In the context of the fight against climate change, the electricity sector is experiencing a complete renewal. Power grids are undergoing a transformation from centralized and unidirectional systems to multilevel and more integrated networks with, among others, the insertion of intermittent Renewable Energy Sources (RES) on the production side and with the emergence of new consumer behaviors on the demand side. In this context, Battery Energy Storage Systems (BESS) are gaining momentum. Their excellent technical performances combined with a falling price make these storage solutions applicable to multiple scales and applications, ranging from the electrification of rural areas to the reinforcement of modern power grids. Large scale BESSs are complex systems, for which the electrochemical cells are only the elementary building blocks. Such storage systems consist of a hierarchical assembly of these cells, a complex control structure, a precise thermal management and a reversible power conversion apparatus, cooperating to ensure a smooth and safe operation. To deal with this complexity, BESS owners and operators need synthetic indicators to quickly assess the operation of their storage systems. In this work, this question of the monitoring of large scale BESSs is addressed with a selection, implementation and discussion of Key Performance Indicators (KPI). After a presentation of the multiple components constituting a BESS, a review of the main KPIs found in the literature is proposed. This preliminary phase concluded with the definition of four main categories covering the multiple aspects of the operation of a BESS: operation, performance, ageing and safety. Where needed, a choice was made to choose the estimation techniques offering the best tradeoff between accuracy, ease of implementation and computational load. Then, the overall implementation strategy used to take advantage of the large amount of data available was presented. The results were obtained for actual large-scale Li-Ion BESS projects, covering multiple applications and chemistries. Based on these illustrative results, the robustness and the accuracy of the indicators was discussed. More importantly, a special attention was paid to the methodology, meaning and interdependencies of these KPIs to enable battery owners to better understand their system. / Inom ramen för kampen mot klimatförändringar upplever elsektorn en fullständig förnyelse. Kraftnät genomgår en omvandling från centraliserade och enkelriktade system till flernivå och mer integrerade nätverk, bland annat införande av intermittenta förnybara energikällor på produktionssidan och med uppkomsten av nya konsumentbeteenden på efterfrågesidan. I detta sammanhang får batterilagringssystem fart. Deras utmärkta tekniska prestanda i kombination med ett fallande pris gör att dessa lagringslösningar är tillämpliga på flera skalor och applikationer, allt från elektrifiering av landsbygden till förstärkning av moderna elnät. Storskaliga batterilagringssystem är komplexa system för vilka de elektrokemiska cellerna endast är de grundläggande byggstenarna. Sådana lagringssystem består av en hierarkisk sammansättning av dessa celler, en komplex kontrollstruktur, en exakt termisk hantering och en reversibel kraftomvandlingsapparat, som samarbetar för att säkerställa en smidig och säker drift. För att hantera denna komplexitet behöver batterilagringssystem-ägare och operatörer syntetiska indikatorer för att snabbt utvärdera driften av deras lagringssystem. I detta arbete behandlas denna fråga om övervakning av storskaliga batterilagringssystem med ett urval, implementering och diskussion av viktiga resultatindikatorer. Efter en presentation av de flera komponenterna som utgör ett batterilagringssystem föreslås en översyn av de viktigaste resultatindikatorer som finns i litteraturen. Denna preliminära fas avslutades med definitionen av fyra huvudkategorier som täcker flera aspekter av driften av en BESS: drift, prestanda, åldrande och säkerhet. Vid behov gjordes ett val för att välja uppskattningstekniker som erbjuder bästa -ivavvägning mellan noggrannhet, enkel implementering och beräkningslast. Sedan presenterades den övergripande implementeringsstrategin som användes för att dra fördel av den stora mängden tillgängliga data. Resultaten erhölls för faktiska storskaliga Li-Ion BESS-projekt, som täcker flera applikationer och kemister. Baserat på dessa illustrativa resultat diskuterades indikatorernas robusthet och noggrannhet. Ännu viktigare var att särskild uppmärksamhet ägnades åt dessa resultatindikatorer metodik, betydelse och beroende av varandra för att möjliggöra för varje batteriägare att bättre förstå sitt system.

The monitoring and supervision of large scale solar photovoltaic plants becomes more and more important nowadays, with the increase of the installed power. The detection system and the reactivity must be improved in order to allow the plants to run at their best capacity. One way to improve that detection is the setup of alerts triggering for certain types of defaults concerning the performance of the inverters or the plant itself. That setup can be optimized by analytical analysis on the historic data of the plant, and adjusted for each plant, depending on its behavior. Another way is to calculate robust indicators such as the performance ratio, which corresponds to the efficiency of the plant, regardless the type of installed panels. This indicator depends on the electricity production and the received irradiance. In order to have an accurate measure of that indicator, a work on the reconstitution of the missing data must be done for the irradiance measure. That reconstitution enables to have access to a robust measure of the performance ratio and thus to improve the monitoring of the performances of the plant. / Övervakningen av fotovoltaisk anläggning blir mer och mer viktigt idag, med ökningen av den installerade kraften. Detekteringssystemet och reaktiviteten måste förbättras för att växterna ska kunna köras med bästa kapacitet. Ett sätt att förbättra detekteringen är att upprätta larm som utlöser för vissa typer av standardvärden beträffande inverterarnas prestanda eller själva anläggningen. Denna inställning kan optimeras genom analytisk analys av anläggningens historiska data och justeras för varje anläggning, beroende på dess beteende. Ett annat sätt är att beräkna robusta indikatorer som prestandaförhållandet, vilket motsvarar anläggningens effektivitet, oavsett typ av installerade paneler. Denna indikator beror på elproduktionen och den mottagna bestrålningen. För att ha ett exakt mått på den indikatorn måste ett arbete med rekonstitution av de saknade uppgifterna göras för bestrålningsåtgärden. Denna rekonstitution möjliggör åtkomst till ett robust mått på prestandaförhållandet och därmed förbättrar övervakningen av anläggningens prestanda.

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.

The aim of this report was to examine the viability and identify possible benefits of implementing a PV and hydrogen storage system in Skolfastigheter AB’s facilities in Uppsala. The idea is that surplus solar energy from the school’s PV system is directed towards hydrogen gas production. By storing the produced hydrogen gas, it can supply the school with electricity in times of low solar radiation, such as during the winter.  The study was conducted using data from Tiundaskolan in Uppsala. Three models were designed, investigating the number of self-sufficient days from utilizing the hydrogen gas, considering factors such as installed PV capacity and total yearly electrical energy consumption. All models were based on data from Tiundaskolan. Model A showcases the implementation of a PV and hydrogen storage system at Tiundaskolan specifically, while Model B takes varying electrical energy consumptions into consideration. Model C dimensions a school’s energy system to enhance the number of self-sufficient days, and thereby increases the favorability of the implementation of hydrogen storage. The results show that considering current conditions, Tiundaskolan would only be self-sufficient on hydrogen for almost 3 days, and the number of days increases significantly when more PV capacity is installed. Additionally, the dimensioning proposed in Model C further enhances the impact of installing more PV capacity.  The conclusion was drawn that implementation of this type of system can be viable for Skolfastighter AB, if the safety aspects of hydrogen gas are taken into consideration. The conditions for successfully utilizing hydrogen storage include the size of the PV system, the total yearly energy consumption, and features such as the rooftop design and the school’s location. Identified benefits of using hydrogen storage include the ability to balance the electrical grid and reduce capacity deficiency, contributing to the technological development of hydrogen gas and being at the forefront of the green transition. Furthermore, the ability to stay self-sufficient through hydrogen storage could be crucial for a school in the event of a crisis or power shortage since it can contribute with security to the local society.

In countries with cold winters and substantial snowfall, such as Sweden, snow losses can limit the energy generated from PV systems by up to 100% monthly and up to 20% annually. Therefore, snow loss modeling is required to effectively predict the generated PV electricity in these locations. This thesis investigates the implementation of snow loss models to improve theaccuracy of hourly simulated Photovoltaic (PV) power generation. Four different snow loss models were identified as potential options, which was selected based on the purpose and constraints of the PV power simulation model used. The evaluated models include the Marion Model, The Modified Marion Model, The SunPower Model, and the Combined model, which is a combination of the three other models. The assessment of the snow loss models was conducted using 29 PV reference systems, predominantly located in Sweden (26 systems), with two additional systems in Norway and one in Estonia. The reference systems include known system characteristics, such as PV module parameters, tilt, azimuth, and measured PV power generation data, depending on the systems, between the years 2017-2023. Initially, all PV reference systems were simulated without applying the snow loss model, followed by simulations incorporating the snow loss models. The performance of the snow loss models were evaluated by the difference in the coefficient of determination, R2, before and after the respective snow loss model was implemented. Furthermore, all tested models were optimised based on various parameters. For all models except the SunPower model, the optimisation involved adjusting the snow clearing coefficient, and the snow depth threshold, THsnowfall. Following the model optimisation and comparison, all snow loss models demonstrated improved accuracy in compared to the baseline simulations. Among these models, the Modified Marion model was recommended due to its low complexity and its notably improved accuracy. Specifically, the Modified Marion model yielded an average monthly improvement in R2 values ranging from 0.1 to 0.14 for all winter months except for March (0.004), with an overall average improvement of 0.0094. The estimated annual snow losses using the Modified Marion model ranged from 0.02% to 12% over the period from 2017 to 2023, with most systems experiencing values between 2% and 6%. Finally, the monthly losses were estimated to reach up to 100% for the northernmost systems. The main challenges of the recommended snow loss model include lower performance in March compared to other winter months for most systems, as well as an overall decreased accuracy for the northernmost systems, where substantial snowfall is present. However, for systems with moderate snowfall, the model generally demonstrated increased performance, which can be of value for Distribution System Owners conducting PV power simulations for grid planning and for solar power forecasting.

This thesis examines if the software AFRY Intelligent Scenario Modelling can be used to model for the purpose of a level 3 Probabilistic Safety Analysis (PSA). A Gaussian puff model is developed in AFRY Intelligent Scenario Modelling, capable of predicting the resulting ground deposition [Bq/m2] of the radionuclides I-131 and Cs-137 following a fictional accident at a Nuclear Power Plant (NPP). Inputs to the model are precipitation and wind conditions as well as a source term representing a release of radionuclides. In order to test the validity of the model, it is first run using weather data and source term from the Fukushima Daiichi NPP accident in 2011, and the resulting ground deposition is compared to empirical data. The comparison indicates that the model yields reasonable results. Then the model is applied to the Forsmark NPP, in order to simulate what the ground deposition of I-131 and Cs-137 would be two days after a fictive accident. Using probability density functions (PDF) for rain and wind conditions, as well as the source term from the Fukushima Daiici accident, the model is run probabilistically for different weather parameters. Furthermore, the model is extended to be able to calculate whole body effective dose [mSv] to a person of the general public at any given distance, up to 100 km, from the source term. These dose calculations were done around Forsmark NPP using the same conditions as above and even though the whole body effective dose to a person of the general public was low this could be explained through short time of exposure. Given this the exposure model was assumed to give reasonable results. The model has been shown being able to disperse radionuclides in the air and predict the resulting ground deposition after the validation. This in combination with being able to probabilistically calculate ground deposition and whole body effective dose to a person of the general public shows that AFRY Intelligent Scenario Modelling is suited for modelling to be used in a level 3 PSA.

Efforts worldwide are focused on combating climate change by reducing greenhouse gas emissions through a transition to sustainable energy, driven by specific goals to be achieved by 2030. One challenge in weather-dependent electricity production is balancing demand with supply, which is where Pumped Hydro Energy Storage (PHES) plays a crucial role. PHES systems are based on traditional hydroelectric technology and involve pumping water back to upper reservoirs using large pumps. In Sweden, there are three PHES facilities in the SE3 pricing area, Letten, Kymmen, and Eggsjön. The design of a PHES system requires careful selection of appropriate turbines. The Francis turbine is a common type of turbine and is widely used in hydropower globally. Availability of unused mine system creates the potential for expanding PHES in Sweden to enhance renewable energy integration. A profitability study examined various scenarios by varying pump parameters revealing profitable options. According to this study, Francis turbines and a separate pump system with specific flow rates 2 to 7 cubic meters per second, turned out to be most profitable for this specific project in Norberg. One of the top scenarios identified in the study showed profitability over expected lifespans, although the most optimistic projections are based on several assumptions. The research highlights the importance of PHES in addressing the challenges of renewable energy integration and balancing electricity supply and demand. The findings suggest significant potential for PHES expansion in Sweden, although the impact on electricity production will likely evolve gradually. The study finally concludes the specific design and optimization of the PHES system in Norberg, for maximizing renewable electricity production and economic viability.

Som ett led i en naturlig utveckling har de nordiska länderna tillsammans beslutat sig för att minska barriärerna och harmonisera processer mellan länderna och på så sätt möjliggöra för en gemensam nordisk elmarknad. År 2008 påbörjades arbete med harmoniseringen, vilken syftar till att möjliggöra för kunden att handla sin el från samtliga nordiska länder. Tillförlitliga elleveranser och effektiva och konkurrensmässiga elpriser ska förändra konkurrensbilden och elmarknaden ska anta ett mer marknadsanpassat utseende.    Syftet med den här rapporten är att studera hur ett elföretag kommer att påverkas av utvecklingen mot en gemensam nordisk slutkundsmarknad. I ett första steg presenteras nuläget på den svenska elmarknaden, vartefter ett scenario har tagits fram, baserat på förväntade förändringar på elmarknaden. Scenariot syftar till att ge en överskådlig bild av elmarknaden år 2020, men har sin tyngdpunkt i arbetet med en gemensam nordisk slutkundsmarknad. Rapporten avslutas med allmänna rekommendationer om hur ett nät- och elhandelsföretag bör agera för att fortsätta att vara framgångsrika på elmarknaden.  En framtida gemensam nordisk slutkundsmarknad kommer att bestå av 15 miljoner elanvändare och en helt ny konkurrenssituation kommer att växa fram. Nya aktörer, uppköp och klusterbildning kommer att prägla den marknad som ett elföretag ska verka på, på en framtida gemensam nordisk slutkundsmarknad.  Intervjuer, workshops och enkäter visar att harmonisering kommer att leda till ökade kostnaderna för elföretagen. Detta då de exempelvis måste implementera nya IT-system som är kompatibla med övriga system i Norden, samt att företagen måste kunna hantera så väl språkskillnader som kulturella skillnader. Mindre elföretag kommer att få det svårt ekonomisk i ett initialt skede och bör därför fundera över olika strategiska vägval på den nordiska slutkundsmarknaden. Dessa företag rekommenderas generellt att satsa på stark regional anknytning, medan de mellan - och större företagen bör fundera på internationell närvaro. / In 2008, the harmonisation of the Nordic electricity markets was initiated as a measure to reduce the barriers between the countries and to harmonise the utilities’ internal processes. Thereby, the overall goal of creating a common Nordic electricity market will be fulfilled. In this market, customers will be able to purchase electricity from a retailer based in any of the participating markets, creating a reliable supply and a highly competitive and efficient market character.   By analysing the as-is situation of the Swedish electricity market and creating a scenario of the common Nordic electricity market in 2020, the report aims at assessing the impact on a utility from the change of market situation. The scenario focuses on changes derived from the harmonisation but also includes macro trends. In the report, general recommendations are presented on how DSOs and retailers can manage the transformation prosperously and profitably.   The future Nordic electricity market will consist of 15 million end users and a competitive landscape, new to every utility in the energy sector, will emerge. The new market will be characterised by new players, frequent mergers and acquisitions and cluster strategies.   By conducting interviews and workshops, and by carrying out surveys, it could be concluded that the harmonisation inevitably will result in increased costs for the utilities. Investments in new IT-systems compatible with systems in the other Nordic countries will be prerequisites for participating in the new market, as well as language training for customer service. In addition the utilities will face challenges in operating in countries with different cultures. Especially small sized utilities will be hit economically in the short term, being forced to take on the significant investments. The way forward for a small utility is thus strategic reviews, preferably with the result of focusing on regional presence. Medium and large sized utilities should on the contrary investigate and focus on the direction of internationalisation.

Region Värmland har satt upp miljömålet att minska sina koldioxidutsläpp och sin energiförbrukning, samtidigt önskas att spara in så mycket pengar som möjligt. Eftersom värme- och kylsystemet på Centralsjukhuset i Karlstad (CSK) står för en stor del av hela regionens energiförbrukning kan det ge god effekt att driftoptimera systemet. Systemet består av fyra bergvärmepumpar, två kylvärmepumpar, frikyla från marklagren, fjärrvärme samt tre kylmaskiner.   Studien syftar till att undersöka hur region Värmland kan komma närmre sina miljömål, minska sina driftskostnader, samt att förstå vilka begränsningar som deras värme- och kylsystem har. Målet var att ta fram driftstrategier utifrån systemets begränsningar för perioden april-september, samt att redovisa hur mycket köpt energi, koldioxidutsläpp samt pengar som kan sparas om systemet körs enligt dessa strategier.   En modell av systemet har byggts i simuleringsprogrammet Simulink och kalibrerats mot mätdata från den studerade perioden. Eftersom ett av målen i studien varit att ta reda på mer om begränsningarna i marklagren har stor vikt lagts på att modellera borrhålen och frikylevärmeväxlaren.   Studiens resultat visar att den begränsande faktorn för frikylan är marklagren och brinevätskans temperatur, det finns därmed inte mycket mer effekt att hämta genom att öka flödet genom värmeväxlaren. Att köra bergvärmepumparna och frikyla samtidigt ger därför bra förutsättningar att få ut mer frikyla och minska frysrisken i borrhålen. Ett alternativ till att köra bergvärme och frikyla samtidigt är att investera i nya kylvärmepumpar som har ett högre COP än de nuvarande, om det är lönsamt beror dock på hur stor investeringskostnaden är.   Båda dessa alternativ har potential att minska driftens koldioxidutsläpp med ca 35 ton och mängden köpt energi med ca 1 GWh, vilket motsvara ca 1,1 % respektive 1,6 % av hela Region Värmlands utsläpp och köpta energi för hela 2021. Dessa två alternativ kommer även minska driftskostnaderna mest (ca 0,3–0,4 Mkr sparat) så länge elpriset inte stiger till ca 2 kr/kWh, då blir det billigast att bara använda fjärrvärme som värmekälla.   Den driftstrategi som rekommenderas är att under hela perioden låta bergvärmepumparna gå maximalt och därmed även få ut maximalt med frikyla, då denna strategi har stor potential att spara driftskostnader och hjälpa Region Värmland att nå sina miljömål utan att behöva investera i nya komponenter. Hur koldioxidutsläpp och energi värderas i miljömålen bör dock utredas inför nya målsättningar, då det kan ge fördel åt att i stället köra fjärrvärme under sommarmånaderna.