The objective of this work was to evaluate and implement a number of energy saving functions for a specific embedded system. The functions were then grouped into a number of energy levels with known properties in terms of functionality, energy consumption, and transition time between the levels.The embedded system consisted of an AT91 ARM9 processor, GSM/GPRS modem, display, Ethernet and other peripheral units. Some energy saving methods that were considered were suspend to RAM, suspend to disk, frequency scaling, and methods for saving energy in the modem, Ethernet, USB and display backlight. The functions were grouped into levels and an interface was specified for controlling the energy level.It proved possible to get known properties within the defined energy levels, even though the paritioning of functions into these levels proved to be sub-optimal in a typical application usage scenario because it was designed for mainly energy consumption, not usage.The final result is a number of energy saving functions grouped into levels, which are controllable via an application interface. Each of the levels have a known energy consumption in both loaded and un-loaded mode..

This thesis examines the environmental benefits resulting from the choice of environmental certification scheme, with focus on energy. This was carried out by studying the measures that were implemented as a result of the certification of Sweco's three largest office buildings in Stockholm, Gothenburg and Malmö. The office property in Stockholm has been certified with the Swedish Environmental Building, Gothenburg with the British BREEAM and Malmö with the U.S system LEED.The results from the study indicate that an environmental certification can reduce the energy consumption by up to 59 percent and the water consumption by 20 to 66 percent. However; the interviews, literature study and simulations in MATLAB indicate that the size and scope of these environmental benefits depend on several identified factors: the type of building and its conditions, system selection, grade level, the choice of indicators, the ambition of those involved and when in time the certification process begins. The comparison between Environmental Building, LEED and BREEAM showed that Environmental Building for the office property in Stockholm gave the largest environmental benefit in terms of reduced energy consumption thanks to several large measures.

Energy is an important issue in the current world which significantly affects sustainability and development. Energy generation and use are major sources of CO2 emissions which is one of the most important driving factors in global climate changes. The amount of energy used in house hold section can lead to estimation of the amount of CO2 emitted within this section which subsequently would be a ground to better management and maintaining a sustainable society. This study which is a bachelor?s project in sustainable energy, deals with estimation of CO2 emission from different types of residential houses in Sweden. An extensive literature review on energy use in Sweden by different residential sectors has been conducted.

The design of the building envelope affects the energy consumption of a building. As the energy requirements for new buildings are becoming more demanding, the performance of the building envelope must be improved. Energy efficiency and durability are important attributes to consider.This report includes investigations of the building envelope, moisture and passive solar energy. It is based on the analysis of two different buildings with different designs. These buildings stand as reference for two of the companies who are working on a new, climate smart, residential area in Uppsala, Sweden.Studies and analyses on energy consumption and moisture transportation were made.

Buildings worldwide account for 40 % of the total energy use. Climate change is of increasing importance, but few are willing to reduce their standard of living or get a higher cost for the change. Energy efficiency of existing buildings gives the greatest benefit economically and environmentally. The real estate company Klövern AB manages 46 properties in Karlstad. Heating is the major cost of the total operating costs of real estate. Rising energy prices increase the need for Klövern AB to improve energy efficiency and to investigate alternative sources of heat.

The importance of energy- and environmental issues has increased, and the work towards reducing carbon dioxide emissions plays a major part. The European Union has set up goals for the membership countries to work towards this to happen. The carbon dioxide emissions in Sweden have been reduced the last few years, but there is still a lot to do. About 30 per cent of Sweden?s carbon dioxide emissions generate from energy usage related to housing, this is why the housing sector is of interest to examine.

The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage.

Calculated and measured energy in residential buildings is going to differ. The reason to this may be due to many factors. In this study there is a study on how these factors affect the energy use in a building. To get an insight in what defines energy, there is first a description of energy supply both worldwide and used in Sweden, followed by a description of the energy balance. In this study energy will be studied in residential buildings only.

The exhaust arrangement on a Scania V8 consists of one manifold at each bank connected to a twin entry turbine (8-2-2). A study in GT-Power has shown improved performance and reduced cylinder to cylinder variations using two manifolds at each bank in combination with a single entry turbine (8-4-1). This thesis work analyses the difference in performance shown in simulation and verify it by engine test.The initial work was focused on simulation in GT-Power. Investigating how exhaust manifold volume and pulses effects the turbine efficiency and the mean effective pressure during the gas exchange. To verify GT-Power simulations four engine tests with different exhaust arrangement have been made.The results from GT-Power simulation indicate that a larger exhaust volume improve the turbine efficiency.

The purpose of the study is to investigate the possible effects of an unstable ventilation system and its influence on energy use and thermal comfort. The report also explores how qualified personal working with HVAC view and handles system control.In order to meet the requirements in energy efficiency and a comfortable indoor climate control regulation is a prerequisite. With optimized increased complexity of the climate systems, it becomes more challenging to control the system and the risk of unstable control increases. No previous studies about what affect an unstable system can have on energy use and thermal comfort have been found.The report is based on several tests were the controlling variable has been increased until the system becomes unstable. Two different types of unstable systems have been investigated.

This bachelor thesis aims at investigate how a specified house can optimize its energy consumption.Today the house often stands for the major part of the energy consumption in a consumers? life,whereas an energy optimization creates economic as well as environmental advantages. It is importantto make old houses more energy efficient, but putting high energy demands on new houses could beargued to be more important. The installations functions as both the heart and brain in a house, thusmaking it important to energy optimize these. Since the background describes the importance ofenergy efficiency and optimization in a house, the focus area of this report will be an investigation ofdifferent types of heating systems in order to be able to choose the one most suited for the house.Aspects considered when choosing the heating system was how economic the system is both inservice- and investment costs and how environmental and operational friendly the system is.Through literature reviews there were sufficient information gathered that served as a foundation whencomparing and choosing between the four systems - district heating, pellet-fired boiler, geothermalheating and solar heating.

One of the city of Stockholm?s main objectives is to have a society completely free from fossil fuels. To achieve this, several investments regarding improvements in energy efficiency and renewable energy are currently being planned or implemented. One of these investments is a project called Hallbara Jarva which is located in the suburbs of Stockholm. The purpose of this thesis is to examine the prospects of an investment in photovoltaic cells from an energy-saving and economical point of view. The analysis is limited to three buildings within Hallbara Jarva and is intended for the property owner.  Solar energy is a type of renewable energy source and is commonly divided into solar heating and solar power.

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 building and plant sectors represent a large part of Sweden?s energy use. Putting energy requirements in public procurement as a tool for reducing energy consumption in the building and plant sectors is therefor an opportunity that operators can take advantage of. The aim of this thesis was to map the energy requirements in procurement that operators in the public sector use today in building and plant projects. The analysis was made with respect to if the energy requirements corresponded to the parts with large energy use in building and plant projects and also in which way energy requirements in procurement are written in the contract.

Restoration projects are planned and carried out in order to reduce the impact due to anthropogenic influence and to achieve at least good ecological status according to the EU Water Framework Directive. The resilience effort of such restorations is however ambiguous. The aim of this study was to evaluate the potential of follow up restoration measures in Swedish lakes and streams. In particular, we visualized the geographical spread of restoration measures in Sweden and quantified the different types of measures that were implemented so far. Further, we evaluated the extent of sampling of biological factors before and after the restoration measures have occurred. For the purpose of our study, we used the recently compiled national database of restoration measures in Swedish lakes and streams.