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This thesis aims to investigate the differences in diurnal and annual use of districtheating for two kind of heat users with different amount of warm water usage. Thefirst user is a hotel including spa facilities that uses a large amount of warm water, thesecond user is an office building that has a very low usage of warm water.The aim is to develop and validate methods for forecasting district heat use onvarious timescales. The average daily temperature for each month is shown to benormally distributed and average temperatures are therefore suitable for long-termforecasting. It is also shown that there is a clear linear relationship between lowerout-door temperature and higher use of district heating power. The thesis shows thatthe hotel will have a different power signature for their district heating compared tothe office that use a relative low amount of warm water.Short term forecasts, with a horizon of 10 days, are made for both the hotel andoffice building. As a result of the forecasts it is shown that the it is easier todetermine when the peak district heating power outtake will occur for the buildingwith a high amount of domestic hot water usage. However, forecasts for total diurnalheat use are equally accurate for the investigated buildings

Increased use of variable energy and integration of electricity markets in the European Union have led to new challenges when balancing supply and demand in the grid. Load management is a possible way to manage these challenges by adjusting electricity consumption in order to balance the power system. Household appliances can be used for this purpose, for example by providing automatic frequency control. The aim of this master thesis is to investigate the potential of load management from private households and to examine how the power system is affected by a more flexible electricity consumption. The thesis focuses on fridges as automatic frequency control reserves and the ability of fridges to balance the power system. Attributes such as capacity, activation time, persistence and the effect of load reconnection has been modelled in Simulink, Matlab. Complementary interviews with actors from the electricity industry have been done to summarize their insights on demand response. The results indicate that fridges can be used as a part of the automatic frequency controlled reserve FCR-N, based on assumptions made in this study. However, current requirements imposed on balancing resources are not fully met by the fridges. In order for household appliances to provide the needed flexibility, some requirements might need to be rephrased. The results also show that the capacity for providing balancing services differs for positive and negative imbalances, as consumption can be reduced with 30 MW and increased with 66 MW. When controlling the fridges by moving the reference temperature, there is a risk that the appliances will synchronize with each other, i.e. reconnect or disconnect at the same time, resulting in frequency oscillations. It is therefore important that load management is designed to avoid this kind of behavior.

Small scale biogas plants (max digester volume 1000 m3) in Sweden produced in average 1.26 GWh per plant in 2014. Most of the biogas was used for combined heat and power production. The relatively cheap electricity in Sweden makes this a low profit business. If the biogas is upgraded to vehicle fuel its value will increase. However, upgrading biogas with conventional methods is costly, and for small scale biogas plants this cost cannot be justified. Development of alternative upgrading methods is an option to decrease the cost of upgrading and making small scale vehicle fuel production a reality. In this master thesis the upgrading method known as in-situ methane enrichment was investigated. This method involves desorption of carbon dioxide in the sludge using a desorption chamber separated from the digester. Air is blown through the sludge for desorption of carbon dioxide. Subsequently, the sludge is pumped back to the digester. The aim was to perform an energy mapping on the enrichment facility installed at the biogas plant (260 m3) at Sötåsens naturbruksgymnasium. In addition, the possibility to absorb ammonium-nitrogen in the off-gas from the process using a scrubber was also investigated in laboratory-scale. The results showed that the upgrading facility lost large quantities of heat during operation. During the coldest circumstances using an air flow of 260 m3/h through the sludge, the heat loss was 495 kWh/day. The corresponding efficiency of carbon dioxide removal was 7.6 kWh/m3 removed carbon dioxide. With proper insulation and heat recovery, the facility has the potential to decrease the heat demand to ca 139 kWh/day, giving an efficiency of 2.3 kWh/m3 removed carbon dioxide. The electric efficiency was 1 kWh/m3 removedcarbon dioxide. The laboratory test of ammonium-nitrogen absorption indicated that the plant has a potential to absorb 59 – 275 kg nitrogen/year by installing a scrubber with a volume of 122 l. The economic benefits are small, but other values such as reduced ammonia pollution or heat recovery solutions using a scrubber should be considered. Biogas 2020

The demand for biogas as vehicle fuel has risen sharply and there is a great need for increased production. A possible addition of vehicle gas can be produced by upgrading landfill gas which is formed by degradation of organic waste. This thesis investigates the potential of producing vehicle fuel from landfill gas in the region of Biogas Öst. In 2008, an amount of 32 million Nm3 landfill gas was extracted in the region. This level can be maintained for another ten years if the efficiency of gas extraction is improved. The annual production will decrease with time since landfills aren’t allowed to receive more organic waste. Landfill gas is hence a large but not lasting source of vehicle fuel. The amount of available landfill gas that is possible to upgrade to vehicle gas is limited by technical and financial issues. With certain limitations taken into account, an estimation of the regions potential gives an annual production of 8.2 million Nm3 vehicle gas. This means that more than 7 000 private cars or 250 buses could be operated with vehicle fuel from landfills in the region.

Riksbyggen, one of Sweden’s largest real estate companies, are planning to build a new residential area outside Uppsala, Sweden. Adjacent to the houses in the area, Riksbyggen are considering installing a 137 kWp photovoltaic (PV) system to supply the residents with renewable energy. In the first part of this study, the proposed PV system is analyzed based on benefits and profitability for the residents, using the software HOMER. Possibilities for including 3 kWp roof-mounted PV systems with varying azimuth as a complement to the larger system are evaluated. In the second part, options for implementing an Energy Management System (EMS) with battery storage or load shifting in the distribution grid using MATLAB. The system uses forecasting of PV generation, electricity prices and electricity demand to optimize the system control strategies. The results from the study indicate that installation of the 137 kWp PV system could lead to reduced average electricity costs of 21,1 % for the residents. If the system is completed with roof-mounted PV modules of varying azimuth for 12 % of the households in the area, the average electricity cost is reduced by 29,4 %in total. Implementing an EMS with energy storage in the distribution grid was not found to be an economically viable option, mainly due to high energy storage costs. The system control strategies can be improved by using forecasting. The economic benefits of load shifting for a single household were found to be too low to give incentive for system investment.

Under de senaste åren har det skett en mycket snabb utbyggnad av solenergi i bebyggelsen i många länder, initialt i europeiska länder som Tyskland, Italien och Spanien men idag sker en snabb utveckling i de flesta länder i världen. I Sverige har användningen av solenergi tagit fart lite senare än i de södra grannländerna, mycket på grund av låga elkostnader från vatten- och kärnkraft. I samband med att investeringsstöd för solceller introducerades 2009 har dock solcellsmarknaden tagit fart om än från en låg nivå (se Figur 1). Från att solenergi framförallt nyttjats för uppvärmning eller för elgenerering vid fritidshuset eller båten sker nu installeringar av solcellsystem på framförallt villatak och lokaler i Sverige.För att möta både internationella såväl som lokala målsättningar att minskaklimatpåverkan är det viktigt att få en bild av potentialen för olika typer av förnybar energitillförsel. Den här studien är genomförd på uppdrag av Länsstyrelsen i Skåne med syfte att bedöma potentialen för solenergi på takytor inom hela länet, men även uppdelat på kommunnivå, både i närtid och med en längre tidshorisont. Utifrån trenden med sjunkande priser på solceller har potentialen för solvärme bedömts mycket liten, men kan delvis vara intressant för småhus.Potentialberäkningarna utgår från byggnadsbeståndet i fastighetskartan, uppdelat på olika byggnadstyper, där kvalificerade antaganden gjorts för vilken grad takytor för olika byggnadstyper kan utnyttjas för solenergi.Resultaten visar att det finns ungefär 105 km2 tillgänglig takyta för solenergi. Den realiserbara potentialen bedöms vara 3.1 TWh i scenario A samt 7.5 TWh i scenario B. Detta kan jämföras med elkonsumtionen i Skåne län som uppgick till 12.1 TWh 2014.

The inability to achieve sufficient reduction of greenhouse gas emissions has led to the development of techniques with potential to achieve negative greenhouse gas emissions. One of these techniques is called Bio-energy with carbon capture and storage (BECCS), where carbon dioxide is captured from biogenic point sources with biogenic emissions and stored underground. Biochar applied to farmland is another technique with potential to achieve negative greenhouse gas emissions. Both Swedish and international strategies, to meet the obligations in the Paris Agreement, include negative greenhouse gas emissions. A life cycle approach is required to ensure that the techniques deliver on the promise of negative emissions. A Life cycle assessment was conducted where the global warming potential was calculated for BECCS and biochar added to farmland in two different scenarios where tops and branches (GROT) from the Swedish forest industry were used as feedstock. The techniques were compared to a reference scenario where GROT were used in a combined heat and power plant (CHP-plant). The results show that BECCS has the potential to achieve net negative emissions of between -168 and -666 kg CO2-equivalents/ tonne GROT dry matter (DM). When GROT is harvested from 80% of the yearly final felling areas in Sweden and combined with thinning, 666 kg CO2-equivalents/ Mg GROT DM is equivalent to in 4,4 million ton CO2-equivalents per year. This corresponds to 25,8 % of Sweden's greenhouse gas emissions from domestic transportation in 2016. The results of greenhouse gas emissions from biochar applied to farmland varied between 934 to -344 CO2-equivalents/ Mg GROT DM. When GROT is harvested from 80% of final felling areas in Sweden and combined with thinning, -344 CO2-equivalents/ Mg GROT DM is equivalent to 2,2 million ton CO2- equivalents per year. This corresponds to 13,3 % of Sweden's greenhouse gas emissions from domestic transportation in 2016. Both techniques have the potential to achieve net negative greenhouse gas emissions. However, the results are greatly influenced by the climate impact from generating the electricity to replace the losses in electricity production when GROT is used for BECCS and biochar instead of in a CHP-plant. Oförmåga att minska utsläppen av växthusgaser i tillräckligt takt för att undvika en alltför kraftig global uppvärmning har motiverat framtagandet av tekniker med potential att minska mängden koldioxid i atmosfären. En av dessa tekniker är bioenergi med koldioxidlagring (Bio-energy with carbon capture and storage, BECCS), där koldioxid avskiljs från punktkällor med biogena utsläpp och lagras i geologiska strukturer. Även biokol tillsatt till jordbruksmark har potential att bidra till negativa utsläpp. Både svenska och internationella strategier inkluderar negativa utsläpp för att uppfylla förpliktelserna i Parisavtalet. För att säkerhetsställa att teknikerna lever upp till potentialen krävs ett livscykelperspektiv där klimatpåverkan beräknas på systemnivå. En livscykelanalys utfördes, där klimatpåverkan vid utnyttjande av grenar och toppar (GROT) från den svenska skogsindustrin beräknades för teknikerna BECCS och biokol tillsatt till jordbruksmark. Teknikerna jämfördes med ett referensscenario där GROT förbränns i ett kraftvärmeverk för att producera el och fjärrvärme utan omhändertagande av koldioxid som bildas vid förbränning. Resultaten visar att BECCS har potentialen att bidra med negativa utsläpp på mellan -168 och -666 kg CO2-ekvivalenter/ ton GROT torrsubstans (TS). Då GROT-skörden ökar till 80% av den årliga avverkade arealen skog i Sverige och kombineras med gallring, resulterar 666 kg CO2-ekvivalenter/ ton GROT TS, i 4,4 miljoner ton CO2-ekvivalenter per år. Detta motsvarar 25,8 % av klimatpåverkan från inrikestransporter i Sverige år 2016. Nettoutsläppen från biokol tillsatt till jordbruksmarker, varierar mellan 934 och -344 kg CO2-ekvivalenter/ ton GROT TS. Då GROT-skörden ökar till 80% av den avverkade arealen skog i Sverige och kombineras med gallring, resulterar 344 kg CO2-ekvivalenter/ton GROT TS i 2,2 miljoner ton CO2-ekvivalenter. Detta motsvarar 13,3 % av klimatpåverkan från inrikes transporter i Sverige år 2016. Båda teknikerna har potential att åstadkomma nettonegativa växthusgasutsläpp, men resultaten är beroende av klimatpåverkan från ersättande el- och fjärrvärmeproduktion.

Electricity production from renewable energy resources such as wind energy and photovoltaics is variable. Integration of these intermittent resources into the electricity system leads to new challenges in how to manage imbalance between supply and demand on the grid. One way to meet these challenges is to develop so-called smart grid solutions. One idea, called demand response, is to adjust the amount or timing of energy consumption, e.g. by control of household appliances, to provide flexibility that could be used to balance the grid. In aggregate, when applied to many units across the system, large volumes of energy could be made available when needed and this grid flexibility can be used as a product on the electricity regulation market. Despite the potential benefits, the number of demand response bids is currently low. The aim of this thesis is to identify barriers in the Swedish regulation market, and togive Sweden's transmission system operator, Svenska kraftnät, recommendations on how to facilitate implementations of the technique. This has been done throughliterature studies and a wide range of interviews with people within the electricity market sector. The results indicate that a combination of several elements in the complex energy system impede the introduction of demand response. The main issues are related to market regulations and profitability difficulties. The authors recommend that Svenska kraftnät lowers the minimum bid size in all of the Swedish bidding areas, and adjusts the balance responsibility agreement and the system of balancing settlement.

In recent years, the enthalpy raise hot channel factor limit has decreased significantly due to the power upgrade of Ringhals 4 and the use of shielding fuel assemblies. The shielding fuel assemblies task are to reduce the neutron leakage to the reactor vessel and in that way extend the reactor lifetime. This is achieved by replacing a few fuel rods with steel rods. Experiences from the last fuel cycles show that the core design procedure has been hampered because of this and that it’s hard to stay under the design limit. A way to overcome this problem and to improve the fuel economy is to introduce the use of radial enrichment distribution in the fuel assembly. This master thesis shows, through a case study of three fuel cycles at Ringhals 4, that the internal peaking factor can be improved by roughly 2–3 % and that the maximum enthalpy raise hot channel factor can be improved by about 2.0–2.5 % if the fuel assemblies contain three different levels of enrichments instead of currently one. This can be achieved without any noticeable decrease in cycle length. Genom en fallstudie av tre driftcykler för Ringhals 4 visar den här rapporten att max FΔH under cykeln kan sänkas med 2,0–2,5 % om bränsleknippena radiellt anrikningsoptimeras med minst tre delanrikningar. Totalt under cykeln kan FΔH sänkas med upp till 4 %. Om radiell anrikningsoptimering införs för Vattenfalls PWR:er skulle arbetet med att designa härdarna förenklas och utrymme ges för att ladda reaktorerna på ett mer ekonomiskt sätt.