Introduction: Villas built before 1960 make up about 45% of the housing stock in Sweden. With the average U-value of their walls around 0.5 W/(m²·K), and the average U-value for a horizontal attic floor in single-family houses is 0.33 W/(m²·K), there is significant concern about improving these values. Sweden's energy and climate goals aim for a 50% improv in energy efficiency by 2030 compared to 2005. Purpose: The purpose of this project is to explore potential energy efficiency measures for an older single-family house built in 1953. Specifically, the goal is to align the heat transfer coefficient of individual building components with the requirements outlined in BBR when modifying the building envelope. By doing so, the authors aim to contribute to and encourage the renovation of existing villas, which can lead to reduced energy usage. Moisture control, cost considerations, and examining insulation proposals for the Slab on grade are not included in this study. Method: This work is based on a case study of a single-family house from 1953 located in Ale, Västra Götaland in Sweden. The research uses a hybrid approach that integrates bothquantitative and qualitative methods to comprehensively investigate energy efficiency in older single-family houses. Quantitative methods include numerical measurements such as U-value calculations and heat demand analysis, while qualitative methods involve expert discussions on insulation requirements and heating system improvements. The methodology includes interviews to gain a deeper understanding of existing conditions and to propose ways to utilize the materials currently available on the market. It encompasses case studies and material analysis, with key calculations including U-value determination, average heat transfer coefficient (Um), and primary energy demand (EPpet). Energy-saving measures such as additional insulation and ventilation upgrades are central to the methodology, along with TMF calculations for heating system transitions. The method is consistently guided by predefined research questions to ensure coherence and clarity in the investigative process. Results: The study revealed that the original exterior wall of the case study had a U-value of 0.54 W/m²K, much higher than the current recommended value of 0.18 W/(m²·K), and the average U-value for a horizontal attic floor is 0.33 W/(m²·K) much higher than the current recommended value of 0.13 W/(m²·K). Through renovation, U-values of 0.17 W/(m²·K) for exterior walls and 0.1 W/(m²·K) for the ceiling were achieved. Option F, the best proposal, included a ground-source heatpump with an inverter, mechanical exhaust ventilation, and various insulation improvements, leading to energy savings of approximately 36 MWh/year. The average heat transfer coefficient (Um-value) of 0.29 W/(m²·K) was below the recommended 0.30W/m²K. Option F resulted in an energy classification of B. The improved EPpet value for Option F was 52 kWh/m², well below the recommended 90 kWh/m². Simply adding insulation to walls and roofs and upgrading windows yields slightly better results than only replacing the heating system.

It is essential that all sectors quickly adapt to the upcoming challenges of climate change and the new energy landscape, characterized by an increased use of renewable energy. Given that the heating sector constitutes a significant part of our total energy consumption, it faces a particular need to adapt to both stricter emission regulations and the growing integration of renewable energy sources within the energy system. This study focused on how a cogeneration company could take advantage of various technological innovations to adapt to the demands of the future. Through sensitivity analysis and mixed-integer linear programming (MILP) optimization, it proves that heat pumps and the combination of Carbon Capture and Storage (CCS) technology and Thermal Energy Storage (TES) are reliable and profitable investments to improve the flexibility and cost effectiveness of volatile energy systems, especially when electricity prices are low. In conclusion, both TES and heat pumps contribute to good system flexibility in cogeneration plants, which is important to meet the needs and challenges of the future.

<p>This thesis will discuss a novel method of tracking the Sun. An essential aspect of the method is to rotate a polar aligned single axis tracker such that the angle between the direction of the Sun and the normal of the module remains at a constant angle of 23.44 degrees or a few degrees more. The rotational symmetry that arises from this circumstance enables seasonal tracking to occur inside the module whilst maintaining efficient concentration. Several possible optical designs and a preferred optical design are presented as a way of implementing the tracking method. The tracking method is also open to a plethora of different concentrator photovoltaic system designs which may be integrated onto rooftops more effectively than conventional dual axis tracking systems.</p> / Master of Applied Science (MASc)

The global market of solar energy systems is currently experiencing a rapid growth, driven bythe increasing demand for renewable energy. To monitor the rapid expansion of solar energy, aerial imagery combined with deep machine learning can be utilized. This study aims to assess the market penetration and remaining potential for roof-mounted  decentralized solar energy across various market segments using these advanced technologies. Furthermore, the purpose is to assess the impact of socio-economic factors on the adoption of solar energy systems. The findings reveal that the photovoltaic system penetration rates are generally consistent across all the studied distributed market segments in Sweden, with a slightly higher rate for public buildings. The penetration of solar thermal systems is lower in comparison and are most common among single-family dwellings. Significant potential remains for rooftop solar installations, with 64.1% of roof area available and suitable for solar energy. Regarding the number of buildings, 76.9% of all buildings either lack or can enlarge an already existing solar energy system. The remaining potential across the market segments varies slightly due to different proportions of areas that are unsuitable for solar energy. The penetration rates are highest in central city areas, but with just slightly lower rates in urban and rural areas. Socio-economic factors such as educational level, employment rate, median income, and the proportion of people aged 65+ are shown to influence solar energy adoption.

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Snow-free surfaces is needed for parking place, platform, and playground and even in city center square. With energy prices rising, energy saving is becoming a hot topic. Meanwhile environmental problems are becoming more and more serious, thus, the ways to saving energy is becoming an eye-catcher. So burring heating pipes underground has been a popular way to get ice-free surfaces. Using heating pipes for melting snow is much more efficient and more benefit for the environment comparing with using other methods.   In this project, an energy analysis of a football pitch with an area of 5000 m2 is carried out under a series of conditions between insulated and uninsulated construction. All calculations are done with the so-called finite element method (FEM), in the COMSOL. COMSOL is used for simulating and calculating the energy use with outdoor temperatures of -5 ºC and -10 ºC. Top layer materials concrete, grass and stone are also discussed. The ability of XPS and EPS insulation material is compared and noted. The models are divided into two parts, one is with snowfall and the other is without snowfall.   The results in the report shows that adding insulation under the heating pipe has significant energy saving potential. The surface with concrete layer has the best insulated ability, which can prevent more heat losses. The EPS insulated construction has a better performance in keeping more heat in the soil.

abstract: The government support towards green energy sources for the better future of the planet has changed the perspective of the people towards the usage of green energy. Among renewables, solar is one of the important and easily accessible resources to convert energy from the sun directly into electricity and this system has gained fame since the past three decades. SRP has set up a 6.36 kW PV and 19.4 kWh battery system on the rooftop of Engineering Research Center (ERC). The system is grid-connected and ASU (Arizona State University) has developed two load banks with a minimum step of 72 watts to simulate different residential load profiles and perform other research objectives. A customer benefit analysis is performed for residential customers with photovoltaic (PV) systems and energy storage particularly in the state of Arizona. By optimizing the use of energy storage device, the algorithm aims at maximizing the profit and minimizing utility bills in accordance with the demand charge algorithm of the local utility. This part of the research has been published as a conference paper in IEEE PES General Meeting 2017. A transient test is performed on the PV-battery during the on-grid mode and the off-grid mode to study the system behaviour during the transients. An algorithm is developed by the ASU research team to minimize the demand charge tariff for the residential customers. A statistical analysis is performed on the data collected from the system using a MATLAB algorithm. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2017

This study was carried out on behalf of Pite Energi with the guidance of Rejlers. The assignment was to develop a simulation model over part of Pite Energi's power grid. This will allow calculations of losses and capacity limits in the network, which then can form the basis for future efficiency improvements. The work has also investigated the possibility of a backup line for the voltage level of 40 kV and how the energy losses are affected under the periods of high and low load in the 10 kV grid, respectively. The grid is constructed with two 40 kV lines, ordinary and reserve, which are parallel to each other. The voltage in these lines is transformed down to two different voltage levels of 10 and 20 kV, respectively. Data has been collected on the exracted load at 10 kV as well as electricity production from 35 MW wind power at 20 kV. This data was collected by Pite Energi for all hours of 2019 and used as input in the thesis work for simulations and calculations of the grid. The investigated 40 kV grid shows a reduced loss as load increases in the 10 kV grid as long as the increase follows the load variations for 2019. Compared to the losses for the base case, reduced losses are obtained in 40 kV networks with loads up to 16-18 MW. The report also shows that there are opportunities for further energy savings through regulating production, or energy storage in the wind farm. The difference in network losses between high and low load times is very small. This is largely due to the large difference between production and consumption in the grid. With the load variations measured for 2019, it shows that the limitations in the 40 kV network are primarily due to the thermal limits for both ordinary and reserve. The result also shows that today there is a good margin to the network's capacity limits and will most likely be able to handle any load increases that may come in the near future.

Renewable energy will presumably constitute most of the energy production within the next coming years. Both globally and in Sweden the governments continuously implement new guidelines to enable more renewable energy in the energy system. This implicates higher amount of intermittent energy resources, for instance wind power, which can be a challenge due to electricity demand and electricity production. There are several solutions which can be implemented in order to adapt the electricity production to the electricity demand, one of them is a power-to-power system.    This project aims to analyze whether a power-to-power system with hydrogen storage can be profitable. A power-to-power system is defined by storing the surplus power production from intermittent energy resources as form of hydrogen. The hydrogen will at a future time be generated back to power when the electricity demand increases. In the examined work the hydrogen is produced through a water electrolysis with electricity from wind power when the electricity prices are low. The hydrogen will be used in fuel cells to generate electricity which can be sold when the electricity prices are high. The project investigates two counties with different amount of installed capacities from wind power. Two scenarios are applied for the two counties, what distinguish each scenario is the limit of electricity price when the electricity from wind power starts being utilized to produced hydrogen instead of transferred to the electricity grid.   The results indicates that the electricity price need to reach a high level for the system to be profitable. It is not likely the electricity prices will reach that level more than a few times a year considering the electricity price levels the last couple of years.

För att minska de globala utsläppen och klara klimatmålen i Parisavtalet måste fossil elproduktion fasas ut och ersättas av förnybar energi. Förnybara energikällor, exempelvis vindkraft, har ökat kraftigt de senaste åren. Detta introducerar nya utmaningar då elproduktionen inte alltid stämmer överens med elbehovet eftersom förnybara energikällor inte kan kontrolleras på samma sätt som de fossila; vindkraftverken kan inte producera el utan vind. Detta får konsekvensen att elnätets stabilitet och elens kvalité blir sämre, samt att elpriset varierar kraftigare. Problemet kan lösas genom att köpa överskottsel och lagra energin när elbehovet är lågt, för att sedan sälja den när elbehovet är högt. På så sätt jämnas effektvariationerna ut. Att lagra energi i form av vätgas, har pekats ut som den mest lovande metoden för att genomföra detta i tillräckligt stor skala. Vätgas produceras i en elektrolysör av el och vatten när elbehovet, och därmed elpriset (spotpriset) är lågt. Vätgasen lagras sedan i naturliga och konstgjorda bergrum för de största anläggningarna, eller ovan jord i tankar och tuber för mindre anläggningar. När elbehovet och därmed elpriset i stället är högt omvandlas vätgasen till el i en bränslecell. I elektrolysören och bränslecellen produceras även spillvärme som kan utnyttjas exempelvis i ett fjärrvärmenät. Konstruktionen av vätgasanläggningar gör även en omvandling till vätgasdrift inom transportsektorn möjlig, vilket skulle medföra reducerade utsläpp av växthusgaser. Syftet är att visa vätgasens potential att bli en framtida energibärare och buffert i det svenska elnätet genom att studera olika design- och driftparametrar för en tänkt vätgasanläggning integrerad med värmekraftverket Heden, som drivs av Karlstads Energi AB. Den årliga fordonsvätgaskonsumtionen för Värmlandstrafik AB beräknas med hjälp av företagets totala körsträcka under 2020 ihop med kilometerförbrukningen vätgas för vätgasvarianterna av deras fordonstyper. Karlstads Energi AB:s årliga förbrukning beräknas genom att omvandla företagets mängd förbrukat bränsle under 2020 till den mängd vätgas som kan utföra samma arbete. De olika bränsletypernas energitäthet och de olika fordonens verkningsgrader används. För att simulera anläggningens årsintäkt konstrueras en modell i SIMULINK 9.2. Modellen har entimmes tidssteg vilket leder till 8760 tidssteg totalt. Spotpris tas in på timbasis och bestämmer om vätgas ska produceras i elektrolysören, konsumeras i bränslecellen för att producera el eller lagras tills senare. Spillvärmen från elektrolysören och bränslecellen säljs som fjärrvärme. Den beräknade årliga fordonsvätgaskonsumtionen delas upp till en daglig mängd med två fasta årliga nivåer. Värmlandstrafik AB använder en sommartidtabell vilket medför att förbrukningen sjunker under denna period. Anläggningens totala årsintäkt beräknas som såld el, fordonsvätgas och värme, minus köpt el och relaterade elhandelavgifter. Genom att bland annat variera storleken av anläggningens lagerstorlek samt elektrolysörens och bränslecellens märkeffekt byggs olika scenarion upp. Det reducerade utsläppet koldioxidekvivalenter beräknas genom att multiplicera vardera av de nuvarande bränslenas årsförbrukningar med respektive bränsles emissionsfaktor. Vätgasproduktionens utsläpp räknas som livscykelutsläppen för den konsumerade elen. 1360 ton vätgas/år är den årliga fordonsvätgaskonsumtionen som krävs för att tillgodose Värmlandstrafik AB:s och Karlstads Energi AB:s transporter. Den simulerade anläggningens årsintäkt är 51 – 65 MSEK/år beroende av anläggningens dimensioner och vilket spotpris som används. Bränslecellen beräknas ej vara lönsam i syftet att balansera elnätet. Ersättandet av de nuvarande bränslena med vätgas reducerar utsläppen med 4770 ton CO2eq/år räknat med svensk elmix, 1630 ton CO2eq/år räknat med nordisk elmix och 5870 ton CO2eq/år räknat med el köpt med ursprungsgaranti. Den framräknade fordonsvätgaskonsumtionen är stor nog för att installera en vätgasproduktion vid Heden. De miljömässiga fördelarna är också betydande. Med dagens verkningsgrader och avgifter krävs ett ostabilare spotpris för en bränslecell att bli lönsam. De ekonomiska simuleringarna är inte heltäckande nog för att möjliggöra några direkta beslut, men kan användas som grund. Fokus för fortsatta studier bör därför ligga i att inkludera investeringskostnader och avskrivningstider samt räkna på systemtjänsten som en bränslecell utför.