The aim of this thesis is to apply and evaluate potential forecasting models for solar power production, based on data from a photovoltaic facility in Sala, Sweden. The thesis evaluates single step forecasting models as well as multiple step forecasting models, where the three compared models for single step forecasting are persistence, autoregressive integrated moving average (ARIMA) and ARIMAX. ARIMAX is an ARIMA model that also takes exogenous predictors in consideration. In this thesis the evaluated exogenous predictor is wind speed. The two compared multiple step models are multiple step persistence and the Gaussian process (GP). Root mean squared error (RMSE) is used as the measurement of evaluation and thus determining the accuracy of the models. Results show that the ARIMAX models performed most accurate in every simulation of the single step models implementation, which implies that adding the exogenous predictor wind speed increases the accuracy. However, the accuracy only increased by 0.04% at most, which is determined as a minimal amount. Moreover, the results show that the GP model was 3% more accurate than the multiple step persistence; however, the GP model could be further developed by adding more training data or exogenous variables to the model.

The concern of climate change and Greenhouse Gas emission have increased national consideration toward energy efficiency. Despite noticeable action which have taken by EU cities and Sweden government to mitigate the climate change, there is still shortage in appropriate energy measurements in old residential buildings. Due to the fact that a large share of residential buildings in Sweden have constructed more than 40 years ago, most of them need energy renovation  to enhance efficiency and saving more energy. In order to encourage home owners toward energy efficiency renovations, some cost effective measurements have to introduce to people with the view of effect on property value.  To this end, 50 detached houses and villas in Kronoberg County in Sweden have been chosen and analyzed to identify how renovation can increase the property value. These houses have been set in different categories by location, heating system, deep renovation, energy and aesthetic renovation. After that, compares the sold prices and biding prices for each category. Moreover, it analyses the people behavior toward renovation to see how can motive people to adopt necessary energy efficient renovation. This research also shows the current situation of building renovation, the most favourite renovation which are adopted by people as well as providing information about the factors affect the value of the house after renovation.

An existing solar-powered water pumping system located in Mutomo, Kenya has beenevaluated in this paper. The requirement for this system is to produce a minimum of25m³ water per day throughout the year.The aim of this thesis is to investigate theperformance of the currently installed system and find a suitable replacement in termsof efficiency and economic viability. In order to acquire the necessary knowledge forthis project, a literature study was carried out to analyse the research within the area.Three simulation models were created which all include an electric motor driven by aphotovoltaic array and are connected to a submersible groundwater pump. Allmodels utilise space vector pulse width modulation. One model of an inductionmotor that represents the currently installed system, one induction motor thatdelivers a minimum of 25 m³ water per day, and one model of a permanent magnetsynchronous motor for comparison. Simulations using weather data, representing anaverage day for each month of the year were carried out. It was shown that thecurrently installed system does not fulfil the requirement of producing 25 m³ waterper day, and in addition produces a significant amount of energy that can not beutilised. It was also shown that the efficiency of the permanent magnet synchronousmotor was superior to the induction motors. In order to compare the systems interms of economic viability, price quotations from world leading manufacturers wereacquired. The results of the economic comparison show that the superior efficiencyof the permanent magnet synchronous motor was not enough to compensate for thehigher investment cost.

There is a challenge to feed an increasing world population. Simultaneously, as more people rely on food production, ensuring a sustainable food production becomes more important. In two of the United Nations’ seventeen sustainable development goals food is mentioned, and one of the more specific targets regards making public procurements more sustainable. There are however challenges with regards to how to reduce a Swedish public procurement’s environmental impacts. This is due to some fundamental principles every Swedish public procurement must follow. This thesis examines the environmental impacts of two public procurements of food, regarding global warming, acidification and eutrophication. It also examines whether calculating food’s environmental impacts per serving or per kg is the more representative approach. Lastly, this thesis examines how the environmental impacts of a public procurements of food can be reduced. Consequently, a methodology of how to minimize the environmental impacts of a procurement is presented. Firstly, the results show that the environmental impacts per servings and per kg differ. One procurement has approximately 50-60% higher environmental impacts compared to the other when measured per serving, but approximately 2-9% lower impacts when measured per kg. The authors argue that representing the environmental impacts per serving is more accurate, since it is more correlated to nutritional values. Secondly, the results show that the environmental impacts for minimizing each environmental impact category differs.

Att minska energianvändningen är lika mycket ett globalt mål som ett nationellt mål. Sverige har som mål att öka effektiviseringen av energianvändningen med 20 % fram till år 2020. Det gör att nästan alla sektorer påverkas och inte minst bostads- och servicesektorn som står för nästan 40 % av Sveriges energianvändning. Ventilationssystem är en av de saker som kan bidra till energibesparingen. I den här studien har en nybyggd grundskola simulerats avseende energi och komfort där olika ventilationssystem testats för att se vilket system som är mest lönsamt ekonomiskt, energi- och komfortmässigt. Det som skiljer ventilationssystemen åt är de olika typerna av flödesreglering. Två huvudtyper av ventilationsflödesreglering har testats: ”Variable Air Volume” = Luftflödet varierar efter behovet (VAV) och ”Constant Air Volume” = Konstant luftflöde (CAV). Byggnaden, som är välisolerad och har tung stomme, har även simulerats med ökad personbelastning för att se hur det påverkar ventilationssystemet. Metoden som används för att utföra arbetet är en simuleringsstudie av komparativt slag, där datorprogrammet IDA ICE 4.8 har använts för att modellera byggnaden och utföra simuleringarna. Modellen som har simulerats efterliknar delar av grundskolan Stigslundsskolan i Gävle, i både uppbyggnad, ventilation och användningsgrad. Data har samlats in från konsultföretaget Rambolls databaser med information om projekteringen av skolan och genom personlig kommunikation. Simuleringen av ett skolår har utförts och ett schema för personbelastningen har ställts in för varje sal för att efterlikna det schema som eleverna går efter i dagsläget. Resultatet av simuleringarna visade att VAV -ventilationssystemet som efterliknar det projekterade fallet väl täckte ventilationsbehovet, använde mindre energi än CAV-systemet och skapade ett mycket bra termiskt klimat i byggnaden. Resultatet visade också att ökad personbelastning hade stor inverkan på ventilationssystemet, och medförde bland annat att återbetalningstiden för VAV-systemet ökade från 11 till 30 år. / To reduce the energy use is as much a global goal as it is an international goal. The Swedish goal is to increase the efficiency of energy use with 20 % by year 2020. This means that almost all the sectors are affected, that includes the housing and service sector which accounts for almost 40 % of Sweden’s energy use. The ventilation system is one thing that can contribute to saving energy. In this study a new built primary school has been simulated, regarding energy use and thermal comfort, where different ventilation system has been tested to determine which system are the most profitable in economically, energy and comfortably. The ventilation system different in the flow control. Two main types of flow control have been tested: Variable Air Volume (VAV) and Constant Air Volume (CAV). The building, which is well insulated and has a heavy body has also been simulated with increased personal load to see how it affects the ventilation system. The method used to perform the work is a comparative type simulation study. The computer program IDA ICE 4.8 has been used to build the model and do the simulations. The model that has been simulated resemble the primary school Stigslundsskolan in Gävle in both construction, ventilation and degree of use. Data has been collected from the consulting company Ramboll’s database with information on the planning of the school. Personal communication has also been used to collect information. The simulations have been performed for a school year and a schedule for the personal load has been set for each hall to imitate the schedule that the students are following today. The result of the simulations showed that the VAV ventilation system, which resemble the planned case, cover the ventilation requirements, uses less energy than the CAV system and create a very good thermal climate in the building. The result also shows that the increased personal load had a great influence on the VAV ventilation system and increased the repayment period from 11 to 30 years.

In this study, the financial and economic viable of perovskite-SHJ tandem solar cells were determined using a detailed bottom-up cost model and energy-yield calculations. Attention to specific advancements in perovskite solar cell layer technology and large-scale deposition have been taken into account to create a realistic, viable commercial scale option for tandem production. A reference tandem technology is used to determine the overall manufacturing cost and minimum sustainable price. Models used show that the tandem technology has the potential to be cost competitive with existing silicon technology given the uncertainty and sensitivity of the values used in this study. It was examined further how non-STC energy yield and service life contributes to the overall economic viability of the tandem module within residential, commercial and utility scale of application. Given the reference tandem module, it is expected to be competitive at the residential level with existing silicon technology if perovskite layers' service life is greater than 20 years. In commercial and utility application, the tandem model is not economically viable due to the reductions seen in the area- and project-related installation costs for existing technology. This thesis concludes by presenting the current limitations in perovskite technology that would inhibit adaptation of this into commercial-scale production and presents alternative applications in which tandem modules would be more favourable.

In this study, it was investigated how individual households could manage security of supply during an outage by installing a local energy system that could operate independently from the electricity grid. By installing local renewable off-grid energy systems, households could guarantee an uninterrupted supply of energy even during an outage on the electricity grid, while also increasing their energy autonomy during normal circumstances. The results showed that managing an outage during summer was fairly easy. Due to high electricity production, a small energy storage was enough to manage an outage during summer. However, managing an outage during winter was more critical. During winter, the systems needed to be almost fully reliant on the energy storage. This significantly increased the cost of these systems. Due to the high cost for the energy systems today, it was not considered a feasible solution to improve energy security at a national level. However, at a local level, this was considered to have the potential to improve energy security. First, it could to be of interest for people who already have installed solar panels, who could add a battery and thereby be able to manage an outage during summer. Second, it could be of interest for people who are more exposed to outages or have a low trust in the system to work properly. Lastly, this could be of interest for actors for whom backup energy is important, for instance for the industry.

SAMMANFATTNING Medvetenhet och oro kring miljöeffekter från utsläpp av växthusgaser och de minskande resurserna av icke förnybara energikällor har ökat de senaste årtiondena. Utvecklingen av ny teknologi för förnybar energi har drivits fram globalt som ett svar på denna oro. Det har skett stora framsteg i produktion av el och värme från sol, vind, hav, vattenkraft, biomassa, geotermiska resurser, biobränslen och väte. Följaktligen har utvecklingen av energi-lager blivit en viktig del för integration av förnybar energi i systemen. Det är gynnsamt för hela försörjningskedjan, för pålitlighet och bättre stabilitet i leveranser och distribution, och för ökad el-kvalitet. I uppsatsen undersöks en optimal energidesign för ett kombinerat system med vattenkraft och vindkraft inklusive ett lager i form av en damm. Vatten som pumpas upp till lagret har en stor och balanserande potential för att få in en högre grad förnybar energi i energisystemen. Detta är nödvändigt då dessa energikällor är intermittenta och variabla till sin natur. Ett av de studerade objekten är ett vattenkraftverk med pumpad damm, Tehri i Uttarakhand, Indien. Systemets totala verkningsgrad om 93 % diskuteras utifrån förluster såväl som potentialen för vind och dess inverkan. Vind-data är hämta från National Institute of Wind Energy (NIWE) och har analyserats med programmen MATLAB och WindPro. Det slutligen valda området för exploatering av vindkraft blev Ramakkalmedu, Idukki district, Kerala, Indien. Efter valet av plats valdes tre olika vindturbiner ut för analys; Siemens SWT-3.2-113 3.2 MW, Enercon E-126 4.2MW, och Enercon E-126 7.58MW. Analysen består av flera delar; vindparks-modellering, beräkning av buller-generering från vindkraften, beräkning av årlig energi-generering - Annual Energy Production (AEP), kapacitetsfaktor, vindparkens effektivitet med hänsyn tagen till lagret/dammens variation av bas-last. Resultat har erhållits från alla tre turbinerna och den övergripande slutsatsen är att kombinationen med vatten- och vindkraft med lagring av vatten som pumpas upp vid behov är en tillfredsställande metod för att möta belastningstoppar, vilket valideras av denna uppsats.   Nyckelord: pumpade vattenkraftdammar, vindkraftparker, energi lager, förnybar energi. / ABSTRACT  Awareness and concern regarding the environmental effects of greenhouse gas emissions and depletion of non-renewable energy sources has increased over the last decades. A considerable development of new technology for renewable energy has occurred globally as an answer to this concern. There has been a major progress in production of electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen. Consequently, the development of energy storages has become an imperative part, for integration of renewable energy. It is beneficial for the entire supply chain, for dependability and better stability, and for enhanced quality of electrical power. This thesis is exploring an optimal energy design for a system of pumped hydro-wind power plants including storage. Solutions with Pumped Hydro Storages have a great potential for their balancing role necessary for a higher degree of renewable energy sources, RES, in the energy systems because of the intermittent and variable nature of these sources. Tehri pumped hydro storage plant, in Uttarakhand, India is one of the objects studied in this thesis. The systems total efficiency of 93%, calculated from head losses, is discussed as well as wind potential and its impact. Wind data is obtained from National Institute of Wind Energy (NIWE) and analysed using the software tools MATLAB and WindPro. The finally chosen area explored for wind potential is Ramakkalmedu, Idukki district, Kerala, India. After selection of site within the area, three different turbines; Siemens SWT-3.2-113 3.2 MW, Enercon E-126 4.2MW, and Enercon E-126 7.58MW were considered for analysis. The analysis consists of several parts; Wind farm modelling, Noise estimation of Wind Park, estimation of Annual Energy Production (AEP), Capacity factor, Wind park efficiency with respect to the storage/reservoir´s base load variation. Results are achieved for all three turbines. The overall conclusion is that combined hydro and wind power with a pumped storage, is a satisfactory method for bulk energy store to address peak loads, which is validated by this thesis.   Keywords: Pumped Hydro, Wind farm, Energy Storage, Renewable Energy.

The renewable energy sources are the primary solution for energy demand in all the countries because it’s being harmless to the environment. In the short term, wind energy has the most potential among all the renewable energy technologies. In the European Union, Sweden is largely based on renewable energy for their energy demand. Sweden is one of the leading country in the EU where wind power has been growing rapidly. As wind turbines in recent time have been more and more commonly placed in forestal terrain in Sweden, it is of interest to know the difference in annual output compared to the flat terrain which was the earlier dominant terrain type for wind turbines. In this thesis, the difference between the two terrain types is investigated for a number of wind turbine models. This paper presents the study from the annual Vindstat report of the year 2015 and 2016. The data were accumulated in the Excel file and the terrain for turbine locations was classified using Google Earth. Finally, the power generation in both areas are compared by graphs and tables. The results indicate the difference in production according to the terrain and turbine rating. And it was a surprising finding that the difference between them is not more as we expected. Even more, further study is required to find the difference between in forest and flat wind turbines in all the aspects.

On planet Earth, fossil fuels are the most important sources of energy. However, these resources are limited and being depleted dramatically throughout last decades. Finding feasible substitutes of these resources is an essential duty for humanity. Fortunately, Mother Nature is providing us a number of good solutions for this crucial threat against our planet. Solar irradiance, wind blowing, oceanic and maritime waves are natural resources of energy that are capable of completely covering the annual consumption of all inhabitants on the Earth. In this research a set of components including “Northern Power NPS 100-24” wind generators, “Kyocera KD 145 SX-UFU” PV arrays, “Gildemeister 10kW-40kWh Cellcube” battery bank and HOMER bi-directional converter system were considered and successfully applied on HOMER tool and Particle Swarm Optimization (PSO) method. The main design goals of the presented hybrid system are to use 100% renewable energy resources in the commercial sector, where all power is produced in the immediate vicinity of the business place, adding strong advertising values to the setup. In order to supply hourly required load for a grocery store   (1000 ) in Malmö city with 115 kW peak load and 2002 kWh/d with maximum 0.1% unmet, the system was optimized to achieve minimum Levelized Cost of Energy (LCOE) and the lowest Net Present Cost (NPC). The HOMER simulation for quantitative analysis, along with a Particle Swarm Optimization (PSO) solution method is proposed and the results are compared. The results show that an optimized hybrid system with 3.12  LCOE, and power production of 28.5% by PV arrays and 71.5% by wind generators, is the best practice for this case study. / De fossila bränslena är idag de viktigaste energikällorna på jorden. Dessa resurser är dock begränsade och har utarmats i en allt högre takt under de senaste decennierna. Att hitta möjliga ersättare för dessa resurser är därför viktigt. Lyckligtvis tillhandahåller naturen ett antal bra lösningar för detta avgörande hot mot vår planet. Solstrålning, vind, havsströmmar och -vågor är naturliga resurser av energi som kan täcka hela den årliga globala förbrukningen. I den här rapporten studeras ett hybridsystem bestående av Northern Power NPS 100-24 vindkraftverk, Kyocera KD 145 SX-UFU solcellerspaneler, Gildemeister 10kW-40kWh Cellcube batteribank och HOMER dubbelriktad växelriktare. Detta modellerades och optimerades dels i mjukvaran HOMER, dels via optimeringsmetoden Particle Swarm Optimaization (PSO). Det övergripande designkravet för det presenterade hybridsystemet är att använda 100% förnyelsebar energi i en kommersiell verksamhet, där all elektricitet produceras i närhet av verksamheten, vilket kan ge tydliga marknadsföringsvärden till installationen. För att kunna möta energibehovet varje timme för en livsmedelsbutik (1000 ) i Malmö med 115 kW toppförbrukning och 2002 kWh/dag, med maximalt 0,1% ej mött behov, optimerades systemet för att uppnå minimal energikostnad (Levelized Cost of Energy, LCOE) och lägsta nettonuvärde (Net Present Cost, NPC). En HOMER-simulering för kvantitativ analys, tillsammans med en PSO-optimering, har genomförts och resultaten har jämförts. Resultaten visar att ett optimerat hybridsystem med LCOE på 3,12 SEK/kWh, där solceller står för 28,5% av kraftproduktionen och vindkraftverk för 71,5%, är den bästa lösningen för denna fallstudie.