Four solar cells dominate the Swedish market today and are divided into two groups; first generation and second generation. The first generation involves of two silicone solar cells called mono-and multicrystalline solar cells. These solar cells were, as the name indicates, first on the market and today receive the highest efficiency. Due to high manufacturing costs, the second generation was developed which became thin film solar cells. The two most common solar cells in that generation are CdTe and CIGS, which account for about 20 percent of the solar cell market today while the first-generation accounts for the remaining 80 percent. Going towards a sustainable future it’s important and clear that both companies, cities and countries are ready meet the challenges. The solar cell technology has gained high confidence to bring in sustainable electricity production. Investors in Sweden experience the lack of a valuation concept from an environmental perspective between the solar cells on the Swedish market. The study has examined how the four different solar cells affect different environmental categories and which materials in the solar cells that are the most critical. By simulating the electricity production for a year with Gothenburg's solar radiation, the amount of electricity that could be used or sent to the grid was obtained. Where the silicon solar cells that have the highest efficiency also received the most electricity per square meter of solar cell. After producing electricity production and electricity consumption, the energy repayment period was calculated. Through LCA, 11 different environmental categories were developed to analyze different areas that are affected by solar cell production. Aquatic ecotoxicity of the marine environment was the environmental category that was most affected by the production for all four solar cell types. From the environmental category Global Warming, the amount of carbon dioxide equivalents was studied and then a payback time was calculated. Solar cells generally have three different phases; manufacture, operating and waste. The use phase is considered to be almost emission-free, the waste phase is relatively new for solar cell technologies. This is because no large waste streams have come than when the first major investments took place only in the nineties. The solar cells need different techniques depending on the type. The strategies should be different as different parts should be recycled and reused as far as possible. Due to the fact that there is unstable waste management, this phase has not been studied but only the manufacturing phase.   A square metered solar cell was analyzed. For photovoltaic production in Europe, multicrystalline solar cell panels pay back the carbon dioxide equivalents after 11.5 years, while monocrystalline solar cell panels pay again after 14.3 years, ie after about half the life. CdTe paid the carbon dioxide equivalents fastest, after 2.2 years, and CIGS after 3.6 years. This means that the thin-film solar cells have the fastest time to get minus emissions. It is not justified to invest in solar cells manufactured in China when operating in Gothenburg, only after studying solar cell production. When the repayment period for carbon dioxide equivalents has been calculated, a Nordic electricity mix has been calculated with, depending on which electricity mix is ​​chosen, it either gives reasons to not invest or to invest in solar cells. It is therefore important to be clear about what use the solar cells will have and which electricity is actually replaced before investors decide whether solar cells are the right energy source to invest in.

Brazil is one of the largest biomass producers in the world, thus it has a huge potential for biogas production across all its territory. Nowadays, biogas production remains largely unexplored, representing just a small fraction of its potential. The adoption of biogas technologies has grown over the past years, but it is unevenly distributed across Brazilian states. This master thesis investigates the conditions under which the widespread diffusion of biogas technologies can be enabled in the Brazilian context by looking at the factors that influence the adoption of biogas technologies and why it differs across the Brazilian territory. Technological innovation systems (TIS), societal embedding, and diffusion of innovation theory are combined in the theoretical framework to create a broad understanding of the diffusion process of biogas technologies in Brazil. While TIS focusses on what are the functions been performed within the system, Societal embedding contributes to the understanding of why technological diffusion may not happen in the same way in different regions and how technologies are rooted in society. Diffusion of innovation theory adds to the importance of individual choices and strategies in the adoption of technologies. A comparative case study was design between the states São Paulo and Paraná. 16 semi-structured interviews served as the main research instrument with the support of document studies. When looking at the factors that could impact the adoption of biogas technologies the presence of specialized actors that can offer technical support to the implementation of projects locally proved to be positive considering that biogas technologies are still novel in Brazil. The unreliability of the energy grid in rural regions also favours the adoption of biogas technologies for electricity generation in agriculture properties that can combined waste treatment with energy security. Access to financial and human resources is still the largest barrier for the diffusion of biogas technologies. Financial institutions are at large unprepared to offer good conditions for the implementation of biogas projects, mainly because they do not understand the singularities of these projects. The adoption of biogas technologies in the case studies was mainly dictated by the economic activities in place, which shaped the view on biogas technologies. The complexities of the regulatory environment in Brazil could explain why electricity generation is still the main application of biogas technologies as the electricity market is regulated at national level while gas markets are the responsibility of individual states. When biogas technologies are portraited as a tool for sustainable development, other advantages of these technologies are highlighted – environmental and social benefits such as waste treatment and job creation – creating a better claim for biogas technologies which could boost adoption.

Energy storage is an important key for future energy systems. A most common form of energy storage is the battery. However, producing a battery is not very efficient nor sustainable. Therefore, every part and every machine in the manufacturing process must be measured and analysed. The next step is to find solutions of how to make each part more effective. The purpose of the thesis was to analyse the power consumption of a battery cycling machine and log the temperature changes. The quality of a battery cell is tested by charging and discharging the cell to different state of charge in this machine. The results showed a lower efficiency during standby state, which is a state when the machine is not used yet is still running. The efficiency increased during charge and discharge of the cells. Moreover, with enough cells discharging at the same time, the machine could produce electricity. This would also mean that the cells charge at the same time and lead to a volatile load profile. The temperature increased slightly during charge and discharge but not above the upper limit. In summary, by scheming the usage of the machines adapted to the number of cells, some machines can be turned off instead of being in standby state. All the machines should be connected to each other in order to exchange excess electricity between them. These solutions can lower the power consumption and make the process more efficient.

The purpose of the thesis is to contribute to grid planning and public debate about how the electric power system can cope with electrification and decarbonisation. The thesis is based on the assumption that Sweden, in accordance with the climate goals, will achieve climate neutrality by 2045. Based on a literature review, an analysis is made of how different scenarios predict the future national electricity demand up until 2045 and identifies the underlying drivers for changes in electricity demand. A more detailed analysis based on results from a literature review and interviews with industry representatives is made for four chosen regions, Norrbotten, Västra Götaland, Stockholm and Skåne. For each region, estimates are made of how high the electrification potential is in the industrial, transport, residential and service sectors. The prerequisites for the electricity grid to handle the identified electrification potential, in terms of grid capacity, have been analysed in order to highlight what challenges there are for large-scale electrification to be a key factor in achieving the climate goals. The general belief in the studied scenarios is that the national electricity demand will increase until 2045. The investigated scenarios predict increases resulting in an annual national electricity demand of up to 207 TWh in 2045, corresponding to an increase of almost 60 %. The most significant increases are due to decarbonisation in the industry and transport sector. The regional analysis shows significant electrification potentials in the investigated regions. A few industries stand out with dramatic increases, Borealis AB in Västra Götaland shows an electrification potential of 8 TWh and 1 000 MW and SSAB in Norrbotten shows an electrification potential of 9 TWh and 900 MW. Significant electrification potentials in the transport, residential and service sectors have been identified in metropolitan areas, i.e. in the region of Stockholm, Västra Götaland and Skåne. The grid analysis shows that it will be challenging to increase grid capacity at sufficient speed. It is concluded that there is currently insufficient grid capacity to meet large-scale electrification, and that the grids need to be reinforced. However, the concession process for grid reinforcements is considered too slow to meet the demands that arise, primarily in the industry sector. Three ways to address this challenge have been identified: -          If the permission process for electricity grid expansion does not change and the industry is to choose the electrification route, this needs to be decided before 2030 in order for reinforcements in the electricity grid to be ensured before 2045. -          Speed up the permit process to allow shorter lead times for power grid expansions. -          The industry choose another route for decarbonisation than electrification. The overall conclusion is that new approaches for expanding the electricity grid will be required if large-scale electrification is to be a key factor in achieving the climate goals in 2045.

The environmental Kuznets curve (EKC) hypothesis describes the relationship between economic growth and environmental degradation through an inverted U-shape where environmental degradation first increases with economic growth, to later stagnate and decline as economic growth reaches specific threshold limits. The aim of this study is to investigate the EKC hypothesis when environmental degradation is measured through a country’s renewable energy implementation. This is achieved through multiple scatterplots and a Granger causality test, and the key finding are (1) that a consensus regarding the relationship between economic growth and energy consumption is missing, (2) that countries seems to significantly increase their consumption of renewable energy between US$ 30 000 - 50 000 when measured in real GDP per capita, (3) that the theoretical shape of the EKC holds for most countries, (4) a unidirectional causality running from economic growth to fossil fuel consumption for a panel of developing countries, and (5) a unidirectional causality running from economic growth to both fossil fuel and renewable energy consumption as well as a unidirectional causality running from renewable energy consumption to fossil fuel consumption for a panel of developed countries. When the EKC is measured though a country’s renewable energy implementation the hypothesis seems to hold for most countries. However, the decrease in environmental degradation is so far limited to developed countries with smaller economies and populations. These countries also need to ensure that decreases in environmental degradation is a result of underlying mechanisms like energy efficiency improvements and not other more counterproductive behaviors like outsourcing and deindustrialization.

To make sure that a dam is safe it is important to have good knowledge about the energy dissipation in the spillway. Physical hydraulic model tests are reliable when investigating how the water flow behaves on its way through the spillway. The problem with physical model testing is that it is both expensive and time consuming, therefore computational fluid dynamics, CFD, is a more feasible option. This projects focuses on a spillway located in Sweden that Vattenfall R&D built a physical model of to simulate the water discharge and evaluate the energy dissipation in order to rebuild the actual spillway. The main purpose of this project is to evaluate if the physical hydraulic test results can be reproduced by using CFD, and obtain detailed results about the flow that could not be obtained by physical testing. There are several steps that need to be completed to create a CFD-model. The first step is to create a geometry, then the geometry needs to be meshed. After the meshing the boundary conditions need to be set and the different models, multiphase model and the viscous model, need to be defined. Next step is to set the operating conditions and decide which solution method that will be used. Then the simulation can be run and the results can get extracted. In this project two CFD simulations were performed. The first simulation was to be compared with the physical hydraulic model test results and the second CFD simulation was of the rebuilt spillway. The results proved that the physical model test results could be recreated by using CFD. It also gave a better understanding of how the energy dissipation was in the spillway and indicates that the reconstruction of the actual spillway was successful since the new spillway both had a higher water discharge capacity and better energy dissipation.

Improved industrial energy efficiency is viewed as an important means in the reduction of CO2 emissions and climate change mitigation. Various energy efficiency measures for improving energy efficiency exists, but even evaluated as cost-effective, there seems to be a difference between the energy efficiency measures that theoretically could be undertaken and which measures that actually are realised. On the other hand, industrial energy efficiency measures might yield extra effects, denoted as non-energy benefits, beyond the actual energy savings or energy cost savings. Based on interviews and a questionnaire, results showed that the Swedish industrial firms studied had observed various non-energy benefits. However, few of the non-energy benefits observed were translated into monetary values and included in investment calculations. Results indicated that this non-inclusion could be explained by lack on information on how to measure and monetise the benefits, but even if not translated into monetary values, some of the non-energy benefits were sometimes used qualitatively in investment decisions. The utilisation of the benefits seemed to depend on the type and the level of quantifiability among the perceived benefits. This thesis has also explored energy efficiency measures and non-energy benefits for a specific industrial energy-using process – compressed air. A literature review on energy efficiency in relation to compressed air systems revealed a large variation in which measures that could be undertaken to improve energy efficiency. However, few publications applied a comprehensive perspective including the entire compressed air system. Few non-energy benefits of specific energy efficiency measures for compressed air systems were identified, but the study provided insights into how non-energy benefits should be studied. This thesis suggests that energy efficiency and non-energy benefits in compressed air systems should be studied on specific measure level to enable the observation of their effects. However, the studies also addressed the importance of having a systems perspective; the whole system should be regarded to understand the effects of energy efficiency measures and related non-energy benefits.

Liquefied natural gas (LNG) cold utilization in small scale regasification stations is a novel topic in the industry, while such systems have been proven feasible in large scale LNG facilities. Cold recovery and utilization in LNG regasification facilities would increase the thermodynamic efficiency and reduce cold pollution. The aim of the study is to analyze the possibility to apply industry-proven thermodynamic cycles in small scale satellite regasification stations for electricity production, taking the characteristics of a real-world regasification station project in Druskininkai, Lithuania for which useful cold utilization is not currently planned. Direct Expansion (DE) and Rankine (ORC) Cycles are analyzed together with cascading using Aspen Hysys software to find the optimal solution considering thermal and exergy efficiency as well as the payback period. Thermoeconomically feasible retrofit solutions of approximately 13% thermal efficiency and approximately 17% exergy efficiency showing payback periods of 5 to 10 years and 3.3 to 6 thousand euro additional capital expenditure (CAPEX) per net kW of power production are found. Increase in complexity of thermodynamic cycles is directly proportional to both increased thermodynamic efficiencies and capital costs and the study proves that there is a limit at which increase in thermodynamic efficiency of a cycle by cascading becomes economically infeasible. Future work is suggested to improve the accuracy of the results by rigorous design to evaluate pressure drops as well as improvements in economic analysis by utilizing the discounted cash flow methodology. Sensitivity analysis of LNG physical and chemical conditions as well as ambient air could be performed whereas changes in working fluid and better engineering of the part related to intial heat exchange could improve thermodynamic efficiencies. Alternative solutions with a higher temperature heat source are also suggested.

One of the major challenges that the energy system is facing is how 100% renewable electricity generation should be designed and controlled. So far, utility-scale solar photovoltaic (PV) parks, have dominated the international market and is expected to grow in Sweden. In order for this expansion to thrive it needs to be done in a resource and system-efficient way. In this study, a methodology for a utility-scale solar guide (from Swedish 'Solbruksplan') is developed. This is done through electrical grid simulations and geographical analysis in order to find strategic locations for PV parks, without grid reinforcements, using Herrljunga municipality as a case study. The electrical grid is analyzed through power flow simulations and the geographical assessment is done using multi-criteria analysis (MCA) with a Boolean approach. Three different sizes of PV parks, 1, 3, and 5 MW, were simulated and assessed. The results show that 8.6% of the total area in the municipality, or 78,500 square meters per substation, is suitable for locating 1 MW PV parks. The majority of the grid’s substations (about 90%) also have enough capacity for a PV park of 1 MW. Furthermore, parts of the grid can host PV parks of 3 and 5 MW, but limited to the proximity of the urban areas. However, 3 and 5 MW PV parks are not suitable due to limited land availability in urban areas. The results highlight that a utility-scale solar guide can be used to effectively identify possible areas for PV parks, considering geography and grid capacity. Hence, it can function as a tool for utility companies, municipalities, PV companies and land-owners to find resource and system-efficient locations for PV parks. / Solbruksplaner för system- och resurseffektiv utbyggnad av solelproduktion

Sweden aims to achieve climate neutrality by 2045. The need to immediately reduce greenhouse gas emissions in order to achieve climate targets affects industry directly. The pulp and paper sector is responsible for more than 50% of industrial energy use in Sweden. Increased energy efficiency is expected to contribute significantly to the reduction of primary energy use. The recovery and utilisation of industrial excess heat (IEH) has been identified as an important potential contribution to energy efficiency in industry. Previous research based on top-down studies has estimated the availability of IEH for entire sectors, and bottom-up results for many case studies are available. While top-down studies lack detailed information on the profile of the excess heat available, bottom-up studies have limited coverage. Detailed information about excess heat amounts and temperature levels is required for the assessment of the potential of the various heat recovery technologies that are available.  The aim of this thesis is to present, in a series of steps, methods to systematically analyse an industrial process to obtain a detailed profile of the excess heat available under various process conditions, to aggregate results that can be generalised to whole industrial sectors, and to obtain IEH recovery potentials using different technologies. The assessment of the utilisation options for IEH recovery is complemented with an analysis of system aspects that could affect profitability and global greenhouse gas (GHG) emissions. An energy-targeting procedure combined with optimisation has been applied to six case studies of kraft pulp and paper mills in Sweden. This method obtained IEH profiles that were used in a regression analysis to estimate the IEH availability and electricity generation potentials from low and medium temperature IEH using organic Rankine cycles (ORC). A comparison of profitability and global GHG emissions between ORC electricity generation using IEH and small-scale combined heat and electricity (CHP) production is presented for three energy markets. The results show that there is a potential to increase electricity generation from low and medium temperature IEH by 7–9% in the kraft mills in Sweden, depending on the level of process integration considered. The utilisation of low and medium temperature IEH for electricity generation has the potential to reduce global GHG emissions in all the energy-market scenarios considered, but if biomass is considered a limited resource, district heating (DH) deliveries can achieve higher global GHG reductions. ORC electricity generation from low and medium temperature IEH is economically viable and showed overall better profitability and GHG emissions reductions than small-scale CHP using ORCs. The economic feasibility of ORC electricity generation is less affected by external conditions and uncertainties than direct DH deliveries. / Sverige siktar på att uppnå klimatneutralitet till 2045. Behovet av att omedelbart minska utsläppen av växthusgaser för att nå klimatmålen påverkar industrin direkt. Massa- och papperssektorn står för mer än 50% av den industriella energianvändningen i Sverige. Ökad energieffektivitet förväntas i hög grad bidra till att minska primärenergianvändningen. Återvinning och utnyttjande av industriell överskottsvärme (IÖV) har identifierats som ett betydande potentiellt bidrag till energieffektivitet i industrin. Tidigare forskning baserad på top-down studier har uppskattat tillgängligheten av IÖV för hela sektorer eller regioner, och bottom-up resultat för många fallstudier finns tillgängliga. Medan top-down studier saknar detaljerad information om profilen för tillgänglig överskottsvärme, har bottom-up studier begränsad täckning och precision. Detaljerad information om överskottsvärmemängder och temperaturnivåer krävs för att bedöma potentialen hos flera värmeåtervinningstekniker. Denna avhandling syftar till att i en serie steg presentera metoder för att systematiskt analysera en industriell process för att erhålla en detaljerad profil av tillgänglig överskottsvärme under olika processförhållanden, för att aggregera resultat som kan generaliseras för hela industrisektorer, och att erhålla återvinningspotentialer för industriell överskottsvärme med hjälp av olika teknologier. Bedömningen av olika möjligheter att använda industriell överskottsvärme kompletteras med en analys av systemaspekter som kan påverka lönsamhet och globala växthusgasutsläpp. Ett energimålsförfarande kombinerat med optimering har tillämpats på sex fallstudier av massa- och pappersbruk i Sverige, med produktion baserat på sulfatmassa. Med denna metod erhålls IÖV-profiler som används i en regressionsanalys för att uppskatta tillgängligheten av IÖV och potentialen för elproduktion från låg- och medeltempererad IÖV med organiska Rankine-cykler (ORC). En jämförelse av lönsamhet och globala växthusgasutsläpp mellan elproduktion med ORC, där IÖV utgör grunden, och småskalig kombinerad värme och el (KVV) produktion presenteras för tre energimarknader. Resultaten visar en potential att öka elproduktionen från låg- och medeltempererad IÖV med 7% till 9% i sulfatmassabruken i Sverige, beroende på graden av processintegration som beaktas. Användningen av låg- och medeltempererad IÖV för elproduktion kan potentiellt minska de globala växthusgasutsläppen i alla övervägda energimarknadsscenarier. Om biomassa betraktas som en begränsad resurs, kan emellertid direkta fjärrvärmeleveranser uppnå högre globala minskningar av växthusgaser. ORC-elproduktion från låg- och medeltempererad IÖV är ekonomiskt lönsam och visade överlag bättre lönsamhet och minskade växthusgasutsläpp än småskalig ORC-kraftvärme. Den ekonomiska genomförbarheten av ORC-elproduktion påverkas mindre av yttre förhållanden och osäkerheter än fjärrvärmeleveranser.