Globally, buildings utilize 35 % of the final energy use and contribute to approximately one-third of CO2 emissions. Hence, reducing the energy use of buildings contributes to a large amount of CO2 emissions to be decreased. The building’s energy use is affected by many parameters, including wind which plays an important role in building energy use. In this thesis, we aim to analyze the impact of wind parameters on building’s energy use on two multi-family building types with natural ventilation at various wind sheltering conditions at different climatic zones in Sweden. Building energy simulation models (BES) of a standalone and an attached building located in Visby, Sweden, were constructed with the use of the dynamic BES IDA ICE. Luleå and Malmö were taken as other two study locations to investigate the impact from different climate zones. The simulations were performed with the constructed calculation models, with the various wind sheltering conditions at the different climatic zones to calculate the energy use of the buildings and ventilation and infiltration losses. The sensitivity analysis was then carried out based on changing the wind profile of the climate file to evaluate the impact of wind on the ventilation and infiltration losses, as well as the heat energy use of the building. The results showed that the energy use for space heating of the attached building was 89 kWh/m2 (38 %) lower than the standalone building. The energy use varies between 9–20 kWh/m2 (3–10 %) considering the exposed, semi-exposed and sheltered wind condition for the two building types. In the different climate zones, Luleå has 47 kWh/m2 higher energy use compared to Visby and Malmö for the standalone building. The corresponding figure for the attached building is 25 kWh/m2. The sensitivity analysis show that when the wind speed is increased by 100 %, the ventilation and infiltration losses increase between 3563–18683 kWh (54–61 %) while the energy use of the building increases between 11–54 kWh/m2 (20–27 %).

The aim of this thesis is to increase the understanding of small-scale green energy technology development. In the transition towards a fossil free energy system, heat pumps are a low emission heating alternative. Contrary to other types of new small-scale green energy technology such as solar cells and electric vehicles, heat pumps are established on the Swedish market, with more than half the share of single family buildings. This makes it possible to study an example of a mature technology, and that knowledge could be used in the development and deployment of other technologies with similar small-scale green characteristics. The type of heat pump technology studied is ground source heat pumps, and their development is explored from an economic and performance perspective, using the concept of learning. Learning tracks how a product develops for each doubling of units produced. The results show that the efficiency has increased by a learning rate of 2.8 %. When the effects of a low-temperature heating system is included, the learning rate is even higher, 5.8 %. The efficiency improvement is mainly due to new and more expensive components, which has resulted in a price increase. Even if the price slightly decreased until 2008, it has increased with 29 % since. Nevertheless, the ground source heat pump is profitable compared to several other heating technologies. The most important factors underpinning the development are regulations, competition among manufacturers and research.

Hydropower plants with spillways exposed to high pressures because of large discharges can result in a dam failure which ultimately results in devastating consequences. Therefore properly designed and constructed spillways are important. In this project there is an interest in examining the pressure distribution on a guided wall, measuring the water level inside the spillway and examine the water flow characteristics. The main purpose was to numerically model the flow behaviors at two upper pool levels +29.82 m and +30.92 m in order to achieve a comparison between a numerical model and a physical model. A previous experiment was carried out at Vattenfall R&D in Älvkarleby where a physical model was built. The main purpose of that study was to find an optimal form of a guide wall for free weir flow. This study served as guidelines for what should be investigated in this project. The methodology of the project began with a development of an initial CAD model created by Vattenfall R&D. The CFD model could be constructed into a volume model containing also an upstream reservoir. Next, a mesh that could numerically calculate the flow behavior was created in order to enable execution of the calculations. Furthermore, a big part of the method was to adjust the settings in Fluent so that the numerical model could recreate the flow behaviors of the physical model tests. The results indicate that the numerical model is an accurate replica of the physical model. The deviation comprising the mass flow rate came as close as 0.6 % from the physical model for the lower upper pool level. Highest calculated pressure was positioned at the bottom of the guided wall for both upper pool levels, which the results conducted from the physical model also indicated. Furthermore, results regarding the water level at the guided wall confirmed same statement Vattenfall's examinations pointed out, that the roof placed at the guided wall is needed in order to avoid major splashing. The present project has shown great results regarding the flow characteristics, pressure distribution, and the water level at the guided wall. Therefore, it is considered trustworthy enough to be used as a tool for Vattenfall R&D in future studies comprising the targeted spillway.

There is a large potential in making the residential and service sector more energy efficient and the first step towards achieving a more efficient use of energy is to implement an energy audit. In this study a property with an approximate area of 8 000 m2, consisting of a main building and three building extensions from different eras has been examined. The main building and its extensions were built in different stages and the first one in the early 20th century and some parts of the last building extension were modified at the time that the examination was carried out. This indicates that there is a vast energy savings potential in the property and an energy audit was performed. The main aim of the study was to examine where the energy was being used and where energy could be saved. Energy saving measures has been suggested together with a calculated approximate energy decrease and payback period. The total energy savings potential for the measures is approximately 146 MWh. The energy audit showed that a large amount of electricity was being used during non-work hours and that energy was lost through the building envelope. The electricity use during non-work hours was examined during the night walk, however, it is suggested to carry out further examinations regarding the property’s vast electricity use during non-work hours. To add loose wool in the roof of B2 has an energy savings potential of 33 000 kWh/year. Another measure is to clean the heat exchangers, this measure has an energy savings potential of 26 000 kWh/year. Also it is suggested to optimize the operational hours for the lighting by implementing presence control and to decrease the energy use for ventilation by cleaning the heat exchangers. Further examinations that would improve the study would be to do measurements of the electricity and temperatures to get a better understanding of the buildings energy use. Also to model the building in a simulation tool would give a calculated energy loss that is more like the actual energy loss of the building and make the results more reliable.

The district heating system (DHS) of Stockholm is one of the largest systems in the world with a total yearly production of 10TWh of heat and 2TWh of electricity (through combined heat and power plants). Large amounts of greenhouse gasses (GHG) are emitted to produce this heat and electricity. Given the goal of the City of Stockholm to reduce the amount of GHG emissions to 3 ton per capita in 2015 and to keep reducing emissions at a similar rate after 2015, it is important to identify the potentials for further reductions. Numerous studies have been done on how the DHS can become more sustainable by installing new generation units. However, also the consumers have an influence on the DHS. After all, it are the consumers who decide when and how much heat or electricity they use. Most former studies and environmental guidelines for the DHS in Stockholm focussed on the producer side. This thesis looks at the consumer perspective of the (heat of the) district heating system. A real-time signal giving the greenhouse gas emissions of individual households is developed and its potential and challenges are discussed. With this signal, households that want to minimise their environmental impact have a tool to decrease their environmental impact by changing their consumption. This can be a first step to transform the DHS to a smart district heating system. First, generic models to calculate the dynamic greenhouse gas intensity of the heat production of district heating and to calculate the greenhouse gas emissions related to the heat consumption of households are suggested. Then the feedback signal with those real-time household emissions is calculated for representative households in Stockholm based on data of Stockholm’s DHS and data about hot tap water consumption in Sweden. Results indicate that variations in household level greenhouse gas emissions mostly reflect changes in consumption but can also result from changes by the producer. Intraday variations are mostly caused by changes in hot tap water consumption, while variations on a timescale of a few days are caused by changes in heating consumption (changing weather) and changes made by the producer (to use different fuels). Then several scenarios are calculated, each scenario looking at the actions a consumer can take to shift or reduce his/her consumption (decrease hot tap water usage, lower indoor temperature etc.). The real-time household emissions are calculated again to see if the signal gives the needed incentives (is the household rewarded for its effort? Does it get further incentives?). It was found that a strong time-incentive (to decrease consumption when it saves most emissions) is missing if the average perspective is used to calculate the emission intensity of the heat production. Also, the results confirmed the finding that the feedback signal might not reflect changes in consumption. Finally, challenges for the signal are discussed. One of the major hurdles is the fact that household consumption of heat (heating and hot tap water) can often not be measured on a household level. Thus, it has to be estimated but it seems very difficult to get this estimation accurate enough to give correct feedback to households, especially about the emissions saved by their efforts to reduce/shift their consumption. Secondly, the time resolution should be chosen well to still get accurate results but not make the signal to data-intensive. Finally, the result is heavily dependent on the chosen methodology (average or marginal perspective? Do you account for the electrical side of the DHS? How about the distribution losses? Etc.).

A turn to more sustainable resources has lead the research during the last decades to algae. Algae is a resource that has been utilized for thousands of years offering a variety of possibilities. Nevertheless modern technology were able to uncover algae’s great potential and pave the way for alternative uses such as biofuel and biomaterial production. Towards that direction, ‘Seafarm’ aims in utilizing algae in the most efficient and sustainable way. For that purpose various steps have been established, including the biorefinery step which entail among other the extraction of carbohydrates from brown algae. The current thesis is based on an extraction of carbohydrates from Saccharina latissima, a brown algae species, which was developed by Viktor Öberg during his master thesis at KTH. The aim of this work is to assist in the scaling up of that laboratory process by analyzing the basic steps and substances of the process, investigating its environmental performance and identifying improvement areas for theoretical optimization. The results of the aforementioned analysis include a substance flow analysis which reveals the basic steps of the process and constitute the basis for further analysis. The second step examines the environmental performance of the process based on the chemical selection. Hence the results are a risk assessment of chemicals with performance indicators for each chemical as well as the whole process. The final part provides a theoretical optimization of the process based on literature studies where the recommendations are divided in production optimization and environmental performance. The above results constitute the basis of the analysis of the process and sets the foundations for scaling up the process at an industrial level. The current analysis in combination with an energy and economic assessment could be used for the designing of the process and its integration in the biorefinery.

This report discusses the ambition of EDF, a French electricity provider, to offer new services to its customers. With the emergence of the smart grid that will be operational in 2020 in France, there are several opportunities that have to be taken. One of them is to be able to offer a suitable monitoring system to its customer. This study tried to emphasize the important aspects and features that are required in such a system. Several solutions that are currently being commercialized in France have been analyzed. A grading has been made according to the technical functionalities and the business models have been analyzed.  Recommendations for EDF have also been made in order to help the company to choose the right monitoring system.

“We emphasize the need to address the challenge of access to sustainable modern energy services for all, in particular for the poor, who are unable to afford these services even when they are available.”  Section 126: The Future We Want (Out Come Document of Rio+20-United Nations Conference on Sustainable Development June 20-22, 2012). The lack of energy access has been identified as a hurdle in achieving the United Nations’ Millennium Development Goals, leading towards the urge to set a goal for universal electrification till 2030. With around 600 million people in Africa without access to electricity, effective and efficient electrification programs and policy framework is required to achieve this goal sustainably. South Africa is an example in the continent for initiating intense electrification programs and policies like “Free Basic Electricity”, increasing its electrification rate from 30% in 1993 to 75% in 2010 and a claimed 82% in 2011. The case of South Africa has been analysed from the perspective of universal electrification in the coming years. The aim was to estimate the un-electrified households for each area of South Africa in order to provide the basis for electrification planning. The idea was to use available electrification statistics with GIS (Geographic Information System) maps for grid lines and identifying the suitability of on-grid or off-grid electrification options, which may help in planning the electrification of these areas in the near future. However, due to lack of readily available data, the present work has been able to estimate the un-electrified households & their possible electrical load. The estimates have been distributed in different income groups for each province and district municipality of South Africa, which can be used for electrification planning at national, provincial and municipal level.  As a result, some simple and useful data parameters have been identified and an estimation methodology has been developed, which may be employed to obtain similar estimates at lower administrative levels i.e. local municipalities and wards. The work can be utilized further and feasible electrification options may be suggested for different areas of South Africa, with the help of GIS maps and data. Depending on the availability of useful data, the data parameters & indicators used in this work will be helpful for planning the electrification for rural households in other places of Africa.

The intent of this thesis is to analyse the sustainability of producing bio-ethanol from cane molasses in Indonesia and its potential to replace gasoline in the transportation sector. A field trip was conducted in East Java, Indonesia, and data was gathered for analysis. Life cycle assessment (LCA) was performed to analyse the net emissions and energy consumption in the process chain. The greenhouse gas (GHG) emissions of the life cycle are 17.45 gCO2e per MJ of ethanol produced. In comparison to gasoline, this results in a 78% reduction in GHG emissions in the complete process chain. Net Energy Value (NEV) and Net Renewable Energy Value (NREV) were 6.65 MJ/l and 24 MJ/l. Energy yield ratio (ER) was 9.43 MJ of ethanol per MJ of fossil energy consumed in the process. Economic allocation was chosen for allocating resources between sugar and molasses. Sensitivity analysis of various parameters was performed. The emissions and energy values are highly sensitive to sugarcane yield, ethanol yield and the price of molasses. Alternative management options were considered for optimizing the life cycle. Utilizing ethanol from all the mills in Indonesia has a potential to replace 2.3% of all motor gasoline imports. This translates in import savings of 2.3 trillion IDR per year. Use of anaerobic digestion or oxidation ponds for waste water treatment is unviable due to high costs and issues with gas leakage. Utilizing 15% of cane trash in the mill can enable grid independency. Environmental impacts due to land use change (Direct & Indirect) can be crucial in overall GHG calculations. Governmental regulation is necessary to remove current economic hurdles to aid a smoother transition towards bioethanol production and utilization. / Harnessing agricultural feedstock and residues for bioethanol production - towards a sustainable biofuel strategy in Indonesia

Today, energy access is a significant challenge all over the world, particularly in African countries. At the same time, providing energy access is generally accepted as a way to promote sustainable development. In countries such as Uganda, lack of energy access is evident. In this country only 9% of households have access to electricity. About 87% of these households are located in rural and remote areas. Thus, off-grid rural electrification solutions are required to supply electricity services to a significant part of the population.The ultimate objective of this thesis is to propose a specific solution to cover basic energy needs of the rural population considering environmental, social and economic benefits. How can sustainable life solutions be provided in rural areas, by using the energy surplus from a decentralized small-scale biomass gasification power plant? The analysis used as a starting point the Green Plant Concept, which considers the design of a sustainable off-grid platform that produces energy to provide life solutions and also to excite local entrepreneurship in the rural sites where it is implemented. The concept implies participation of the private sector – a telecommunication company – which is a unique feature in the context of rural energization.To develop our analysis, a field trip has been conducted in Uganda, Africa, to answer sub-questions such as How to reach a cost-effective system? How to adapt a business oriented approach to the community’s life-style in order to be well accepted? How to foster the development of the area by having a positive socio-economic impact on society? How to create an environmental friendly solution? How to achieve the maximum efficiency in terms of reusing waste? Tools such as Multi Criteria Analysis (MCA) and SWOT analysis were used to interpret collected information and identify impacts of the suggested solutions.The research has shown the great potential of the Green Plan Concept. We conclude by selecting three applications that can enhance the provision of basic energy needs while creating benefits for the stakeholders involved in the process: i) Mini-Grid solutions, ii) Battery Charging Stations and iii) Heat Pipe Exchangers. We also highlighted the relevance of bringing, in addition to appropriated technologies, different stakeholders together, considering their common interests.The research is finalized by estimating the payback period based on the current and expected energy consumption and the capital investment related to the suggested applications. It is important to highlight that the payback time estimations do not include the participation of the telecom companies. This means that the estimated payback period of 7 years could be significantly reduced by the inclusion of this stakeholder.