Most of the world’s electricity is being generated through conventional sources of energy like coal and nuclear. People are realizing the dire effect of using these fuels, and the amount of CO2 being released into the environment. Therefore, in recent year there has been a shift in emphasis towards cleaner ways of generating electricity. One such recent trend is solar photovoltaics (PV), which has seen rapid growth over the years. This ever-increasing trend of adopting PV system allows consumers to be producers or “Prosumers”. Due to the irregular production capability of solar PV, the need for an energy storage system like a battery bank is on the rise as well. This report evaluates how solar PV can be used in combination with a battery bank to supply the annual electricity demand for a household with little to no support from the grid. The building is assumed to be located in Bangalore, India. The energy demand for the household is estimated based on the requirements of a basic Indian house standard. The size and configuration of each component have been done with regards to the total load demand. Furthermore, the cost of the whole system is estimated in order to evaluate the feasibility of the grid-tied system from an economic perspective. The results show that a PV system consisting of four 270W solar panels, a battery bank of eight150Ah lead-acid batteries and a 48V 4kW inverter is required to meet the annual energy demand of the house. The results show that from a technical standpoint, the above-mentioned technology is feasible. The results from the economic evaluation show that the localized cost of energy(LCOE) for the system is ₹6.01/kWh or € 0.078/kWh or 0.84SEK/kWh and the payback time for the given system is 16.19 years. On the bright side, there are new technological advancements in the PV field every day, which could mean that an energy system of this type can be an achievable and practical alternative. Most of the world’s electricity is being generated through conventional sources of energy like coal and nuclear. People are realizing the dire effect of using these fuels, and the amount of CO2 being released into the environment. Therefore, in recent year there has been a shift in emphasis towards cleaner ways of generating electricity. One such recent trend is solar photovoltaics (PV), which has seen rapid growth over the years. This ever-increasing trend of adopting PV system allows consumers to be producers or “Prosumers”. Due to the irregular production capability of solar PV, the need for an energy storage system like a battery bank is on the rise as well. This report evaluates how solar PV can be used in combination with a battery bank to supply the annual electricity demand for a household with little to no support from the grid. The building is assumed to be located in Bangalore, India. The energy demand for the household is estimated based on the requirements of a basic Indian house standard. The size and configuration of each component have been done with regards to the total load demand. Furthermore, the cost of the whole system is estimated in order to evaluate the feasibility of the grid-tied system from an economic perspective. The results show that a PV system consisting of four 270W solar panels, a battery bank of eight 150Ah lead-acid batteries and a 48V 4kW inverter is required to meet the annual energy demand of the house. The results show that from a technical standpoint, the above-mentioned technology is feasible. The results from the economic evaluation show that the localized cost of energy (LCOE) for the system is ₹6.01/kWh or € 0.078/kWh or 0.84SEK/kWh and the payback time for the given system is 16.19 years. On the bright side, there are new technological advancements in the PV field every day, which could mean that an energy system of this type can be an achievable and practical alternative.

Kite energy systems are an emerging renewable energy technology. Unlike conventional turbines, kite energy systems extract wind power using tethered kites which can move freely in the wind or underwater in an ocean current. Due to the mobility, kite power systems can harvest power from regions with higher and steadier power density by moving in high-speed cross flow motion. An airborne kite energy system harnesses wind power at an altitude higher than the conventional wind turbines, while an undersea kite energy system extracts power close to the ocean surface. In this dissertation, the physical limitation, mathematical modeling, and control system design of the kite energy systems are studied. First, three major physical effects that are acting on the kite energy systems are investigated, including potential force, steady aero-/hydro-dynamic force and added mass effects. Furthermore, the dissipativity of the steady aero-/hydro-dynamic forces with respect to the apparent velocity is established. Based on this analysis, the power generation limit of the kite energy systems is studied. A power limit formulation is given which generalize the two-dimensional result to three-dimensional case. The different physical phenomenon is modeled in different coordinate systems, the difference of the density, viscosity between air and water are significant, and the kite energy system can operate in two distinct modes. To combine different physical effects into a single simulation framework, the equivalences of the kite model in different coordinate systems are established through kinematic analysis. Using these equivalent relations, a unified simulation model for airborne and undersea kite energy systems are derived. The control system design of kite energy systems is also investigated. The resulting equations of motion of kite energy systems are highly nonlinear. Therefore, Lyapunov methods are used to analyze the system behavior. Three different techniques are reviewed, including Lyapunov analysis for autonomous and non-autonomous systems, the ultimate boundedness and input-to-state stability and passivity methods. For the fixed tether length kite energy systems, the ultimate boundedness of the kite translation is established through the dissipativity of the steady aero-/hydro-dynamic force. For the variable tether length kite energy system, the input-to-state analysis is used to design the tether tension that guaranteed the boundedness of the kite translation. In both cases, the Lyapunov based methods are used to design kite rotational control systems which result in PD type control signals. Although this control scheme generates consecutive power cycles for kite energy systems. It is shown that the kite aero-/hydro-dynamical performance is unstable in the simulation which could result in unsteady power generation. To provide a steadier performance in kite translation and power output, the relative dynamics of the kite translation is first proposed. In this model, the kite apparent speed and attitudes, the angle of attack and side-slip angle, are used to describe the kite translation. A nonlinear control scheme is designed to regulate the angle of attack and side-slip angle using back-stepping methods by using the kite angular velocity and control inputs. However, due to the magnitude limit of the angular velocity, the residual error of the apparent attitude tracking remain large for the large desired angle of attack and side-slip angle. To achieve a better power harvesting and aero-/hydro-dynamics performance, the geometric properties of kite angle of attack and side-slip angle are studied. A geometric attitudes trajectory is constructed to track given apparent attitudes. A rotational control system is designed based on the back-stepping and sliding mode methods for the desired geometric attitude, and the high gain observer is applied to acquire the information needed for the rotational control signal. Through the geometric apparent attitudes tracking control algorithm, the angle of attack and side-slip angle act as direct control inputs to the kite translational motion. The kite translational dynamics under the geometric apparent attitude tracking is studied. These dynamics give the possibility of controlling the kite translational motion only through the rotational control scheme.

En fortsatt ökning av koldioxidutsläppen leder ekosystemen på jorden mot snabba, farliga och irreversibla klimatförändringar. Den svenska skogsindustrin är en viktig aktör för att tillfredsställa framtidens efterfrågan på förnyelsebara bioprodukter. Produktionsökningen innebär ökad påtryckning på de svenska skogsmarkerna. Samhället, regeringen, företag och individer har ett ansvar att avverkningen av skog förblir hållbar. Reningsverken inom massa- och pappersindustrin producerar en stor andel biomassa i form av bio- och fiberslam. Bio- och fiberslamm innehåller näringsämnen som kan returneras till skogen. Uppgraderingen av biomassa till biokol har påvisade egenskaper som förbättrar skogsmarkens bördighet, främst genom att höja markens pH-värde. Biokol förbättrar hållningen av näringsämnen i marken genom katjonsadsorption, vilket påverkar träd och växters tillväxt. Markens sammansättning förändras när biokol tillförs, vilket påverkar den biologiska mångfalden i ekosystemen. Biobränsleaskan som utvinns från eldningspannorna inom pappersindustrin innehåller baskatjoner med alkaliskt pH-värde, vilket motverkar försurning i skogsmarker. Nackdelen med biomassa är den höga bulkdensiteten, vilket påverkar logistiken kring transport och lagring. Det finns metoder för att lösa problemen med logistiken, exempelvis genom sammanpressning. Sammanpressning är en väl beprövad metod för att uppgradera biomassan till pellets och förbättra biomassans egenskaper. Omvandlingen av biomassa till pellets ökar densiteten, mekaniska hållfastheten och gör att fuktupptagningsförmågan minskar. Pelletering medför att en homogen produkt kan produceras och levereras. Syftet med denna studie var att öka kunskaper om hur lignin som additiv, samt hur mekanisk kraft påverkar näringspelletsens egenskaper samt energianvändning.  För att producera pellets genomgicks två moment, en förundersökning och en försöksmatris. Målet med förundersökningens var att införskaffa riktvärden och ge ett underlag till försöksmatrisen. Försöksmatrisen är en fortsatt studie på hur ligninhalt och mekanisk kraft påverkar näringspellets egenskaper. Ligninhalten som analyserades var 5, 10, 15 och 20 % med mekanisk kraft på 5, 10 och 15 kN. Näringspelletsen har utvärderats utifrån egenskaperna densitet, hårdhet, pH, fuktupptagningsförmåga samt energianvändning. För att pelletera de olika blandningarna användes singel-pelletspressen som finns på Karlstad Universitet. Pelletsegenskaperna testades i labblokalerna på Karlstad Universitet.  Resultatet visar att testserien med mekanisk kraft på 15 kN och ligninhalten 20 % resulterade i högst densiteten, hårdhet, fuktupptagningsförmåga samt näst högst energianvändning. Studiens testserier varierade enligt följande: Densiteten i studien varierar mellan 843,5- 1 054 kg/m3 Hårdheten i studien varierade mellan <1–3,7 kg Fukthalten i pelleten varierade mellan 8,7 % och 9,2 % efter 96 timmar pH-värdet varierade mellan 8,7–9,58 efter 24 timmar och minskade mellan 2- 4,9 % efter 48 timmar Energianvändningen varierade mellan 105,5- 129,5 J / Continued increase in carbon dioxide emissions lead the ecosystems towards rapid, dangerous and irreversible climate change. The Swedish forest industry is an important operator to satisfy the future demand of renewable bio products to reduce the use of fossil fuels. The increase in production means increased pressure on the Swedish forests. Society, government, companies and individuals have a responsibility to secure that the harvesting of forests remains sustainable. The wastewater treatment plants in the pulp and paper industry produce a large proportion of biomass, in form of bio and fiber sludge. Bio and fiber sludge contains nutrients that can be returned to the forest. The upgrade of biomass to pyro-char has proven properties that improve the fertility of the forest, primarily by increasing the soil's pH value. Pyro-char improves the retention of nutrients in the soil by cation adsorption, which affects the trees and plant growth. The composition of the soil changes as pyro-char is added, and the change in composition affects the biodiversity in ecosystems. The biofuel ash extracted from the heating boilers in the paper industry contains basic cations and alkaline pH, which counteracts acidification in forest land. The disadvantage of biomass is the high bulk density, which affects the logistics of transport and storage. There are methods for solving the problems in logistics, for example compression. Compression is a well-proven method for upgrading the biomass to pellets and improving the physical properties of the biomass. The conversion of biomass into pellets increases the density, mechanical strength and the moisture absorption capacity decreases. Pelletizing biomass results in a homogeneous product can be created and delivered as pellets. The purpose of this study is to increase the knowledge on how lignin as an additive, and how mechanical force affects the physical properties of the nutritional pellets. The production of nutrition pellets consists of two stages, a preliminary investigation and a test matrix. The purpose of the preliminary study is to acquire guideline values ​​and provide a basis for the experimental matrix. The experimental matrix is ​​a continued study of how lignin content and pressure affect the physical properties of the nutrition pellet. The lignin content that was analyzed was 5-20 % with mechanical force that varied between 5, 10 and 15 kN. The nutritional pellets are evaluated based on the properties density, hardness, pH, moisture absorption capacity and energy use. The single-pelletizer press, located at Karlstad University, was used to pelletize the different mixtures. The pellet properties were evaluated at the laboratory at Karlstad University. The result shows that the test series with a pressure of 15 kN and the lignin content of 20% resulted in the highest density, hardness, moisture absorption capacity and the second highest energy consumption. Depending on the mechanical force and lignin content used, the parameters varied as follows. The density varies between 843.5 – 1,054 kg/m3 The hardness ranged between <1 and 3.7 kg The moisture content of the pellets varied between 8.7% and 9.2% after 96 hours The pH-value varied between 8.7-9.58 after 24 hours and decreased between 2- 4.9 % after 48 hours The energy consumption varies between 105.5-129.5 J

Increased use of renewable energies that is taking place all over the world is having a very important impact on the photovoltaic solar energy industry. This means of obtaining electrical energy is one of the most promising ones nowadays, thanks to the fact that it is a technology of easy installation and maintenance. However, the number of hours that a photovoltaic system works at maximum power depends almost entirely on environmental conditions, mainly in terms of solar irradiance.Solar irradiance is a magnitude that measures the power released by sunlight per unit area; the higher it is, the more power the photovoltaic system will generate.Therefore, it is very important to measure this magnitude in order to obtain data that either can give information about which is the best place to install a photovoltaic system or expect the device performance.Unfortunately, sensors used nowadays to measure this magnitude are quite expensive. The most widely used are the so-called pyranometers, with an average cost of between 8000 SEK to 10000 SEK, and solar reference cells, which can be quite cheaper (1000 SEK), but also can be the most expensive devices on the market depending on the features they have (some reference cells cost 20000 SEK).In this thesis, a solar irradiance sensor based on the treatment of a current generated by a silicon photodiode has been designed, built and calibrated. The signal generated by the device is a voltage that has been obtained by means of a current-to-voltage converter amplifier stage. Once the construction of the circuit was completed, it was tested on the roof of Hall 45 located in the University of Gävle. The testing was carried out on 13, 14 and 15 May 2019, and it consisted in the comparison of the signal generated by the new device and the signals generated by a pyranometer and a solar cell.The result is a device priced at 200 SEK, which shows acceptable levels of accuracy during central daylight hours but shows a strong angular dependence on incident light during sunrise and sunset.

This master thesis was performed for the consulting firm WSP in collaboration with the think tank Besmå. The main aim of the thesis was to examine if photovoltaic/thermal solar systems (PV/T-systems) is suitable for single family houses in Sweden and if it can be a more viable option than photovoltaic systems based on economical and energy performance aspects. The thesis also examines if the owner of a single family house with existing solar panels can benefit from installing an intercooler and a heat-exchanging system that could add the untapped heat of the panels to the house’s heating system. This would decrease the solar panel temperature, thus increasing their efficiency and electricity production. It also examines the possibility of PV/T-systems playing a role in fulfilling the increased energy performance regulations placed upon contractors today, by reducing the primary energy number (primärenergitalet). To achieve these objectives the heat demand of a typical house in Sweden was simulated in VIP Energy based on a real house in Gothenburg which has a photovoltaic system. A modell for electricity production of a solar cell which included the temperature dependency was created in Matlab and a modell of a PV/T-system was created in Simulink. From these models and real data from the existing house and energy system, total production of heat and electricity was acquired. The results showed that the intercooler can enhance the solar cell performance but a life cycle cost analysis found that it was not a neconomically viable option due to its excess cost. It also showed that the PV/T system can be a suitable choice for single family houses in Sweden under certain conditions, mainly depending on uncertain price points. It did enhance the total energy performance of the house in comparison to solar cells but was only economically viable (from a life cycle perspective and not initial cost) when the main heating system consists of an electric heater. Surprisingly, it was also found that smaller PV/T-systems of 5 square meters of module area can yield a better life cycle cost than solar cells, even when the main heating system is a heat pump. Lastly, it was found that a PV/T-system can act as a viable option when building real estate as a method of lowering the primary energy number, assuming a stable and economically competitive price point and that investing in large scale systems leads to a lower price per produced unit of energy and unit of area of modules.

The offshore wind potential of the Caribbean Sea has barely been exploited. Currently, the offshore wind power industry in Latin America and the Caribbean region is still at very early stages, leaving aside an important resource that otherwise could contribute to satisfy the growing energy demand of the zone. In this study the possibilities arising from a massive exploitation of the wind resource in the Caribbean Sea are assessed. The objective is to investigate if the resources contained in it would be sufficient to satisfy the energy demand of Latin America and the Caribbean, which is foreseen to be about 1900 TWh/year by 2020. To address this question, the “Infinite wind farm” concept is used as a simple way to model the meteorological behaviour and the wind speed in the area. The model is utilized in combination with the bathymetric data of the Caribbean Sea and with a simple economic analysis, to evaluate what the requirements to satisfy the energy demand would be in terms of area, number of turbines, and levelized cost of energy (LCoE). The assessment is performed utilizing different turbine sizes, and inter-turbine separations to find the combination that minimizes the LCoE. It is found that the energy demand of Latin America and the Caribbean could be satisfied using only 125000 km2 (4.5% of the total Caribbean Sea area) of waters shallower than 25m at a cost of 69 €/MWh, if the turbines were separated 6.5D from one another and if they had a rotor diameter of 250m. In that case, 47760 turbines should be installed using only conventional monopile foundations.

This report aims to study how the indoor climate in a conference room can be improved by the use of phase change material (PCM). The study includes an experiment where 40 kg of salt hydrate based PCM was placed within a conference room located in an office in the city of Uppsala, Sweden. The experiment resulted in a decrease in the peak temperature with respect to the internal heat gains in the conference room and a slower temperature increase with PCM implemented. The report concludes that PCM can improve the indoor climate in regard to its ability to limit the temperature fluctuation. The study also contains modelling and simulation over the office and conference room in the program Trnsys. This was carried out to study how the temperature and cooling demand in the conference room and office respectively would change with a larger implementation of PCM. When 106 kg of PCM was simulated to be implemented in two of the conference room walls, the specific peak temperature was on average decreased with 0.17 °C/kW during the year. Furthermore, a decrease in the cooling demand with 16 % was achieved when implementing 1 208 kg of PCM in the internal walls of the office. This study shows that there is potential for reducing the cooling demand in the building through an implementation of PCM. Further studies with a more detailed model of the office is recommended before deciding upon if and where PCM should be implemented.

Energy security is a dynamic term with many alterating aspects, some more frequently used than others. Furthermore, humankind is becoming increasingly dependent on energy to sustain today's modern lifestyle and therefore the topic of energy security is becoming more important than ever. The trend of validating energy security is also expanding from an exclusively national context to the inclusion of, for example, the operations of a single organization. One of these organizations is the housing company, Uppsalahem, with their ambition to transform their energy system in line with their aspiration to reduce environmental impact and assure that it withstands the threats of tomorrow. This thesis aims to explore the adaptation of energy security validation from a national perspective to a company perspective with Uppsalahem as the main actor. With this in mind, the validation methodology was constructed. It included a risk analysis, indicators of energy security and a correlation analysis. The combination of these three were selected with the ambition to shed light upon several aspects of energy security. Uppsalahem's electrical and heat supply systems were then subjected to the validation and the results implied that Uppsalahem is situated in a state of dependency with its suppliers. Therefore, it is in Uppsalahem's best interest that their operations are sustained and external and internal defects are avoided. This thesis presents serveral measures that can be implemented in order for Uppsalahem to minimize its dependecy on external suppliers as well as reduce the risk of malfunction within its internal operations.

Energieffektivisering inom bostäder är viktigt för att nå bestämda mål inom den Europeiska unionen, däremot kommer inte en bostadsägare att investera i energieffektiva åtgärder om de inte är lönsamma. Detta arbete kommer att undersöka energibesparingen och lönsamheten av att införa olika förbättringsåtgärder på ett lättbetonghus i Söderhamn vilket är studieobjektet i arbetet. Syftet är att undersöka byggnadens energibalans och hur olika åtgärder påverkar energianvändningen, upplevelsen av inomhusklimatet och driftkostnaden. Studieobjektet genomgick en energikartläggning för att sedan undersöka olika förbättringsåtgärder. Kartläggningen var utförd med simuleringsverktyget IDA Indoor Climate and Energy för att konstruera en referensmodell som inkluderade alla insamlade data från studieobjektet. Tidigare forskningsstudier inom området användes som vägledning till val av förbättringsåtgärder på studieobjektet. Energiförändring utav åtgärderna användes sedan i en kostnadskalkyl som var utförd med annuitetsmetoden för att åstadkomma den årliga kostnadsbesparingen vid installation för var och en av åtgärderna. Koldioxidhalten mättes i början av projektet för att undersöka luftkvalitén i byggnaden och om den behöver åtgärdas. Studieobjektets primärenergital blev 148 kWh/(m2·år) vilket var 43 % högre än Boverkets byggreglers energikrav för småhus. Byggnadens värmebehov var 18 209 kWh/år och kunde minskas med 42,7 % vid installation av ett åtgärdspaket och då var primärenergitalet 109 kWh/(m2·år). De tre mest energieffektiva åtgärder var att tilläggsisolera ytterväggar, isolera taket och minskning av inomhustemperaturen. Den mest kostnadseffektiva av enskilda åtgärder var att isolera taket ifall övervåningsutrymmet utnyttjades och att isolera källaren var den minst lönsamma av besparingsåtgärderna. Ventilationsproblemet i byggnaden kunde åtgärdas med installation av ett FTX-system som använder luftflödet 0,35 l/(s·m2) och 0,1 l/(s·m2) när inga personer är i byggnaden. Att komplettera uppvärmningen med en värmepump var en lönsam investering men ökade primärenergianvändningen och gör byggnadens energisystem mer komplext. Det rekommenderas att isolera klart taket ifall boende har intresse av att utnyttja övervåningsutrymmet. / Energy efficiency in dwellings is crucial in reaching goals set within the European Union, but homeowners won’t invest in energy-efficient measures unless it is cost-effective. This study is going to investigate the energy savings and cost-effectiveness of different renovating measurements for a light-concreate house in Söderhamn. The aim is to investigate the building’s energy balance and how renovating measurements affect the energy use, the indoor climate and the operating cost. An energy audit was performed on the building for the purpose of investigating the various measurements. The audit was achieved with IDA Indoor Climate and Energy simulation tool, which was used to construct a reference model that included data from the studied building. Previous research in the field were used for selecting the renovating measurements used in this study. The results of the simulations were then used to carry out a cost analysis with the equivalent annual cost method to evaluate the annual cost saving for each measurement. The carbon dioxide level was measured in the beginning of the project to investigate the indoor air quality in the building and if it needed to be addressed. The primary energy use of the building was 148 kWh/(m2·year), which was 43 % more than Building regulations energy requirements for single-family households. The heat demand was 18 209 kWh/year and could be reduced by 42,7 % when installing a created renovation package and resulting in the primary energy use of 109 kWh/(m2·year).  The three most energy efficient measures were adding extra insulation on external walls, insulating the roof and decreasing the indoor temperature level. The most cost-effective measure was to insulate the roof if the upstairs area were heated and insulate the basement walls was the least cost-effective of the energy efficient measures. The ventilation problem was fixed with installation of an FTX system that switched to an air flow of 0,35 l/(s·m2) to 0,1 l/(s·m2) during unoccupancy. Complementing the heat demand with a heat pump was a cost-effective measure but did increase the primary energy use. It is recommended to finish isolating the roof if the family is interested in using the unoccupied space.

The increasing amount of renewable energy in the power system have led to new challenges to balance supply and demand in the electric grid. To maintain the balance in the power system the system operator can activate power reserves to restore the balance at a frequency deviation. Today these reserves consist exclusively of hydropower in Sweden. With more volatile power generation new types of technologies to provide these reserves are desirable. The aim of this master thesis is to investigate the technical potential for using wind power, demand response and energy storage for automatic frequency control in the Swedish power system. The thesis examines the performance of the different technologies to see if they meet the technical requirements for delivering reserves set by the TSO. Moreover, the available capacity from the technologies throughout the year are estimated. The results show that all three technologies potentially could be used for frequency control. However, the technical requirements are not always fulfilled. In order to enable new technologies to provide power reserves some of the requirements needs to be modernized. Generally, demand response proved to have the largest available capacity for frequency control today. The study shows that demand response from industries and electric heated households could potentially provide all automatic frequency control. Modern wind turbines can be used for frequency control and for down regulation of the frequency the potential is considerable. Energy storages are not yet widely used in Sweden but with reduced costs they can play an important role in regulating the frequency in the future.