En energieffektiv geoenergianläggning kan åstadkommas genom att välja rätt systemtemperatur. Systemtemperaturerna påverkas av geoenergisystemets delkomponenter. Syftet har varit att genomföra en teknoekonomisk utvärdering av värmesystemets systemtemperatur i geoenergiprojekt. Arbetet påbörjades med en teknisk utvärdering av systemtemperaturen för att undersöka vilka parametrar som har en betydande inverkan på systemtemperaturen. Därefter genomfördes en ekonomisk utvärdering på systemtemperaturen. Den ekonomiska utvärderingen utfördes genom att utvärdera olika systemtemperaturers livscykelkostnad (LCC) i en referensbyggnad. Resultatet visade tydligt att LCC ökar med sänkt framledningstemperatur. Vid systemtemperaturer över grundfallets systemtemperatur som har framledning-/returtemperatur på 40/30 °C, sjönk LCC med 1–2% per grad och vid framledning-/returtemperaturer under 40/30 °C ökade LCC med 6–8% per grad. De faktorer som hade störst inverkan på systemtemperaturen var byggnadens värmebehov, byggnadens utformning och slutapparaternas effektivitet. Dessa faktorer avgör hur låg systemtemperatur som är möjligt att implementera i en byggnad.

The Swedish hydropower needs to be adapted to new legislation requiring modern environmental conditions according to the EU Water Framework Directive. A national strategy suggests how to balance the need for improved ecological status to the need of hydropower and was submitted to the Government in October 2019. To make the adaption towards sustainable hydropower in Sweden, the Älvkarleby power plant needs environmental measures as fish passages to improve connectivity as well as an environmental flow in Kungsådran. The Water Authorities suggests environmental measures in Älvkarleby consisting of a nature-like fishway for the fish to move upstream, a net for guiding the fish downstream and an increased flow in Kungsådran to 20 and 30 m3/s for winter and summer, respectively. In addition, suggestions of measures have been formed by Vattenfall based on the results of a pilot study in the Dal river creating eight scenarios. The scenarios consist of combinations of two different techniques for fish passages (nature-like fishway and a technical fishway), two techniques for guiding the fish downstream (angled bar racks and a net) and two suggestions of flows in Kungsådran; keep the flow in today’s level of an average of 3 and 12 m3/s (for winter and summer, respectively) or 7.5 m3/s all year. In this study, the suggested measures are valued in a cost-benefit analysis (CBA), that includes all expected consequences for the suggestions given in the chosen time periods, to evaluate their socio-economic profitability. A CBA tool based on a research project called FRAM-KLIV is used to receive the net present value of the suggested measures. The results show that the measure suggested by the Water Authorities is not found to be socio-economic profitable, when compared to today. This analysis has not been able to monetarize two of the identified consequences. In the CBA eight scenarios are compared to the suggested measure by the Water Authorities, Scenario 1 is valued to be the most socio-economic profitable. Moreover, there are only two Scenarios (number 4 and 8) that is evaluated to not be socio-economic profitable. In this part there is one identified consequence that has not been monetarized. There are uncertainties in the methods of estimating the consequences, which are used as input in the CBA tool, thus affecting the result. In conclusion, to have a trustworthy result there is a need of more thorough investigation for the evaluation to be used in decision making of which measure is valuated to be socio-economic profitable.

The main purpose of this thesis was to evaluate the energy use and the potential for energy savings in the ventilation for a hotel building that has been preliminary certified in the Swedish environmental assessment method Miljöbyggnad. In the preliminary certificate the building received the certificate SILVER for the energy use. This certificate needs to be verified in order to acquire the final certificate. The energy use was determined with data from energy meters and statistics from the energy provider. The potential for energy savings in the ventilation was evaluated by analyzing the effects of air flows, room temperature and supply temperature on the energy use and the room climate with the help of the simulation program IDA-ICE. The results show that the energy use in the building is 119 kWh/(m2, year), which equals the certificate BRONS in Miljöbyggnad. The certificate for SILVER will not be achieved. The biggest energy consumers are the heating system, the hot water system and the cooling system. They stand for 36, 21 and 19 percent of the total energy use, respectively. With energy savings measures in the ventilation the energy use can be reduced by 8 kWh/(m2, year). This would mean that the energy use can be reduced to 110 kWh/(m2, year). The building would still receive the certificate for BRONS. The energy savings, however, would be achieved by using a lower supply temperature, minimum air flows (0,1 l/(s, m2)) when rooms are not used as well as decreasing the time schedule for the ventilation by two hours and allowing the maximum temperature to rise by 0,5 degrees Celsius. This also resulted in a higher temperature in the conference rooms, where the temperature could reach up to 24,2 degrees Celsius in winter and 24,5 degrees Celsius hot summer days.

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Renewable energy and sustainable use of natural resources are two important aspects of sustainable development. Biogas production contributes to this since the gas is considered to be a renewable and non-fossil fuel. In addition, the production of biogas results in a nutrient- rich substance, called digestate. Biogas is produced at large-scale or at farm-level. However, large-scale production is the predominant approach, which means that most biogas techniques available are adapted to large biogas plants. For that reason, there is potential for development of farm-level biogas plants. On behalf of Gunnar Bech, chairman of the innovation group Innovationsverket in Gamleby, a new design of farm-based biogas plants has been studied. The purpose was to examine whether the design has potential to be more optimal than existing farm-based biogas plants with comparable size and capacity. The study was focusing on material consumption and energy efficiency. Initially, an extensive literature review was carried out. The biology of the biogas process and important components of existing farm-based biogas plants are described in the review. Moreover, a model of the new design was constructed. This model comprised of six small digesters, each with a volume of 200 m3, which were placed in a building. The roof of the building was used for a solar power system with the aim to contribute to the heating requirement of the biogas plant. An external heat source in form of a pellets boiler covered the remaining heat demand. Based on this model, the thickness of insulation and the solar power system were dimensioned. Besides, the annual heating demand was calculated. All calculations were performed using the program Matlab and they were based on assumptions and simplifications. In order to evaluate the potential of the new design, similar calculations were made for a reference model, which represented an existing farm-based biogas plant with the same size and capacity. The results showed that the new design required more material compared to the reference model. Depending on the circumstances inside the digesters and the building, the new design required between 170-300 m3 more insulation than the reference model. Furthermore, the results indicated that it is advantageous from an energy point of view to place several small digesters inside an insulated building, provided that solar panels are installed on the roof. This was because the annual contribution from the external heat source decreased due to the solar panels. The results showed that the annual heat generated from the external heat source was 50-70 MWh lower compared to the reference model. However, the study showed that it was not optimal from an energy perspective to mount solar panels on the whole roof surface if the excess heat could not be utilized. On the basis of the results, the conclusion of the study was that the new design has potential to be a sustainable solution for farm-scale biogas production. The results indicated that the emissions of greenhouse gases were greater for the new design during the first years of operation compared to the reference model. On the other hand, the total amount of emissions was lower in a long-term perspective. After about 7 years, the new formation was better from an emission point of view compared to existing farm-based biogas plants. However, more studies are required to determine whether the design can be implemented or not. / Förnybara energikällor och effektivare hushållning av resurser utgör två viktiga byggstenar i riktning mot en hållbar utveckling. Biogasproduktion är en del av detta eftersom biogas betraktas som ett förnybart och icke-fossilt bränsle. Dessutom resulterar produktionen i den näringsrika rötresten biogödsel som möjliggör recirkulering av växtnäring och organiskt material. Biogas kan produceras storskaligt eller på gårdsnivå. Idag är den storskaliga produktionen dominerande vilket medför att dagens tekniker är anpassade till stora biogasanläggningar. Av den anledningen finns det utrymme för utveckling av småskaliga biogasanläggningar på gårdsnivå. På uppdrag av Gunnar Bech, ordförande för Innovationsverket i Gamleby, har en ny utformning för gårdsbaserad biogasproduktion studerats. Syftet var att fastställa om denna utformning kunde göras mer optimal ur ett hållbarhetsperspektiv jämfört med befintliga gårdsbaserade biogasanläggningar av samma storlek och kapacitet. Framförallt studerades den nya utformningen ur material- och energisynpunkt. Inledningsvis genomfördes en omfattande litteraturstudie. I denna beskrivs bland annat biologin bakom biogasprocessen samt de centrala komponenter som förekommer i befintliga gårdsbaserade anläggningar. Därefter konstruerades en modell av den nya utformningen. Denna bestod av sex mindre rötkammare med vardera volymen 200 m3 som placerades i en byggnad vars tak nyttjades för ett solenergisystem. Avsikten med solenergisystemet var att bidra till anläggningens uppvärmningsbehov. Resterande värmebehov täcktes av en extern värmekälla i form av en pelletspanna. Utifrån modellen dimensionerades anläggningens isoleringstjocklekar och solenergisystem. Dessutom beräknades det årliga värmebehovet. Samtliga uträkningar genomfördes i Matlab och baserades på antaganden och förenklingar. För att utvärdera utformningens potential genomfördes motsvarande beräkningar för en referensmodell som representerade en befintlig gårdsbaserad biogasanläggning av samma storlek och kapacitet. Resultaten visade att den studerade utformningen erfordrade mer material än referensanläggningen. Beroende på förhållandena i rötkamrarna och byggnaden krävde den nya utformningen mellan 170-300 m3 mer isolering än referensanläggningen. Vidare indikerade resultaten att det är fördelaktigt ur energisynpunkt att placera flera mindre rötkammare i en isolerad byggnad förutsatt att solfångare installeras på byggnadens tak. Detta berodde på att solfångarna bidrog till att det årliga tillskottet från den externa värmekällan minskade. Resultaten visade att det årliga värmetillskottet var mellan 50-70 MWh lägre för den nya utformningen jämfört med referensanläggningen. Studien visade dock att det inte var optimalt ur energisynpunkt att installera solfångare på hela takytan om överskottsvärmen under sommarhalvåret inte kunde tas om hand. Sammantaget drogs slutsatsen att den nya utformningen har potential till att bli en hållbar lösning för biogasproduktion på gårdsnivå. Resultaten pekade på att utsläppen av växthusgaser var större under de första åren för den nya utformningen jämfört med referensanläggningen. Däremot var de totala utsläppen lägre ur ett långsiktigt perspektiv. Efter omkring 7 år uppskattades den nya utformningen vara bättre utifrån utsläppssynpunkt jämfört med befintliga gårdsbaserade biogasanläggningar. Däremot krävs vidare studier för att fastställa om utformningen är implementerbar eller inte.

Passive gains are becoming essentials with the introduction of new buildings thermal regulations. To optimize such gains, districts ground plan have to be based not only on urban consideration, but on bioclimatic considerations as well. Bioclimatism first purpose is to take advantage of the local climate and modify it if needed to obtain as much passive gains as possible for the building performance and interior comfort to be improved. The second one is to create a good exterior climate and pedestrian comfort. In fact, the first total factor of energy savings is the density of buildings. It is then of the greatest importance to attract population downtown by offering comfortable exterior spaces that can compete with more rural areas. This thesis will then focus on the wind flows impact on the outdoor and pedestrian comfort. To conduct this research, some points need to be clarified. First, what is the optimum scale to study and adapt the climate to our needs? The scale of the district had several advantages compared to a city or a dwelling scale: it is a representative city sample, its scale is reduced enough for limited data quantity to allow the evaluation of the development decisions impact on the building performance, it has a reduced number of decision makers diminishing the decision complexity and a certain amount of freedom remains allowing to adapt at best the local climate to the project needs. Second, who will be the actors of the bioclimatic conception during the project? The planner and the conception team are ubiquitous during a district conception phase and have a central position in the decision making. Hence, it is with them that the integration of the bioclimatic approach will be the more effective. Third, the success of the thesis is based on the capacity to make the heat engineers and the conception team exchange on the subject of bioclimatism. As a result, it had to be realized in a company possessing at least heat engineers and one of the conception team professions. The French company SCE, part of the Keran group, offered such environment with urban planning and energy and building activities. The process of the study was the following. A benchmark was made on the existing software that could be use by the company to realize pedestrian and outdoor comfort analysis. Then, an outdoor comfort study was made on a district construction project in the French town of Cancale. The project buildings impact on one another was analyzed. For each high frequency wind incidences, simulations were run first in 2D dimension and second in 3D dimensions. Based on the wind speed values inside the district zone calculated by the software, discomfort zone had be highlight. According to the level of discomfort, the installation of different wind breakers type was recommended.

Ground Source Heat Pumps (GSHPs) are relevant systems for space heating and cooling, very common in Sweden since 1970s. More than one million heat pumps have been sold by Swedish companies. The Energy Technology Department of KTH is working on the optimization of such application in the context of EFFSYS+ which is a national swedish project to keep the industry in a front position for the refrigeration systems and heat pump technology by a strong cooperation with the research institutes. Thermal Response Tests (TRT) were in earlier years developed in order to give an estimation of the average thermal properties of the ground over the length of the borehole heat exchanger (BHE). Further studies have been recently carried out using Distributed Thermal Response Tests (DTRT) based on temperature measurements along the borehole depth. This test permits the determination of the local ground thermal properties and local thermal resistances inside theborehole, which may be essential in the design of large Ground Coupled Heat Pump system (GCHP). A DTRT may provide information about different rock types, presence of groundwater flow and rock fissures, influence of surrounding buildings on ground temperature, among others. The analysis of the measured temperatures has been done previously using the so-called Line-Source model considering a stratified subsurface. In order to compare with the analytical approach, this numerical work simulates the ground with the commercial software COMSOL taking into account the temporal variations of the heat injection rate. An optimization module using a global least square approach is implemented to get a model which fits best the experimental data.

The primary water sources of twenty million people in Bangladesh are contaminated with arsenic; almost sixty percent of population does not have access to electricity, and close to ninety percent of the population cooks with solid fuels. These statistics have severe health and development implications for Bangladesh. Polygeneration technology is being developed that can address all of these issues with a single system, by utilizing the exhaust heat from a biogas electricity generator to remove arsenic from water via membrane distillation and using excess biogas as a cooking fuel. History is full of stories of investment in developing countries gone horribly wrong. Thorough market research and analysis can help prevent that in the future. This thesis demonstrates the process of determining beneficial components of business models for the deployment of polygeneration technology in Bangladesh. This involves understanding the existing business models used for providing rural services in Bangladesh and assessing which of these models would be more sustainable for biogas based polygeneration systems within the socio-economic and institutional context of rural Bangladesh. This is achieved through the development of a set of sustainability indicators and an interview questionnaire for providers of rural services in Bangladesh, which was applied during a field study in early 2013. The sustainability indicator scores were calculated and analyzed in the context of strategic management tools, such as the Business Model Canvas. The combination of the quantitative and qualitative aspects of these case studies highlights crucial business model elements. Based on the results of the sustainability indicators for the field sites included in the study, community and cooperative business models provide a sustainable structure for the multiple products and inputs inherent in a polygeneration system. They have the ability to reach a wider customer base and are not focused on maximizing their profit, but still make reasonable economic choices.

The Oil and Gas (O&G) Industry has been one of the most environmentally questioned sectors in the lastdecades, where the management of the resources and impact over natural life has been severelycriticized. There are many adverse effects of the activities around the O&G business, from which theconsumption of energy and the emissions of Greenhouse Gases (GHG) stand out to be one of the mostimportant aspects to mitigate. This project studies the actual EnMS in E&P and develops measures of improvement using establishedmanagement tools in the division, applying the principles of the ISO 50001 Standard, to include energysavings and GHG emissions mitigation in the lifecycle of Repsol’s E&P operated assets. The main focuslands over three core elements: the Integrated Project Management platform for new projects, the EnergyPlanning follow-up applications, and the implementation of relevant energy audit outlines.

Miljöfrågan har blivit mer och mer uppmärksammat i media och samhället. Detta har lett att mer krav ställs på att exempelvis minska energibehovet av flerbostadshus och därmed minska koldioxidbelastningen. Syftet med denna rapport är att besvara frågeställningen ”Hur kan olika kombinationer av energilösningar i flerbostadshus bidra till att vision och energimålen för NDS uppnås?”. För att kunna besvara huvudfrågan behövs data över modellfastigheters energibehov. Detta görs genom att få data och fakta från litteraturstudier och djupintervjuer. Med hjälp av energibehovet från intervjuerna kan koldioxidbelastningen beräknas och en jämförelse över de olika kombinationerna av energilösningar kan göras. Ett av resultatet från intervjuerna var att det framgick tydligt Boverkets energikrav för flerbostadshus är för lågt satt. Detta eftersom alla byggherrarnas modellfastigheter hade väsentligt lägre energibehov än Boverkets krav samt att respondenterna tyckte att kravet antingen var rimligt eller kunde skärpas. Respondenterna tyckte generellt att fjärrvärme var ett bättre alternativ vid uppvärmning då värmepumpar drivs av el. Detta då det finns risk att marginal el används som ger högre koldioxidbelastning enligt respondenterna. Vid efterföljande beräkning blev resultatet att den bästa modellfastigheten ur koldioxidsynpunkt var ett lågenergihus med frånluftvärmepump som använder grön el. I fallet nordisk elmix hade de båda passivhusen lägst koldioxidbelastning, följt av lågenergihuset i kombination med FTX och fjärrvärme. Viljan att bygga lågenergihus som samtidigt är lönsamma var hos alla respondenterna stor. Emellertid valet över tekniken som att bygga passivhus eller lågenergihus var åsikterna både negativ och positiv. Vid frågan om hur stor viljan och intresse över ny teknik som solenergi och gröna tak visade det sig att respondenterna inte använde solenergi i nybyggnation utan avvaktar tills det blir ekonomisk hållbara och kommersiellt gångbart. Under litteraturstudien framgick det att gröna tak skulle vara en energiåtgärd eftersom uppvärmnings- och kylbehovet skulle minska. Detta till motsatt till vad respondenterna svarade, de använde inte gröna tak som en åtgärd utan främst ur estetisk synpunkt, det såg vackert ut eller om en grönytefaktor behövdes uppfyllas. Att bygga modellfastigheterna som hade lägst koldioxidbelastning kan endast bidra till att NDS:s visions mål kan uppnås, men inte ensamt göra att dessa uppfylls. / Due to recent environmental concern regarding the climate change more and more pressure is laid on restricting the energy consumption on residential buildings, primarily to lower the carbon dioxide strain on the environment. The aim of this report is to answer how different combinations of energy solutions in residential buildings can contribute to the vision and energy goals of Norra Djurgårdsstaden (NDS) in Stockholm can be achieved. To answer this question an extensive literature study was done and interviewing five constructors who are connected in the NDS project. From the constructers the carbon dioxide strain could be calculated from energy consumption values of their model buildings. One of the results from the interviews was that the limit for energy consumption of residential buildings from Boverket was too low. This conclusion is due to the fact that all respondents’ model buildings had lower energy consumption than Boverkets’ limit and the response from the respondents said that the limit was reasonable or could be stricter. The general response of the respondents was that district heating is the better choice between using district heating or heat pumps when heating. This is because heat pumps are driven by electricity and when using electricity there is a risk of using marginal electricity. After the calculation of the carbon dioxide strain, the model building with the lowest strain was the exhaust air heath pump if it was driven by environmentally friendly electricity. If the model building was using Nordic electricity mix the model building with the lowest strain was the passive houses, then low energy house with the combination of FTX and district heating. The will to build low energy building was high, if it was on the same time profitable. But the response was both positive and negative on building passive house. It was clear after the interviews that new technology like solar energy and green roofs was negative. Using solar energy was interesting but the constructors are waiting until solar energy is more profitable and commercial marketable. Using green roofs to lower energy consumption was not likely, the constructors use green roofs on esthetic reasons or if the building had restriction on green areas. The conclusion of this report is if building model buildings with the lowest energy consumption would only contribute to NDS’s vision goals, not to alone fulfill the goal.