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Ett vitalt steg mot en framtid med 100% förnybar energi är förmågan att storskaligt kunna lagra energi för dagarna då solens strålar inte kommer fram eller då det inte blåser. Detta arbete syftar till att redovisa bakgrund, teknik samt framtid för pumpkraft som energilagringsteknik. Arbetet grundas på litteraturstudier och intervjuer, som resulterar i en fallstudie som överblickar två olika typer av pumpkraftverk, på två olika platser i Sverige. Dessa två pumpkraftverkens utformning skiljer sig markant på grund av olika geografiska faktorer. Pumpkraftverken, tillsammans med elpriser hämtade från elbörsen Nord Pool, analyseras i fallstudien utifrån tre tidshorisonter: dygn, vecka samt månad. Kraftverkets drift över dessa tre tidshorisonter studeras utifrån ett lönsamhetsperspektiv, där drift endast förekommer om fördefinierade krav för lönsam verksamhet uppfylls. Fallstudiens syfte är därmed att överblicka ett pumpkraftsystem, och resulterar därmed i en förenkling av verkligheten. Ett verkligt pumpkraftsystem har möjlighet att drivas betydligt mer dynamiskt, som vid likadana prisförhållanden är mer fördelaktigt. Slutsatsen som dras från fallstudiens resultat är att pumpkraftverket skulle behöva medföra en särskild nytta utöver att utnyttja elprisvariationer, som trots de diskutabla ekonomiska samt ekologiska förutsättningarna i Sverige gör ett pumpkraftsprojekt intressant. Men internationellt sett så kan det finnas större anledning att investera i pumpkraft, på grund av olika energimässiga samt ekonomiska förhållanden. / A vital step towards a future with 100% renewable energy is the ability to store energy at a large scale for the days when the sun’s rays will not pass through the clouds or for when there is no wind. This paper aims to present the background, engineering and future for pumped hydro energy storage. The paper is based on literature and interviews, which result in a case study, which spans two different pumped storage power plants, on two different locations in Sweden. The modelling of these two power plants is significantly different, due to different geographical factors. These pumped storage plants, along with electricity prices from the power market Nord Pool, are analysed in the case study from three time perspectives: day, week and month. The operation for the two pumped storage plants over these three time perspectives are studied from a profitability perspective as well, whereas operation does not occur unless the criteria for profitability are met. The goal of the case study is to foresee a pumped hydro energy storage system, and therefore its results are a simplification of reality. A real pumped hydro energy storage system has the tools to be operated more dynamically, which under similar price conditions is more favourable. In conclusion drawn from the results of the case study, the pumped storage plant would have to bring a certain benefit beyond utilizing electricity price variations, which despite the arguable economic and ecological reasons in Sweden would make said pumped hydro energy storage project interesting. However internationally, there are more reasons for investing in pumped hydro energy storage, due to different energy systems as well as economic reasons.

The Government of Guyana sees the Information and Communication Technology (ICT) diffusion as critical in quality of life improvement. Together with the United Nations Development Program (UNDP) they are conducting a project to provide internet access to Hinterland, Rural and Poor Communities (HRPC) through Very Small Aperture Terminals (VSATs) powered by stand-alone hybrid energy systems including solar Photovoltaics (PV) and Li-Ion batteries. The project is facilitated by the UNDP Office of Information Management and Technology (OIMT), using the 7-step process (UNDP best practice for green energy related implementations). This report aims at improving the 7-step process by critically reviewing the UNDP Guyana HRPC project, drawing also on experience from previous projects. The results highlight deviations from the original process and the recommended actions are to create principles and guidelines to follow when such deviations happen. It is further recommended to expand the process, make it more flexible and applicable to different types of projects. Finally, knowledge sharing between United Nations (UN) organs and UNDP units could be highly beneficial when creating a more flexible process. Since the ICT diffusion is seen as critical in quality of life improvements, this report also aims to create a framework to evaluate what impact the project can have on the people. Intended outcomes of the project, issues and key priorities identified by the communities, lessons learnt from other projects and relevant concepts are the basis for the suggested Key Performance Indicators to monitor. By using formal data collection, with the expressed permission of the user, ICT activities can be measured and evaluated. Indicators on health, education, economic activities, business development etc. can be easily gathered this way. Complemented by surveys and/or interviews in line with the UNDP Sustainable Livelihood Framework for qualitative aspects and technical monitoring of the Solar PV system, this could enable sufficient information to assess the quality of life improvements and view the success of the implemented project. / Guyanas regering ser spridningen av Informations- och kommunikationsteknik som en viktig del i arbetet mot en förbättrad levnadsstandard. Tillsammans med Förenta Nationernas utvecklingsprogram (UNDP) har regeringen startat upp ett projekt som ska förse Guyanas inland, landsbygdsområden och fattiga samhällen med internetanslutning. Detta görs genom Very Small Aperture Terminals (VSATs), kombinerad mottagare och sändare för datatrafik (vanligen en parabolantenn), vars eltillförsel kommer från fristående hybridenergisystem bestående av solceller samt Li-Ion batterier. Projektet verkställs av UNDPs byrå för information, management och teknologi (OIMT) som använder UNDPs bästa praxis för utförandet av energirelaterade projekt, 7-stegs processen. Syftet med denna rapport är att förbättra 7-stegs processen genom att kritiskt granska UNDP och Guyanas regerings gemensamma projekt. Resultaten påvisar åtskilliga avvikelser från den ursprungliga 7-stegs processen och de rekommenderade åtgärderna är att skapa grundprinciper samt riktlinjer att följa då ett projekt avviker på detta sätt. Det är vidare rekommenderat att expandera processen, göra den mer flexibel, för att smidigt kunna använda den för olika typer av projekt. Kunskapsdelning mellan FN organ samt enheter inom UNDP skulle vara högst fördelaktigt vid skapandet av en mer flexibel process. Då informations- och kommunikationsteknik ses som en viktig del i arbetet mot en förbättrad levnadsstandard är syftet med rapporten vidare att utvärdera vilken påverkan projektet har på invånarna i de berörda områdena. Föreslagna indikatorer för uppföljning av detta är grundade i de avsedda resultaten för projektet, samhällenas egna prioriteringsområden, lärdomar dragna från tidigare utförda projekt samt relevanta koncept. Genom datainsamling av internetbaserade aktiviteter, med explicit godkännande av användaren, kan indikatorer för hälsa, utbildning, ekonomiska aktiviteter, företagande osv. mätas och utvärderas. Kompletterat med intervjuer i linje med UNDPs ramar för hållbara levnadsvillkor (för att mäta de kvalitativa aspekterna av internetanslutningen) och med tekniska övervakningssystem av solcellernas prestanda bör det vara tillräckligt med information för att bedöma förbättringarna i levnadsstandard och projektets framgång

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.

A great deal of interest lies in detonative combustion due to its destructive potential and the theoretical thermodynamic advantages over traditional deflagration devices used for propulsion and energy. High energy materials and explosives combustion products and temperature must be characterized to gain greater insight into the energy release mechanisms, allowing for more tailored deployment. Predictive models for detonations employ various types of state equations, and temperature can be used as a check on the equation validity. However, the extreme environment of explosives is incredibly challenging to evaluate temperature. Additionally, these reactions are extremely fast, taking place over microseconds, and have an extremely large dynamic range, with pressures and temperatures exceeding 30 bar and 3000 K, respectively. For harnessing detonations for energy and propulsion, rotating detonation engines (RDEs) have received much attention due to their simple design and ability to be fed continuously. Many of the same challenges faced in characterizing explosive detonation are encountered in the flowfield of RDEs. These devices require fast measurements (MHz) in extreme environments, which allow the development of better models. The work discussed in this dissertation presents the development and demonstration of laser absorption spectroscopy (LAS) sensors for the characterization of detonative flows in an RDE and high-explosive material's fireballs. The development cycle is discussed, including selecting the target gases, line selection, system design, validation, and demonstration. Temperature and H2O measurements within the detonation channel of a CH4/Air fired RDE are presented, which show incomplete detonation combustion and a secondary combustion mode from unreacted products.

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.