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Blockchain is described as having endless theoretical potential. In reality however, it is hard toestablish how blockchain can be utilized and what opportunities blockchain may create. Theunclear future of blockchain constitutes a challenge for many companies. Many large incumbentsare uncertain of how to implement blockchain technology in their organization and are anxiousabout the consequences of the new technology. The purpose of this exploratory study is to evaluateblockchain applications for a district heating company in Stockholm to understand favorable areas,necessary criteria for successful implementation and how blockchain could enable new businessopportunities in the district heating market. To be able to reach the purpose of the thesis aliterature study and an empirical study were performed. The literature study is in the form of anextensive investigation about the areas of blockchain and district heating. The empirical studyincludes 17 interviews, both internal interviews with employees at Stockholm Exergi and externalinterviews conducted with professionals with knowledge about blockchain, district heating and theenergy sector. Furthermore, two workshops, in collaboration with Stockholm Exergi, wereperformed at the end of the thesis to evaluate and prioritize the developed blockchain applications.This thesis proposes 32 blockchain applications within 10 areas in the district heating industry.The applications are categorized after their potential, in three categories; green for the blockchainapplications that are valuable to investigate further, orange for the applications that potentiallycould be interesting to investigate further, and red for the applications that are not interesting toinvestigate further. Some applications focus on solving inefficiencies within district heating andsome on exploiting the benefits of blockchain. Eight applications are categorized with greenprioritization, and thus presented in more detail. To take into account that blockchain probablywill have a greater impact in the future, a future scenario was developed and used in the situationalanalysis for the applications. Furthermore, a framework was developed with the aim to be a toolfor a district heating company to utilize while considering if a blockchain implementation wouldbe beneficial, and if so, in what way. The framework is focused on district heating companies butcan be utilized by other actors as well.Our recommendation for a district heating company in Stockholm is to wait one or two yearswhile staying updated. Especially important for the companies are to stay updated on whether newblockchain standardizations will emerge in the energy sector. However, if a district heatingcompany want to initialize a blockchain project we advise the companies to start a pilot projectthat does not affect the current business model but has the potential to be scaled. Since theblockchain technology enhances collaboration, it is important to consider which partners shouldbe included and how the application can create value for all involved parties. However, due to theuncertainty of the technology, companies need to be well aware of that assumed created value maynot be reached as expected. Furthermore, district heating companies also need to bear in mindthat other parameters, for example additional technologies, policies or infrastructure systems, maybe necessary to implement in order to create value from a blockchain solution. Blockchain beskrivs ofta som något med ändlös teoretisk potential. I verkligheten är det dock svårtatt fastställa hur blockchain kan användas och vilka möjligheter blockchain kan skapa. Den osäkraframtiden för blockchain är en utmaning för många företag att förhålla sig till. Inte minst för storaetablerade företag då blockchain kan användas för att decentralisera en centraliseradmarknadsstruktur. Syftet med denna undersökande studie är att utvärdera blockchainapplikationerför ett fjärrvärmeföretag i Stockholm, för att förstå gynnsamma områden,nödvändiga kriterier vid genomförande och hur blockchain skulle kunna möjliggöra nyaaffärsmöjligheter på fjärrvärmemarknaden. För att uppfylla uppsatsens syfte genomfördes enlitteraturstudie och en empirisk studie. Inom litteraturstudien genomfördes en omfattandeundersökning av blockchain och fjärrvärme. Den empiriska studien bestod av 17 intervjuer, bådeinterna intervjuer med anställda från Stockholm Exergi och externa intervjuer med experter inomblockchain, fjärrvärme och energisektorn. Vidare genomfördes under slutfasen två workshops isamarbete med Stockholm Exergi, för att utvärdera och prioritera de skapade blockchainapplikationerna.Rapporten presenterar 32 blockchain-applikationer inom 10 olika områden inomfjärrvärmeindustrin. Applikationerna är kategoriserade efter sin potential i tre grupper, grön för deapplikationer som kan vara fördelaktiga för ett fjärrvärmeföretag och bör fortsätta undersökas,orange för de applikationer som sannolikt inte skulle vara fördelaktiga och röd för de applikationersom inte är intressanta för ett fjärrvärmeföretag att fortsätta undersöka. Vissa applikationerfokuserar på att lösa de ineffektiviteter som finns för fjärrvärme och vissa på att utnyttja fördelarnamed blockchain. Det åtta applikationer med grön prioritering presenteras mer detaljerat. Ettframtida scenario togs fram för att ta hänsyn till att blockchain sannolikt kommer att ha störrepåverkan i framtiden. Detta används som hjälpmedel när situationsanalysen för applikationernagenomförs. Dessutom utvecklades ett ramverk som har som syfte att vara ett verktyg för ettfjärrvärmeföretag att utnyttja när en blockchain implementering övervägs. Ramverket är inriktatpå fjärrvärmeföretag men kan även användas av andra aktörer.Vår rekommendation till ett fjärrvärmeföretag i Stockholm är att vänta ett eller två år, samtidigtsom de håller sig uppdaterade om marknadsförändringar för blockchain. Särskilt viktigt för ettfjärrvärmeföretag är att hålla sig uppdaterad om huruvida nya blockchain-standardiseringar uppstårinom energisektorn. Om ett fjärrvärmeföretag vill initiera ett blockchain-projekt, rekommenderarvi att starta med ett pilotprojekt som inte påverkar den nuvarande affärsmodellen, men harpotential att skalas. Eftersom blockchain-teknologin möjliggör samarbete är det viktigt attöverväga vilka partners som kan ingå i lösningen och hur applikationen kan skapa värde för allaberörda parter. Företag måste emellertid vara väl medvetna om att det förväntade värdet kanskeinte uppnås på grund av teknologins osäkerhet. Dessutom måste företagen också överväga attandra parametrar, till exempel andra teknologier, politik eller infrastruktur, är nödvändiga, för atten blockchain implementering ska skapa värde.

Using 1281 pedestrian tunnels scattered over Stockholm, Sweden’s capital, we investigate the nature and distribution of graffiti in three types of underpasses (pathways, cycleways, and stairways). Combining crowdsourced data and police records, we compare graffiti levels and geography using fieldwork inspections, regression models, and Geographic Information Systems (GIS). The findings indicate that graffiti recorded to the police is present in only a quarter of the pedestrian tunnels, suggesting that recorded practices are concentrated in specific underpasses. Graffiti is more commonly found in larger tunnels, particularly cycling underpasses. Proximity to metro stations, schools, and the presence of young males in the area are factors linked to graffiti occurrence, although not consistently. These results highlight the complexities of relying on graffiti records for public space management, particularly the challenges professionals face in aligning the maintenance of pedestrian tunnels with urban sustainability goals. QC 20250317

I denna studie har vi undersökt olika bostadsföretags uthyrningspolicy inom Stockholmsområdet samt hur pass lättillgänglig information är om bostadssökningsprocessen via deras hemsidor. Vi vill undersöka om det finns någon skillnad mellan hur bostadsföretag förmedlar sina grundkrav och på vilken nivå dessa ligger för en bostadssökande. Hur påverkar detta samhället och i synnerhet hur påverkar det oss som studenter? Finns det även en skillnad mellan kommunala och privata bostadsföretag i Stockholmsområdet?För att finna svar på frågeställningarna undersökte vi 13 olika privata- och kommunala bostadsföretag; HSB, Ikano Bostad, Wallenstam, Byggvesta, Rikshem, Willhem, HEBA Fastigheter AB, Svenska Bostäder, Stockholmshem, Familjebostäder, Micasa Fastigheter, Stadsholmen samt Stockholms Studentbostäder. Vi studerade hur företagens respektive uthyrningspolicy var utformade på deras hemsidor samt hur lättillgängligt det var att hitta viss väsentlig information som bostadssökande. Detta blev en jämförelse företagen sinsemellan vilket gav oss en överskådlig bild på vad som bör förbättras inom området.Det visade sig finnas en betydlig skillnad mellan privata- och kommunala bostadsföretag där den största skillnaden var att privata bostadsföretag reglerar sina uthyrningspolicy hårdare än vad de kommunala gör. Alla hemsidor var mer eller mindre dåligt utformade gällande tillgänglighet och språkmöjligheter. Vi behandlade även våra studiefrågor utifrån ett hållbarhetsperspektiv då det anses vara betydande för ett fortsatt fungerande samhälle.Avslutningsvis gavs rekommendationer för bostadsföretagen för att förbättra sina hemsidor och policys. Störst vikt bör läggas på att förbättra möjligheten för alla individer på bostadsmarknaden för att få en bostad. Samt att förbättra bostadsföretagens hemsidor i fråga om transparens och språkmöjligheter, för att utveckla bostadsmarknaden ur ett socialt och teknologiskt perspektiv. The main focus in this thesis has been to examine different housing companies rental policy in Stockholm and to review how easily it is to maintain relevant information regarding the leasing process through the companies websites. We want to see if there is any difference between how the housing companies convey their demands and how this affects the person looking for a rental apartment. Furthermore, we want to see how everything above affect the society, especially students. Is there any difference between municipal housing companies and private housing companies in Stockholm?We analysed 13 websites belonging to different housing companies to find answers to our questions. The housing companies involved in the study are: HSB, Ikano Bostad, Wallenstam, Byggvesta, Rikshem, Willhem, HEBA Fastigheter AB, Svenska Bostäder, Stockholmshem, Familjebostäder, Micasa Fastigheter, Stadsholmen and Stockholms Studentbostäder. We studied how the different companies have decided to form their respective rental policy and how easy it is to find relevant information as an applicant. A comparison between the companies became possible with the gained information, the comparison gave us a clear picture of some recommended improvements within the field.It turned out to be a significant difference between the municipal rental companies and the private rental companies, where the private rental companies control their rental policies more strictly than the municipal rental companies. All of the housing companies’ websites were more or less weak in terms of availability and language possibilities. In the study we also covered the perspective of sustainability consider its significance for a further functioning society.In conclusion we provided recommendations for the housing companies in order to improve their rental policies and their websites. In our opinion should most effort be put on improving the opportunities for all individuals on the housing market to receive a residence. The housing companies’ websites should be improved with regard to transparency and language possibilities, to develop the housing market from a social and technologic perspective.

To avoid damages and costs for the society due to flooding is it important to be able to model accurate rain scenarios. Due to climate change is it thought that there will be more heavy rainfalls in the future which will increase the risk for flooding. This master thesis will therefore look at the parameters that affect the risk for flooding with focus on raincloud movement and peak arrivals. Earlier research has shown that different directions of the rain will affect the flooding risk differently. Generally will a rain that has the same direction as the downstream flow lead to a higher risk for flooding. The peak arrival time has also shown to lead to different results were a late peak arrival seems to lead to a higher risk for flooding. There is usually too little time and costly to test different movement and peak arrival scenarios, so this report will focus on which of these parameters that have the greatest flooding impact and largest internal variation. MIKE 21 (created by DHI) is the software used to model the different rain scenarios. The rain types used to test the different scenarios will be a uniform rain, a traditional CDS-rain and five rain shapes that are based on empirical rain types created by SMHI. The shape of the empirical rains is based on several studies from measured rain events with weather radar. Weather radar have become a fundamental tool in weather forecasting because it can collect data in near real time and also measure the spatial variation inside the rainfall. These seven mentioned rain types will not be moving, and the rain will have the same spatial intensity over the study area. They will be compared both to each other but also to a CDS-rain that will move over the study area in 4 different directions (north-south, east-west, south - north and west - east). The different directions gave all very similar results while there was a larger difference between the rain types with different peak arrivals. The peak-value seems to be an important factor when it comes to flooding risk based on the results in this report. The constant uniform rain had the lowest amount of flooded areas while the CDS-rain (which had the highest peak) affected the area the most.

The solid oxide fuel cell (SOFC) is a potential high efficient electrochemical device for vehicles, auxiliary power units and large-scale stationary power plants combined heat and power application. The main challenges of this technology for market acceptance are associated with cost and lifetime due to the high temperature (700-1000 oC) operation and complex cell structure, i.e. the conventional membrane electrode assemblies. Therefore, it has become a top R&D goal to develop SOFCs for lower temperatures, preferably below 600 oC. To address those above problems, within the framework of this thesis, two kinds of innovative approaches are adopted. One is developing functional composite materials with desirable electrical properties at the reduced temperature, which results of the research on ceria-based composite based low temperature ceramic fuel cell (LTCFC). The other one is discovering novel energy conversion technology - Single-component/ electrolyte-free fuel cell (EFFC), in which the electrolyte layer of conventional SOFC is physically removed while this device still exhibits the fuel cell function. Thus, the focus of this thesis is then put on the characterization of materials physical and electrochemical properties for those advanced energy conversion applications. The major scientific content and contribution to this challenging field are divided into four aspects except the Introduction, Experiments and Conclusions parts. They are: Continuous developments and optimizations of advanced electrolyte materials, ceria-carbonate composite, for LTCFC. An electrolysis study has been carried out on ceria-carbonate composite based LTCFC with cheap Ni-based electrodes. Both oxygen ion and proton conductance in electrolysis mode are observed. High current outputs have been achieved at the given electrolysis voltage below 600 oC. This study also provides alternative manner for high efficient hydrogen production. Compatible and high active electrode development for ceria-carbonate composite electrolyte based LTCFC. A symmetrical fuel cell configuration is intentionally employed. The electro-catalytic activities of novel symmetrical transition metal oxide composite electrode toward hydrogen oxidation reaction and oxygen reduction reaction have been experimentally investigated. In addition, the origin of high activity of transition metal oxide composite electrode is studied, which is believed to relate to the hydration effect of the composite oxide. A novel all-nanocomposite fuel cell (ANFC) concept proposal and feasibility demonstration. The ANFC is successfully constructed by Ni/Fe-SDC anode, SDC-carbonate electrolyte and lithiated NiO/ZnO cathode at an extremely low in-situ sintering temperature, 600 oC. The ANFC manifests excellent fuel cell performance (over 550 mWcm-2 at 600 oC) and a good short-term operation as well as thermo-cycling stability. All results demonstrated its feasibility and potential for energy conversion. Fundamental study results on breakthrough research Single-Component/Electrolyte-Free Fuel Cell (EFFC) based on above nanocomposite materials (ion and semi-conductive composite) research activities. This is also the key innovation point of this thesis. Compared with classic three-layer fuel cells, EFFC with an electrolyte layer shows a much simpler but more efficient way for energy conversion. The physical-electrical properties of composite, the effects of cell configuration and parameters on cell performance, materials composition and cell fabrication process optimization, micro electrochemical reaction process and possible working principle were systematically investigated and discussed. Besides, the EFFC, joining solar cell and fuel cell working principle, is suggested to provide a research platform for integrating multi-energy-related device and technology application, such as fuel cell, electrolysis, solar cell and micro-reactor etc. This thesis provides a new methodology for materials and system innovation for the fuel cell community, which is expected to accelerate the wide implementation of this high efficient and green fuel cell technology and open new horizons for other related research fields. QC 20131122

In a development area of Trollbäcken, a suburb half an hour south of central Stockholm, I have created a sustainable housing project in the form of a byggemenskap/baugemeinschaften with a focus on sustainability. With the help of friends and family members and their wishes for a future home as basis for my programme, I investigated what sustainable housing could be with a special interest in the relationship between material and immaterial sustainability, between the buildings and the community that inhabits and maintains them, aiming to create a built environment that supports the sustainable lifestyles of the residents.

A common goal among governments is to promote socio-economic development and raise living standards of populations worldwide. As of today, some countries have achieved considerable development levels as measured by the Human Development Index (HDI). On the other hand, a large part of the world population lives in developing countries, and many still lack access to the services and goods thought to be standard in the modern society. This discussion paper engages in a critical discussion of the Kuznets Environmental Curve concept which implies a emporary increase in carbon emissions per unit of GDP as countries transition to higher development levels. The coming years will see enduring efforts for socio-economic improvements in low and mid-developed countries, but the feasibility of conventional development models is put into question. Development paths based on emission-intensive growth have to be phased-out towards a low-carbon equivalent, not only by the leading countries but most importantly in the developing world. Qc 20120217

Air conditioning, refrigeration and heat pumps use around 20%of theglobal electricity and it is estimated 25% of this is wasted due to poor commissioning, optimization, and maintenance. To minimize these problems and wastedenergy, predictive maintenance is a vital key to solve this issue. Due to the nature of thermal systems, its operation conditions are goingtovarysignificantly during different seasons for their components, thus comparingabaseline within models can be a subjective task if done through traditional COPmeasuring methods. Utilizing machine learning methods such as Multi-Layer Perceptrons andPCAanalysis, paired with ClimaCheck‘s internal method with the measurements of HVACsystems can help stablish these required baselines, and it can providespecificmeasurements of the efficiency expected of each component within theloop, providing warnings for decreases in performance caused by poor installationordegraded components. The method used led to highly reliable and fast results to determine virtual modelsfor the internal efficiencies of both condensers and evaporators with a lowRMSEof0.12% and coefficients R2 and D2 above 90% of correspondence with anaveragerunning time of 3 seconds for every hour of data. The performance does extendtoother values like the general internal efficiency (SEI) but does not extendwiththesame performance to KPIs based on temperature. Luftkonditionering, kylning och värmepumpar förbrukar cirka 20 % av den globalaelenergin, och det uppskattas att 25 % av denna energi går till spillo på grundavdåligdriftsättning, optimering och underhåll. För att minimera dessa problemochslöseri med energi är förebyggande underhåll en viktig nyckel för att lösa problemet. På grund av de termiska systemens natur kommer driftförhållandena att varieraavsevärt under olika årstider för deras komponenter, vilket innebär att det kanvaraensubjektiv uppgift att jämföra en baslinje inom modeller om det görs med traditionellaCOP-mätmetoder. Användning av maskininlärningsmetoder som Multi-Layer Perceptrons och PCA- analys, i kombination med ClimaChecks interna metod med mätningar av HVAC- system, kan hjälpa till att fastställa dessa nödvändiga baslinjer, och det kangespecifika mätningar av den effektivitet som förväntas av varje komponent i slingan, vilket ger varningar för minskad prestanda orsakad av dålig installation eller försämrade komponenter. Den metod som användes ledde till mycket tillförlitliga och snabba resultat för att fastställa virtuella modeller för den interna effektiviteten hos både kondensorer ochförångare med ett lågt RMSE på 0,12% och koefficienter R2 och D2 över 90%avöverensstämmelsen med en genomsnittlig körtid på 3 sekunder för varje timmemeddata. Prestandan sträcker sig till andra värden som den allmänna interna effektiviteten (SEI) men sträcker sig inte med samma prestanda till KPI: er baseradepå temperatur.

The majority of low income households in South Africa have limited access to electricity, and typically cook on stoves fuelled by paraffin. Paraffin represents a fossil fuel. It is a relatively cheap fuel in South Africa. Another fuel that can also be used for cooking is wood pellets, which is a renewable fuel. It can be used in a similar way to that of paraffin and is relatively cheap compared to other renewable energy sources. To investigate if living conditions among low income households can be improved the focus of the study was to evaluate the sustainability of cooking on paraffin and wood pellets. This was done by comparing social, environmental and economic aspects associated with the two cooking fuels. The social aspects were investigated through an interview study, the environmental aspect through a comparative life cycle assessment (LCA) and the economic aspects through a partial life cycle cost analysis (LCCA) focusing on the user phase. The interview study showed that paraffin users considered four aspects as the most important when cooking, namely safety, health, affordability and quality. The study also found that the majority were willing to change to another cooking fuel if these aspects were fulfilled. The LCA showed that both systems score the highest on 9 out of 18 environmental impact categories over a 16-year perspective. The economic analysis showed that the user phase of the wood pellet system is more economically beneficial during the 16-year time period than the paraffin system. It was concluded that wood pellets could be used as an option to paraffin for cooking and would most likely increase living conditions for low income households. Majoriteten av låginkomsthushåll i Sydafrika har begränsad tillgång till elektricitet och vanligtvis sker matlagningen på paraffinspisar. Paraffin är ett fossilt bränsle. Det är ett relativt billigt bränsle i Sydafrika. Ett annat bränsle som också kan användas för matlagning är träpellets som är ett förnyelsebart bränsle. Det kan användas på liknande sätt som för paraffin och är ganska billigt i jämförelse med andra förnybara energikällor. För att undersöka om levnadsförhållanden för låginkomsthushåll kan förbättras låg fokus för denna studie på att utvärdera hållbarheten för att laga mat på paraffin och träpellets. Detta genomfördes genom att jämföra sociala, ekologiska och ekonomiska aspekter associerade med dessa bränslen för matlagning. De sociala aspekterna undersöktes genom en intervjustudie, de miljömässiga aspekterna genom en jämförande livscykelanalys (LCA) och de ekonomiska aspekterna gjordes genom en livscykelkostnadsanalys (LCCA) för användarfasen. Intervjustudien visade att paraffinanvändare anser att fyra aspekter är de viktigaste vid matlagning, nämligen säkerhet, hälsa, kostnad och kvalitet. Studien visade också att majoriteten var villiga att byta till ett annat bränsle för matlagning om dessa aspekter var uppfyllda. Livscykelanalysen visade att båda systemen hade högst miljöpåverkan i 9 av 18 miljöpåverkanskategorier vardera inom ett 16-årsperspektiv. Den ekonomiska analysen visade att under en 16-årsperiod var användarfasen mer kostnadseffektiv för matlagning på träpellets jämfört med paraffin. Studien visade att träpellets kan användas som ett alternativ för paraffin vid matlagning och kommer troligtvis öka levnadsförhållanden för låginkomsthushåll.

Modern energy poverty in sub-Saharan Africa is one of the primary challenges that humanity faces today. Rural electrification in this region is a complex issue that needs to be well understood by developed and developing countries in order to thrive on this situation. Further, due to the significant amount of installed capacity that this market will represent in the coming decades, the impact of this market in climate change could be irreversible. There is, therefore, a need of well addressing this market in order to mitigate and minimize its impact in climate change. This work first presents and studies the rural electrification market in sub- Saharan Africa and second, focuses in Mini-grids, one of the most successful alternatives to grid extension in the last decade. By analyzing the different aspects that a Mini-grid involves and reviewing several case studies worldwide, this thesis tries to identify what are the challenges and opportunities that Mini-grids face to become successful in sub-Saharan Africa, particularly in East Africa where the author has carried a 6-month internship hosted by the company African Solar Designs Ltd (Nairobi, Kenya). Innovative Business models, Policy and Inclusive Business are identified as key aspects of Mini-grids as failures in the experiences in sub-Saharan Africa. The A-B-C Telecom Mini-grid approach (A: Anchor, B: Business; C: Community) is presented here as a commercially viable solution for Mini-grids in rural areas of East Africa, where there is a need of access to modern energy as well as many off-grid Base Telecom Stations that need more affordable electricity. The A-B-C Telecom Mini-grid model is first defined, secondly the technology is simulated and optimized using Homer software; a PV-diesel hybrid Mini-grid is selected the best option for this market. Then the business model for the A-B-C concept is defined and is financially simulated under certain parameters shown. A financial sensitivity analysis is also implemented to understand how viable is the model presented and how sensible to certain financial parameters is. To finish with, this project identifies the model limitations and the major barriers that this model face to succeed; favorable regulatory environment, finance to scale up the concept and donor agencies and rural energy practitioners to understand and switch their approach of rural electrification projects into a more sustainable and commercially viable one.