och 555kWh vilket motsvarar 7,1% respektive 5,8% av den dagliga energianvändningen. För de ekonomiskt dimensionerade lagerna har en lager storlek om 597 kWh och 233kWh vilket motsvarar 6,8% respektive 2,8% av den dagliga energianvändningen. Den ekonomiska besparingspotentialen blir som störst för en blandad körning av de bägge driftfallen. Trotts att besparingspotentialen är uppskattade under ideala förhållanden med varken förluster eller degraderad prestanda lönar det inte sig att investera i ett batterilager för att enbart utföra tjänsten effektutjämning idag. Investering i ett batterilager för effektutjämning har potential att bli lönsam först när den kan tillgodose fler energitjänster eller när alternativkostnaden är förhöjd. / This thesis, is a study of battery energy storage and its use as energy source and smoothening of power fluctuation. Studies have been made as a systematic review and a quantitative study. The study has consisted of analysing the power characteristic from a supermarket in the city of Varberg during year 2015. The object has been to evaluate the energy storage and the power smoothing qualities. Therefore the battery energy storages characteristics have been evaluated in this systematic review. For the quantitative study, calculations of the energy storage sizes were made for two separate operation modes. The two different operation modes were named technical dimensioning and economic dimensioning. The function of the technical dimensioning was to smooth the power outlet from the grid, while the function of the economic dimensioning was to enable the supermarket to buy more energy during low-price hours. Based on monthly power characteristics, each dimensioning gave as a result two energy storage possibilities, one in medium and one in small size. The technical dimensioning resulted in battery energy storage of the sizes 617 kWh and 555kWh which is comparable to 7,1% and 5,8% of the daily energy usage of the supermarket. The economic dimensioning resulted in battery energy storage of the sizes 597 kWh and 233kWh which is comparable to 6,8% and 2,8% of the daily energy usage of the supermarket. For optimizing the economic savings, a variation of technical and economic operation mode are needed, depending on calculated power usage through the day and elspot prices. The study shows that a battery storage is difficult to finance. The calculated economic savings were estimated during ideal conditions and without power loss or loss in performance. As a conclusion from this study a battery storage may have a good payback if there are several energy services to be filled.
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Förnybar energi på SvalbardAndreasson, Tobias, Lindh, Emelia January 2018 (has links)
This degree thesis investigates the possibilities of producing food inside a container at Svalbard, using renewable energy and energy storage. The idea was to be able to place the container at remote places without the need of being connected to the grid. We chose Svalbard, where it is cold and the sun is shining 24 hours a day at summertime. In the winter the opposite occurs and the sun is absent from the sky. The work is divided into theoretical studies and results based on different calculations. Such as economical evaluations (LCOE), and simulations using the computer programs Matlab and PVsyst. We have investigated if solar power and wind power is suitable as energy sources. Options for storage were batteries, grid and hydrogen storage. Different cases with Photovoltaics- and wind power plants, with batteries or grid, were compared against each other. It is not possible to use the grid as storage. This resulted in different sizing of our cases, with no excess energy production. The result showed that a 5 kWp photvoltaic plant with dual axis tracking system, was the most profitable. The Pay off would be 14 years and the total profit 63 453 SEK. If it will become possible in the future to use the grid at Svalbard as storage, it will open up opportunites for bigger systems. This will lead to higher profit than with smaller ones. Our results show that it is now most profitable with solar power.
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