Biogas is increasingly used for fuel in for example vehicles and it´s produced in a biogas processconsisting of the steps of pretreatment, digestion and gas cleaning. The pretreatment is a method usedto increase the gas production and / or destroy pathogens. The digestion is the stage when anaerobicmicroorganisms convert bio-mass of a substrate to a raw gas containing about 65% of methane. Thegas cleaning is used to increase the methane content to about 97% so the gas can be used for motors invehicles. The biogas part of the Ekeby sewage plant in Eskilstuna is using multiple substrates.

The concept of planetary boundaries was introduced in the year 2009 by a group ofresearchers led by Johan Rockström and Will Steffen. The group presented a draft of thelimits of the planet regarding nine Earth System processes concerning climate change, oceanacidification, stratospheric ozone depletion, atmospheric aerosol loading, interference with Pand N cycles, global freshwater use, land-system change, rate of biodiversity loss andchemical pollution. The starting point for the study presented in this report was that asustainable development only can be achieved if humankind stays within the boundaries. It istherefore, based on the ongoing urbanization, relevant to evaluate how cities affect the EarthSystem processes. The aim of the study was to investigate if Stockholm Royal Seaport (NorraDjurgårdsstaden), a district in the northeast of Stockholm with a clear environmental profile,affects the Earth System processes less than Stockholm in general does.

The Swedish energy companies have several different systems for data collection of the energy consumption of their clients. Often computerized remote meter readers are put in practice in order to register the energy consumption of large companies. The majority of household clients, however, are read off by the assistance of manual methods. Household power consumption is read off once a year. As a result, these clients are not debited for their actual consumption; their invoices during the year are the result of estimations. At times when the electricity supply system is highly loaded, electricity is more expensive.

In recent years, moisture damages have been noticed in rendered, undrained stud walls. The design is built on the principle one-stage tightening which means that there is no air gap in the construction. The damages have occurred when water has permeated through the rendering in leaking connections and fittings for windows, doors, canopies, balconies, terraces and awnings. Behind the plaster carrier, which consists of either polystyrene or rigid mineral wool, plasterboard has often been used as a wind protection barrier. In many cases the wind protection barrier and the underlying wooden studs have been exposed to mould and in some cases even rot.

This Master degree project has been performed at the Braviken paper mill on papermachine 53 (PM53) which produces newsprint paper. The current economic situationhas contributed to declining demand for newsprint, which means it is extra important tobe competitive by high energy efficiency. Particularly as energy prices are expected torise when the economic growth returns.One way to increase energy efficiency is by reducing the water use in paper and pulpmills and consequently save energy through reduced heating of water. The thesis's maintask is to evaluate whether a water purification plant (microflotation plant) forpurification of process water in PM 53 is profitable. The microflotation plant enablesreuse of warm process water instead of losing the energy to receiving waters.

The use of energy is an important question in today´s society, and a substantial part of the energy that is used today is used in our homes. To lower this usage is vital, and there are regulations in place both on the national and the local level, that say that new apartment blocks must be built to consume less energy, which in the end will lower the impact on the climate.One way to make the housing sector more environmentally sustainable, is to produce energy issions that are bad for the environment, for example to build wind turbines close to or even on the buildings, so called urban wind power. The scope for this report is to see if urban wind power could be a sustainable alternative for the residential area that Svenska Bostäder plans to build in Albano in Stockholm.There are extensive scientific theories regarding wind and wind power, and a literature study is made to investigate past knowledge in the area. Efforts have been made to find earlier trials with urban wind power and, both scientific research and trials where urban wind power actually has been installed. The theory chapter deals both with the wind itself and how electricity can be generated from wind.

The project has sprung out of my imagination. I wanted to find out what happened to my creativity, and my way of making product design if I used the method of putting myself into a fictive world. The project has taught me to rely on myself and my knowledge as a designer.I have made a chair which closes out sounds and gestures in public places. A chair which provides you with peace and quiet in a busy environment..

In recent years it has become more and more evident that man has contributed to much of the climate changes that have taken place during the last century. A major challenge today is to reduce emissions and energy usage at the same time as the global population is growing. To contribute to a better environment, Stockholms Stad has set at target of becoming fossil fuel free by the year of 2050. The construction of new districts is done with this goal in mind; energy efficiency and renewable energy sources are examples of methods to achieve this.Solar energy is considered to be a sustainable energy source and the most common techniques to harvest solar energy in Sweden are solar cells and solar collectors which produce electricity and heat respectively. This report aims to investigate whether an investment in any of these systems would prove to be economically beneficial at Kvarnholmen, a district under construction in eastern Nacka, Stockholm.Since the finished blueprints only cover a small portion of Kvarnholmen, the report examines the possibilities for a house where construction has already begun, Nya Kvarnen.

Mechanical ventilation is the most common type ofventilation in newly constructed office buildings. Therehas been an interest to utilize natural ventilationinstead of mechanical ventilation among architects andHVAC consultants in recent years. This is due to thesize of mechanical ventilation systems, which arespace consuming. The mechanical ventilation system isalso complex and requires maintenance. Furthermore,the fan uses a considerable amount of energy.

The purpose of this study is to investigate how much of the estimated annual electric energy production from Swedish wind power that actually was produced, as well as the history of this agreement over time. The aim is to also examine if there are properties that have caused some group of wind power plants to produce more or less, compared to their estimated production. Operational data on wind turbines collected by the Swedish Energy Agency was analyzed. A survey was made among owners of wind power plants with a nominal power of at least 2 MW. Two different methods for normal year correction of production data were used and compared.

The use of fossil fuels such as coal and gas are a contributor to the global warming. The climate change is a worldwide problem with far reaching consequences that is believed to be very expensive. The United Nations has been introducing a framework convention on climate change. One component of the convention is the Kyoto protocol. The protocol is obligating the developed countries to decrease their emissions of greenhouse gases by 5.2 percent during the time period 2008-2012.

Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.

The energy consumption continues to increase as the use of electronics and energy consuming equipment increases. The use of fossil fuels has to be phased out for this to be sustainable in the long run while the use of renewable energy continues to increase. A renewable energy source is solar energy but the production of heat and electricity are today very expensive compared to other energy sources and an important task for the solar energy market to grow is therefore to minimize the production cost of the solar collectors while increasing its efficiency to produce heat and/or electricity. One way to convert solar energy into heat is by using solar collectors and electricity can be produced by utilizing the produced heat, or by applying solar cells.This thesis aims to recommend a reflective material for the next generation solar collectors from Absolicon and to recommend a commercially available coating for the receiver tube of the solar collector. A market study has been carried out to investigate the cost-related aspects along with the optical and durable aspects for the optical material of the solar collector.

The project was performed at SiemensIndustry Drive Technologies with theobjective to provide actual values forthe energy savings potential withinSiemens scope of practice.In Sweden the electrical drives standfor about 30 % of the total electricityconsumption and about 60 % of theelectricity consumption within theindustry. During the pre-study phaseelectrical drives with pump applicationswere identified as large energy users.Because of this a case study at one ofSiemens customers, Stora Enso Fors wasperformed. The system that was evaluatedduring the case study was a throttledsystem with a centrifugal pump forpumping pulp.The results yielded that a saving ofover 50 % could be achieved by replacingthe throttle valve with a variable speeddrive, a frequency converter. Thepayback period was two years and twomonths and the present value for thetotal life cycle cost of the variablespeed system was 662.566 SEK lower thanfor the throttled system. As aconsequence, Stora Enso Fors is advisedto invest in a frequency converter forregulation of the system.The general conclusion is that a focuson system efficiency is the mostimportant factor in energy efficiencyprojects and that the system regulationmethod has a large impact on the overallsystem losses and hence its efficiency.Energy efficiency potential forthrottled systems with centrifugal pumpsis large and significant economicalsavings can be made through investmentswith short payback time..

AbstractThe real estate sector is today responsible for 40 per cent of the total amount of energy consumption within the members of the EU. All over the world there are collaborations within research and projects to find ways of reducing the amount of energy consumed by the real estate sector. In Sweden, a directive from the European Union has posed demands on authorities as well as on the private sector to reduce the amount of energy consumed by new building constructions. Together with the directive from the EU there are also new requirements and demands from Boverket for the real estate sector.  These requirements mostly concern the energy consumption of kilowatt-hour per square metre and that the consumed energy also should be renewable.  The aim of this study is to explain what kind of value municipalities experience in using certifications and environmental investments for new and existing buildings. Within the chapter theory, essential areas are described such as; environmental certification systems, economical viability, proceeds connected to building green, difficulties with building green, the performance of green buildings when affected by the behaviour of tenants and customer value.  The following chapter describes the methodology with which we have conducted this study.