På flera ställen i norden, bland annat i Trelleborg kommun i södra Sverige har man försökt skapa hållbara kretsloppsprojekt som syftar till att frigöra badstränder från uppspolade illaluktande alger genom att samla in dem för att producera biogas. Därefter vill man återcirkulera näringsämnen från hav till land genom att avsätta rötresten på jordbruksmark som biogödsel. Tyvärr riskerar då halterna av kadmium i algerna att utgöra ett hot mot en trygg livsmedelsproduktion då kadmiumnivåerna i den jordbruksmark som är ämnad att bli gödslad, i många fall kommer att ackumuleras upptill oacceptabla nivåer. Tidigare har reduktionsförsök av kadmiumnivåer i alger gjorts innan rötning genom extraktion med syra. I denna studie prövades om vanligt sötvatten kunde användas som extraktionslösning. Dessutom prövades om kalciumhydroxid kunde reducera kadmiuminnehållet antingen genom jonbyte mellan kadmium och kalcium eller genom extraktion i egenskap av bas. Ingen av dessa metoder visade sig reducera innehållet kadmium med mer än 10 %. Extraktion med myrsyra användes som referensmetod och reducerade innehållet med 60 % vilket är vad tidigare studier visat. På grund av mätosäkerhet bör inte resultaten tolkas för exakt. Därefter undersöktes om metanpotentialen i algerna påverkades av behandlingarna. Tyvärr stötte utrötningsexperimentet på problem vilket gör resultaten högst osäkra. Ingen behandlingsmetod verkade dock ge en negativ påverkan på metanpotentialen. Myrsyrametoden verkar snarare öka metanutbytet genom att algerna kan ha förhydroliserats. Slutligen tog studien ett större perspektiv kring kadmiumflöden i samhälle och natur samt lyfte blicken mot andra tekniker som har potential att göra näringsåterföring från alg till jordbruksmark möjlig. Vikten av förståelse för massbalansen av kadmium i det aktuella området understryks. Tekniker för utvinning av näringsämnen ifrån en rejektvätska och ifrån aska från rötresten kan göra det möjligt att samröta alger med annat lämpligt substrat för att sedan ta ut näringsämnen som fosfor ur rötresten, rent från föroreningar. / Beach cast algae that accumulates and creates thick layers of degrading biomass makes beaches almost inaccessible for tourists with its consistence and bad odor. In several places in Scandinavia there is an interest to clean the beaches from smelly algae and at the same time exploit the potential of the algae as a source of plant nutrients and also of energy. The municipality of Trelleborg in the south of Sweden has been trying to find a sustainable way to use the algae as substrate for production of biogas and then dispose the digested residuals onto farmland. However, the relatively high cadmium content in the algae threaten to make cadmium levels in agricultural soil to accumulate over time and thus putting food production at risk. Techniques involving acid solutions have earlier been proven to reduce the cadmium content with up to 77 % from algae through extraction. In full scale this would demand great volumes of acid and thus would not be likely to be cost effective, considering the relatively low bio methane potential (BMP) around 94 – 290 Nml CH4/g VS and low content of nutrients (e.g. 2,4 – 3,4 g P/kg TS) in algae.   The purpose of this study was to find a potentially more cost effective process to reduce cadmium content in algae by trying extraction of cadmium from algae with A) fresh water and B) a base of sodium hydroxide at pH 11. Formic acid has been used in earlier studies and got to serve as a reference method in this study. The algae from a beach on the southernmost tip of Sweden, was mixed with freshwater and for the other two methods, freshwater and acid or base. After 24 hours, the fluid was extracted from the mix and the dry substrate and the fluid, as well as untreated algae was analyzed for the concentration of cadmium. Results showed that the harvested algae had a concentration of 2 mg Cd/ kg DW which is similar to earlier analyzes. What was also shown was that neither the fresh water nor the sodium hydroxide managed to extract more than approximately 10 % of the total content. The Formic acid did extract approximately 60 % of the total content which is comparable to results of earlier studies. All results are however coupled with great uncertainties of ±20 – 44 %.   Furthermore the aim was to examine whether the extraction experiments had any effect on the bio methane potential of the algae. So, both treated and untreated substrate was mixed with inoculum and put into anaerobic digestion in 37 °C for 44 days in total together with a blank and a control with sodium acetate. Unfortunately the BMP test had suffered problems resulting in great uncertainties that make any interpretation almost pointless. Still, the extraction experiments did not seem to have a negative effect on the BMP (≈ 80 ml CH4/g VS) when comparing with the BMP results from the non-treated substrate. The treatment with formic acid showed to improve the BMP (≈ 140 ml CH4/g VS) but some of that methane came from the acid itself. But it is recommended to see these results only as vague indications, if anything.   Additionally a final aim was to take a broader scope and discuss further solutions on how to proceed with the concept of algae-biogas-nutrient recovery. In order to do this the background part of this work was extended with additional literature studies of the natural and anthropogenic sources and flows of cadmium in the biosphere, earlier experiments with algae to biogas/bio fertilizer and finally other techniques for removal of cadmium from different substrate. The basis for this was the Skåne region and the algae to biogas projects that have been running in the municipality of Trelleborg, even if the discussion reaches out over the society as a whole as well.   It became clear that before any algae are disposed it is of great importance to have a good, holistic picture of the mass balance of cadmium in the area that has been assigned to receive the residuals from digested algae. Important factors are natural content of cadmium in the soils and the loads of atmospheric deposition of cadmium in the area. Algae are not fit to serve as the single substrate in a biogas process so co-digestion of algae and other substrate is desired to achieve the right conditions and to optimize BMP. It will also dilute the cadmium rich algae and help the Cd/P ratio and thereby reducing the load of cadmium on to farmland.   In the experiments of this study as well as in earlier studies, the approach has been to place the cadmium reduction step before digestion because a co-digestion would dilute the cadmium, thus making any extraction much more ineffective. But if the algae are to be co-digested with a substrate with a similar profile of contamination, it would be logical to instead put the cadmium reduction step after the digestion. This could potentially enhance the reduction since the algae cell structure has been degraded and hopefully are more likely to release cadmium through extraction. A different approach, still after co-digestion, is to consider technologies where phosphor and nitrogen can be extracted from a fluid reject of the residuals or from the ashes of combusted residuals. This would allow the co-digestion of substrate with completely different profiles of contamination, like algae and sewage sludge, since uncontaminated nutrients can be extracted in form similar to commercial fertilizers. These alternative ideas would be interesting as an approach for further studies.

The construction industry is responsible for about one third of the annual global GHG emissions and its products carry significant lock-in risks: infrastructure and structures built today will contribute to anthropogenic GHG emissions for the next decades. Due to operational diversity, structural complexity, and the emission fluctuations associated with project-based work, construction companies struggle, however, with defining relevant carbon reduction targets. This study aimed at deriving a conceptual model for how these organizations can set targets that are meaningful in respect to their business characteristics. Conducted as a case study of the Skanska group, a qualitative approach was used: Interviews with different business units as well as literature reviews about the existing target setting methodologies, science-based methods, and approaches in other yet similar industries as well as competitors were leveraged to collect information. This data was qualitatively analyzed, discussed and compared against the requirements of defining reduction targets in the construction industry. An overarching, company-wide target is neither practically conceivable nor environmentally robust. Companies such as the Skanska group are recommended to differentiate between their different operations and to develop separate targets for each. Depending on the business volatility of these operations absolute or relative target setting methods are to be used. Meaningful relative targets require operations with low emission homogeneity to be broken down into further separate targets for individual activities, e.g., individual targets for the manufacturing of asphalt and concrete. Construction work itself has to be addressed by individual targets on project level for each project type, e.g., highways, bridges, offices, and residential, in order to avoid the issues of structural complexity and emission fluctuations. Creating a company-wide performance indicator embracing all construction work is only possible by normalizing these project-based targets a second time, e.g., by measuring the turnover of projects meeting the individual reduction targets.

This report covers the social sustainability agenda in the suburbs Rosengård and Kroksbäck, situated in Malmö. These suburbs where constructed mainly in the years 1960-1975 and are now in need of refurbishing. There is also a housing shortage in Malmö and the demand is mainly for inexpensive apartments. Young adults, students, immigrants, senior citizens and families alike are looking for places where they can afford to live. The high demand for living space and the need of renovation could spark a gentrification process which would not be socially sustainable. The main actors whose social sustainability agendas are reviewed are the municipality of Malmö and the municipal owned housing company of MKB as well as the tenants’ association. The report also covers how the dialogue between the residents in Rosengård, the civil servants of the city and the landlords is carried out. Reactions from the residents in Rosengård have been researched in newspapers, but it proved hard to find while criminal reports where abundant. Lastly two examples on how the social sustainability agenda have been carried out in Gothenburg is presented. The methodology which the results are based on is a literature review. The report finds that both Malmö and Gothenburg are using a matrix formed decision tool in order to incorporate social aspects in all planning decisions. This is something which works well in both cities. The municipality of Malmö took a decision in 2014 that the social justice will increase when building new apartments. They do however realize the most of the newly constructed homes might be too expensive but they hope that this will eventually free up cheaper apartments. Different investment programs have been initiated in Rosengård, Rosengård I förvandling is one of them. Part of this program was based on local farming and different pedagogical activities. MKB are using social clauses when hiring different contractors, they stipulate that ten percent of the workforce should be locals or people who previously have been unemployed. This would be one the few tangible solutions which MKB is contributing with to solving the problem with lack of social sustainability. The tenants’ association is mainly focusing on minimizing the rent increase. They do however see a potential in so called neighborhood effects such as social learning were tenants are affecting other tenants in a positive way. The tennants’ association believes, as do the municipality of Malmö, that this can be achieved partly by constructing new houses among the older ones. The dialogue between the residents and the municipality used to be characterized as too little too late in the planning process. The revised aim with the dialogue is now to bring the citizens opinions into the decision process at an earlier stage. A potential problem could be the language barriers as there are many immigrants living in suburban Malmö. However in projects where the dialogue where given a priority the outcome became a success and the decision enjoys a broad support. As a recommendation for future research, a survey or deep interviews with the residents on their thoughts about actions taken to increase the social sustainability could be carried out. This is something which this report is lacking, good feedback from the residents. / Den här rapporten behandlar olika aktörers bidrag till den sociala hållbarheten i Malmös förorter. Dessa förorter byggdes mellan åren 1960-1975 och är nu i stort behov av upprustning. Samtidigt lider Malmö av en stor bostadsbrist och det är främst bostäder med låga hyror som efterfrågas. Ungdomar, studenter, invandrare, pensionärer och familjer letar efter bostäder som de har råd med. Stor efterfrågan på bostäder och ett stort renoveringsbehov kan innebära en gentrifiering som inte är socialt hållbar. De aktörer vilkas sociala hållbarhetsarbete har undersökts är Malmö stad, det kommunala bostadsbolaget MKB samt hyresgästföreningen. Dessa är organisationer som har en stor möjlighet att påverka agendan runt den sociala hållbarheten i Malmös förorter. Vidare undersöker rapporten också på hur arbetet med medborgardialog ser ut samt vilka reaktioner olika satsningar fått från de boende. Slutligen så redovisas två erfarenheter från Göteborgs miljonprogramsområden. Rapporten baseras på en litteraturstudie. Undersökningen visar att både Malmö och Göteborg jobbar med en form av matrissystem för att säkerställa att den sociala hållbarheten inkluderas i planfrågor och har visat sig fungera bra i båda städerna. Malmö kommun tog 2014 ett beslut om att social rättvisa ska vara vägledande vid nybyggnation av flerfamiljshus. Det finns en insikt i att många nybyggda lägenheter kan bli dyra men förhoppningen är att detta ska frigöra billigare bostäder. Olika investeringsprogram har sjösatts i Rosengård där Rosengård i förvandling är ett exempel. Delar av detta program fokuserar på olika pedagogiska aktiviteter och stadsodling och en bieffekt har blivit att människor har fått en mer positiv syn på Rosengård. MKB fokuserar sitt sociala hållbarhetsarbete på sociala klausuler för underleverantörer där målet är att tio procent av arbetarna ska vara bosatta i området eller tidigare arbetslösa. Hyresgästföreningens fokus ligger på att hålla hyreshöjningarna på en så låg nivå som möjligt men de ser också en potential med såkallade grannskapseffekter, där boende påverkar andra boende på ett positivt sätt. Hyresgästföreningen och Malmö stad tror att detta är något som delvis kan uppnås genom att bygga nya flerbostadshus bland äldre bebyggelse. Medborgardialogen har tidigare karakteriserats av att den varit fokuserad på att informera de boende om olika beslut. Det nya målet med medborgardialogen är att det ska föra in de boendes åsikter som en aktiv del i beslutsprocessen i ett tidigt stadium. Ett potentiellt problem är de språkbarriärer som kan uppstå i ett så multikulturellt samhälle som Malmö. Erfarenheter visar dock på goda resultat i projekt där medborgardialogen prioriterats. Det visade sig problematiskt att finna reaktioner från de boende som är kopplade till de olika initiativen som syftar öka den sociala hållbarheten. Genomförandet av en sådan studie med hjälp av enkäter eller djupintervjuer är ett förslag för att nå ökad kunskap och ett förslag på fortsatt forskning inom området.

The growing interest around offshore wind power, providing at the same time better wind conditions and fewer visual or environmental impacts, has lead many energy suppliers to consider the installation of offshore wind farms. However, the marine environment makes the installation and maintenance of wind turbines much more complicated, raising the capital and operation costs to an undesirable level and preventing the fast progression of this technology worldwide. Availability of offshore wind turbines varies between 65 and 90% depending on location, whereas onshore turbines range between 95 and 98% in most cases. In 2009, the ETI launched a research project aiming to improve economical efficiency of offshore wind farms by increasing their availability and decreasing their maintenance costs (partly through replacing corrective maintenance by preventive maintenance). This project named “Inflow” involves the development of a condition monitoring system, a system designed to monitor the state of different wind turbine components, and to analyze this data in order to determine the wind turbines overall condition at any given time, as well as its potential system ailments   This paper describes two different approaches to perform the condition monitoring of offshore wind farms, the first one involves thresholds-based analysis, while the other involves pattern recognition.

Sudden change on earth’s climate, which is a result of an increase in CO2 in the atmosphere, is mainlycaused by burning of fossil fuels for various energy services. However, for the energy services to befavourable to the environment, there should be a balance with the environmental protection, and we cancall that “Sustainable Innovative Development”. “EXPLORE Polygeneration” initiative will serve as an important tool to promote the application ofrenewable technologies extending to the future sustainable energy engineering field. This paper is intendedin investigating a suitable fuel supply for the microturbine based micro CHP system available at theDivision of Heat and Power Technology, KTH, Sweden; for a site called “Alema Farm PLC”, Bishoftu,Ethiopia. Though there is a large biomass energy resource and a huge potential to produce hydroelectric power inEthiopia, the modern energy sector is very small and the energy system is mainly characterized by biomassfuel supplies and household energy consumption. The nation’s limited biomass energy resource is believedto have been depleting at an increasingly faster rate. Of the many and surplus amount of renewable energy resources available in and around Alema FarmPLC, poultry litter and pig’s manure are selected to be the two main energy sources for the CHP systemavailable in the lab, after passing through different conversion techniques. However, after consideringsome basic properties like: Energy content and Bulk Density of the fuel, Moisture content , Ashcharacteristic, Tar content, Fuel logistics, Local storage, Fuel feeder system, and Magnitude of GHGReduction; poultry litter is found to be the most convenient to produce a syngas with a Downdraftatmospheric gasifier available in the HPT lab. Finally, For the problems caused by the nature of the poultry litter by itself and the methods used in theconversion process, the 40 TRIZ principles of TRIZ inventive principles is used and some major pointsare recommended.

Geographic information systems (GIS) are increasingly being used in energy planning and by private sector practitioners. Through qualitative interviews with 49 leading practitioners in the public and private sector, this thesis establishes the data of most importance, current open access data sources for energy access along with the information currently lacking from open data sources. The interviews revealed grid infrastructure, population density, renewable power potential and energy expenditure to be the most sought after data for both practitioners’ groups. However, it was evident that the private sector had a stronger focus on land, water resource and climate data determining the renewable power potential for a specific area of interest, while the public sector focused on socioeconomic indicators and energy expenditure. A following data aggregation and analysis of the most desired datasets showed that a majority of the needed datasets were available with the exception of energy expenditure. A least-cost option electrification model developed by KTH-dESA has proven to be a powerful tool in assessing the cost of nationwide electrification. This thesis compares the average least-cost option electrification cost for each region in Tanzania with a projected average income. The comparison showed that the average household cost for least-cost option electrification as a share of projected household income varies between regions. The average share per household in the western regions of Tanzania were significantly higher compared to households in the central and eastern regions. The comparison was combined with the geographical location of donor-supported energy development projects showing that majority of the projects were located in the central parts of Tanzania and not targeting the most vulnerable households in regions furthest away from the national grid. In order to successfully introduce electricity nationwide in Tanzania, more support needs to be provided to the poorest regions.  Open data aggregation and coordination are the key to expand the support from GIS for energy access. Even though multiple data sources have been identified, they are scattered and leads to data being collected again. Coordinated efforts aimed to provide means to share aggregated updated and freely accessible data can help reduce high transaction costs, helping to alleviate energy poverty. / Geografiska informationssystem (GIS) används i allt större utsträckning inom energiplanering och av privata aktörer. Genom kvalitativa intervjuer med 49 ledande aktörer i offentlig och privat sektor redogör denna rapport för de viktigaste dataseten för aktörer, befintliga källor för öppen data och vilka informationsluckor som finns i dessa källor. Intervjuerna visade att dataseten gällande energiinfrastruktur, befolkningstäthet, potential för förnybar energi och energiutgifter var viktigast för både offentlig och privat sektor. Privat sektor hade ett större fokus på land, vatten och klimatdata, som alla är viktiga för att avgöra ett områdes potential för förnybar energi. Offentlig sektor hade ett större intresse av socioekonomiska faktorer och energiutgifter. En dataaggregation och analys visade att de mest eftertraktade dataseten fanns öppet tillgängliga med undantag för energiutgifter. En modell för energialternativ till lägsta kostnad utvecklad av KTH-dESA har visat sig vara ett kraftfullt verktyg för att kostnadsbedöma en landsomfattande elektrifiering. I en fallstudie för Tanzania jämför denna rapport den genomsnittliga kostnaden för hushåll för en implementering av en sådan elektrifiering med en beräknad genomsnittlig hushållsinkomst. Jämförelsen visade att kostnaden för hushållen som andel av total hushållsinkomst varierar kraftigt mellan regioner. Den genomsnittliga andelen av hushållsinkomsten som skulle läggas på elektricitet i de västra regionerna av Tanzania var betydligt högre jämfört med de centrala och östra regionerna. Jämförelsen kombinerade även detta resultat med den geografiska positionen hos biståndsstödda energiprojekt. vilken visade att majoriteten av dessa projekt fanns i de centrala delarna av landet och inte i de mest utsatta regionerna som präglas av låg genomsnittlig inkomst och långa avstånd till det nationella kraftnätet. För att framgångsrikt kunna genomföra en landsomfattande elektrifiering behöver mer stöd ges till dessa regioner. Aggregation av öppen data och koordinering är nyckeln till att framgångsrikt utveckla GIS som stöd vid framtida energiprojekt som syftar till att ge fler tillgång till elektricitet. Trots att flertalet datakällor kunde identifieras är dessa spridda vilket leder till att data behöver samlas in gång på gång. Koordinerade insatser för att öka möjligheten till att dela redan insamlad öppen och uppdaterad data kan bidra till att minska transaktionskostnader och därmed minska energifattigdomen

One of the biggest challenges of a residential building, when it is designed, is to be energy efficient and to provide simultaneously many hours of thermal comfort throughout the year. So, this was the scope of this thesis: to perform a parametric analysis of thermal comfort and energy efficiency in a house that was designed for the climate of Gotland in Sweden. After that, modifications were introduced to the base model and each scenario was checked for the geographical locations of Thessaloniki, Greece and Barcelona, Spain, in order to decide what option is better. The modifications to the base model were changes in the structure of the external wall (insulation materials and total width), the insulation of the internal wall, the thermal bridges (set to good), the windows (3-pane glazing, schedule opening, external window shading, integrated shading), the installation of HVAC system, photovoltaics with efficiencies 15%, 17% and 22% and the introduction of chimney. Based on the results, the Gotland scenario that included the base model plus the modifications of the external and internal wall, HVAC system, PVs with 22% and external window shading increased the energy use by 18.7% but improved the thermal comfort as the yearly hours of dissatisfaction reduced to 22 from 882, compared to the base model. Similar results were taken from the case with the integrated shading in which the energy increased to 19.3%, but the hours of dissatisfaction declined to 24 throughout the year. Regarding only the energy cost of the house, the best location is Barcelona (without cooling). Nevertheless, when considering the overall thermal comfort, the best place for the house is Gotland, as the building was designed for the cold environment of Sweden and not the hot weather of the other southern cities.

As demand for renewable energy sources increases so does the pressure exerted on the transmission grid. Variable sources strain the existing power lines and the control system needs to incorporate faster response times when redirecting power flow. Using HVDC grid technology multiple AC networks can be concatenated across longer distances. This creates op- portunity for solar- or wind power plants to be constructed further away from consumers. However this technology calls for a SCADA system being developed to bridge the gap between fast changing voltages throughout an HVDC grid and less frequent control rate of the underlying AC networks. This paper suggest an architecture where a centralised control system receives data from substation measurement units localised throughout the grid. A database and a GUI, created in Microsoft SQL Server and Zenon respectively, are developed in order to store, process and display the communicated information, such as voltages, currents and power flows. The control center would work on an update frequency of about one second up to a minute, thus being able to implement directions given by the AC grid control systems on the faster changing HVDC grid. The proposed architecture is applied to a real time simulation of an HVDC grid connected to multiple wind parks and AC networks where events were displayed as expected.

Electricity generation through solar photovoltaic (PV) technology has been one of the leading renewable energy generation options in the global arena and in many countries that are working to address increasing energy demand and high fuel import dependencies. Due to the feed in tariff (FIT) amendment in 2011 and decreasing costs in global PV sector, the interest in this emerging market is quickly increasing in Turkey. The aim of this thesis is to explore the prospects for development of the solar PV market in Turkey, considering residential, commercial and utility scale PV systems with rooftop or ground mounted installations. The economic situation, the energy profile, regulatory framework for solar energy and the market conditions in the country were researched. The ultimate purpose was to assess the overall conditions to attract investors, and estimate the development of the solar PV market growth in Turkey particularly in the next few years. High irradiation levels, limited domestic energy resources and high interest in license applications suggest a big potential for solar PV electricity in Turkey. However, the regulatory framework is not yet suitable for a fast growth of this emerging solar PV market in the country due to lack of political support and experience in related government functions. Despite the high interest and demand for commercial systems, the solar PV market in Turkey is expected to grow linearly as a start. This contrast with precedents in leading European markets, which experienced exponential growth at the beginning. This study shows that there is a need for performance improvement within the regulative authorities, time for stakeholders to experience the market and more comprehensive and stable legislation. However, in the long term, solar PV technology is expected to gain high competitive advantage due to improving financial conditions in the country, increase in electricity prices (e.g. grid parity has already been reached for residential systems), and cost reductions for PV components around the world.

The aim of the master’s thesis is to assess potential for implementing ICT tools to support smarter regional management of secondary construction materials. It is estimated that about 4.8-15.4 million tons of secondary construction material is generated in Stockholm every year. However the management of the material is not optimal. The methods chosen to complete the aim were based on systems analysis tools for an overview of the environmental effects from the system and a method focusing on interviews of salient stakeholders. Two new management scenarios were proposed and studied. Both scenarios included an ICT tool, where buyers and sellers can exchange secondary material via a website, call center or application. One scenario also included a medium term storage solution to store material before being allocated. The results from the systems’ analysis were mostly positive, showing a significant potential reduction in GHG emissions. Also a high potential economic profit was estimated. Most stakeholders responded positively to the proposed scenarios. However, the stakeholders also pointed out some challenges with the system. Such as the unwillingness of companies to corporate together and that planning is very sensitive to changes. Due to the major potential gain, it is recommended to continue the development of such a project with a key client as owner and large contractors as strategic business partners.