In this thesis proposals for different designs of a borehole thermal energy storage (BTES) have been developed for the building DN-huset in Stockholm, Sweden. To build a BTES results in savings in energy costs by approximately 44 %, i.e. 2 million Swedish crowns annually. Furthermore, a BTES would reduce the annual environmental impact with roughly 75-157 tonnes of CO2 equivalents per year, depending on how the electricity consumption?s environmental impact is estimated.

Sweden has formulated ambitious energy goals which signify that by year 2050 the energy usage should be halved. One of the objectives is the reduction of energy usage by 20% by year 2020 and that it should be compared to the usage of energy from 1995. In parallel with increased energy requirements for buildings the demand on housing conservation, by highlighting also buildings from the last 50 years as part of the building heritage, continues to enhance, which in theory means that there is a conflict between these.The law will never be able to point out unique buildings and PBL (planning and building act) is not especially concrete. The National Housing Board has tried to make this more concrete by the new BBR regulations though there are still an enormous variety of interpretations.This report deals with the conflict between conservation requirements and additional insulation of the building envelope and is limited to multi-residential buildings built between the years 1945 and 1975. It is the stock with the greatest energy consumption and that is where the big challenge lies.

This thesis aims at determining the heat losses in a property vent stack and its roof valve. Upon request of a company, the vent stack is analysed for possible heat recovering solutions to be implemented, while relining of the drain system is executed and with a suitable payback time for the economic investments. The heat loss calculations are based on data for properties that are located in the Stockholm region, but also easy to change depending on the situation. The calculations are done on pipes made out of cast iron, which still is the most common type of drain pipe in Sweden, and these are the pipes that relining is usually made on. The calculations that needed to take several variables into account have been done in MatlabR2014a and the thermos dynamical properties that were used in those calculations have been extracted from EES.Three different types of heat losses in the vent stack have been taken into consideration in this thesis.

The EU Council adopted in 2007, environmental and energy goals with the aim of them must be met by 2050. This, in combination with those of the Swedish government 15 enacted environmental goals is supposed to lead the way for the Swedish environmental work.This report has examined measures in properties in the Swedish Cooperative Housing Society (SKB) stocks.The report discusses a range of measures that might be appropriate to apply on the properties to make them more energy efficient.One of the measures discussed, the vent whose primary purpose is to create a good indoor environment for the residents but is also where the most energy is lost.Another measure discussed is insulation of the building envelope on the estate to make it more energy efficient. To put extra insulation on the building envelope is important because of the large amount of energy that is lost through the walls, ceilings and floors.Future actions that may be implemented is individual billing of heating and hot water. This system has been used in European countries since the 70's and today the EU wants to increase the own individuals control over their electricity costs. This has led to a discussion whether to implement the system in Sweden or not.However, there are a number of equitable measures to be sorted out before the system can be used in any great scale.Finally, it is important to remember that environmental measures should be the primary and the pursuit of cost reductions the secondary otherwise you risk the environmental work to be counterproductive..

At Uppsala university scientists have during the last years developed and built wave energy converters. This project is called "Lysekilsprojektet". The development has come so far that they are currently investigating how to gain profit in a mass production. For that reason they want to automate as many steps in the production as possible.The winding of the stator is one part that is being automated using industry robots. The stator is cable wound unlike many other generators.

An energy study has been performed on two blocks in an area called Gävle Strand. The buildings are owned by a tenant-owner?s association called brf Carolina and were built by the company Skanska 2008. The builder as well as brf Carolina are pussled by the fact that electricity use is higher than expected while heating is less. Skanska is also very interested in finding out how much heat recovery from stale exhaust air through a geo-thermal heat pump is contributing to the general heating requirement and energy balance in four out of the ten buildings located on the properties.To find possible answers to the higher electricity use a literature survey on user behaviour was conducted.

An energy study has been performed on two blocks in an area called Gävle Strand. The buildings are owned by a tenant-owner?s association called brf Carolina and were built by the company Skanska 2008. The builder as well as brf Carolina are pussled by the fact that electricity use is higher than expected while heating is less. Skanska is also very interested in finding out how much heat recovery from stale exhaust air through a geo-thermal heat pump is contributing to the general heating requirement and energy balance in four out of the ten buildings located on the properties.To find possible answers to the higher electricity use a literature survey on user behaviour was conducted.

The Swedish government has introduced a goal to reduce the energy intensity by 20% to the year 2020. To reach this goal actions need to be taken throughout the energy sector which includes residential and commercial buildings. This thesis considers the possibility to reduce the energy usage in a building located close to Uppsala. The analyzed building is a combined office, cafeteria and entrance and was completed about half a year before this project started. Therefore the measures presented for a more energy efficient building are presented as measures for future constructions.Simulations have been made in VIP-Energy, a dynamic energy calculation program.

Background: The most energy efficient houses today are so called passive houses. These houses achieve high energy-efficiency partly by having well insulated walls. U-value describes the amount of heat transfered through a building element, the more insulation, the smaller U-value. A typical passive house wall have a U-value of 0.10 W/m2,°C. The passive houses are primarily made as small family houses and not as a block of apartments.

As break downs of production transformers are costly and often result in long outages it is essential for reliability of operation that the transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.

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.

A lot of houses built during the Million Homes Programme are in need of major renovation. Today?s technology and materials are better than in the 60?s and 70?s. Both Swedish government and the European Union have set climate goals regarding energy consumption by 2020 and 2050. Achieving these goals would require better standards in buildings than the Building regulations demands, such as Umeå municipality?s construction requirements for new buildings.The report aims to investigate if a renovation of apartment buildings from the Million Homes Programme can reach Umeå municipality?s construction requirements.

When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.

The district heating load is seasonally dependent, with a low load during periods of high ambient temperature. Thermal energy storage (TES) has the potential to shift heating loads from winter to summer, thus reducing cost and environmental impact of District Heat production. In this study, a concept of high temperature borehole thermal energy storage (HT-BTES) together with a pellet heating plant for temperature boost, is presented and evaluated by its technical limitations, its ability to supply heat, its function within the district heating system, as well as its environmental impact and economic viability in Gothenburg, Sweden, a city with access to high quantities of waste heat.The concept has proven potentially environmentally friendly and potentially profitable if its design is balanced to achieve a good enough supply temperature from the HT-BTES. The size of the heat storage, the distance between boreholes and low borehole thermal resistance are key parameters to achieve high temperature. Profitability increases if a location with lower temperature demand, as well as risk of future shortage of supply, can be met.

This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions: ? Can U-value theory be combined with acoustic theories? ? Can the coefficient of heat be affirmed trough an acoustic measurement? The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units. The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory. The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB.