To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock.The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air.

This report is a study in voltagelevel in connection with regeneration of brake energy from the tramtype M31 in Gothenburg.In the act of braking, the tram M31 uses electrical braking where the electrical motors generates energy and if possible send it back to the overheadline, where other trams in the nearby can use this regenerated energy for its own driving force. In cases where no other energyconsumers are located in the same section, there is a resistance witch task is to convert this energy into heat. The regulation of this resistance appears to cause an increase in the voltagelevel into far too high levels.Investigations of the trams regulationequipment and its construction have been done. Further have measurements on the overheadline been performed in order to map the voltagevariations during a longer period of time.The result have been showing that the voltagelevel during regeneration often is as high as 880V-920V, more extreme values have not been observed in a large scale. The values are especially high compared to the nominal voltagelevel.

As the Swedish governments long term goals include a reduction of fossil fuel dependency, increasing pressure is placed upon energy companies to create and develop new solutions for renewable energy. The following case study was done in collaboration with the company Sydved Energileveranser AB and one of their contractors, Enarssons Skogsentreprenad AB. The objective of the study is to examine the bioenergy situation in region of Skåne and evaluate the potential solutions in the region for a forest-fuel assortment, based on a bioenergy-cutting-system. As a part of this study I have compared ordinary manual cuttings done with a chain saw and cuttings made using the new ?bio- energy cutting system?. The cuttings made under both systems were tested in areas near agricultural fields or pasture land in order to maintain an open landscape.

Overall aim of this master?s thesis is to describe and identify perceived barriers in Swedish businesses within solar energy field and analyze, based on four theoretical viewpoints, how these barriers can be handled. In other words how can the barriers be overcome or eliminated to better succeed in the commercialization process? The method applied is qualitative in which data has been collected through phone interviews originated from seven Cleantech businesses which operate within solar energy. Furthermore this thesis has a descriptive- and an explorative purpose.

In modern society in terms of economics and environmental impact, it is important to ensure that a company is as energy efficient as possible to reduce the amount of energy used. About 10 TWh of electricity used annually to pump drives in Swedish industry. Therefore, pumping system has great potential for energy savings.The objective of this report was to determine how much energy and money that can be saved with the insertion of variable speed drive to six pumps on Bleach plant 4 in Skutskär Mill. The work was performed with electrical measurements during one week, analysis of pump curves and the compilation of production data over a year.The results show that four of these six pumps were profitable and yielded an annual saving of 1172 MWh of electricity and 560 000 SEK. With an economic lifetime of 10 years and a discount rate of 6.8% the final result for the entire life-cycle savings became 3 355 000 SEK.

Norconsult AB has developed a solarhousing concept, a house designed for the warm climate in the Middle East andwith large quantities of solar panels installed. The cooling system for the house was designed in an earlier report, the purpose of this thesis is to investigate the possibility of short and long term storage of thermal energy via an underground energy storage volume.Two different designs of the storage and three different filling materials have been integrated into a model to simulate different cases. The first design consisted of pipes installed in the ground, without insulation. The second design consisted of an insulated concrete box installed to prevent thermal energy from the surrounding soil to flow towards the lower temperature regions within the storage. The three different filling materials were dry saudi sand, water saturated saudi sand and the filling material used by the client for energy storage in Sweden.The results from the simulations show that neither of the designs, regardless of the filling material, managed to extract enough thermal energy from the house to the ground to uphold the demands of indoor climate.

Food is widely consumed and in 2011 an average American devoured approximately one ton of food. The production of these goods requires large amounts of energy and contributes to 22-31 % of all greenhouse gas emissions occurring in Europe. More than one third of the produced food is discarded instead of consumed, and food waste make up about 30 % of the waste generated by households. 60 % of this food waste could be avoided if the eatables were handled in a better way.Avoidable food waste arises partly because residues from food are not taken care of, and because the food is not stored in a way that optimise its durability. Residues arises part- ly because of the contradictory and complex demands of everyday life and are, because of our busy lifestyle, difficult to avoid.

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.

This thesis consider alternatives for heating and cooling planned office buildings at Arlanda airport. The thesis is divided into three parts where the third part is a shorter synthesis of the two first. In the first part the energy demands of the buildings are modelled in a computer program. Two different building models are created, one more conventional and one with good energy properties. The results shows that with proper construction and ventilation systems etc.

Considering that the price and demand for energy gradually has risen over the past decade and a wider discussion about the human impact on the environment has become increasingly more important and given a clearer role in modern society. This has contributed to increased incentives to reduce the use of fossil fuels and increase the use of renewable energy.The agriculture currently accounts for 20 % of Sweden's total greenhouse gas emissions. A way for an agricultural company like Wapnö AB to reduce their emissions could be to utilize existing renewable energy sources within their own premises.The report's aim is to create an energy audit of Wapnö?s existing energy system and how it changes with a future biogas plant in operation. The energy audit is used to illustrate how the company?s climate footprint could change.

The purpose of this study is to understand the factors that are affecting students at the Technology and Electricity- and energy programs in their choice of studies and vocation. The study is a comparative case study and quantitative method has been used in the form of questionnaires. The result shows that students do not like to be affected by another person but believes that they themselves have made their choice. Interest turns out to be the biggest influence factor of choice for both students at the Technology and Electricity- and energy program. For Electricity- and energy students have also access to work had some impact.The parents' education level was higher for Technician students and their parents worked with occupations requiring university degrees.

In June 2006 the Swedish government decided that the use of energy in buildings should be reduced by 20 percent until 2020, compared to the level of energy used in 1995. To contribute to this goal, the real estate company ?Eskilstuna Kommunfastigheter AB?, set up own goals for their buildings. In 2009, the goal for schools was to have a maximum energy use of 118 kWh/m2year for heating and hot water.The school ?Hållsta skola?, just south of Eskilstuna, exceeds the limit since it used 270 kWh in 2008.

This report is the product of the course AF101X, a bachelors degree in Samhällsbyggnad atKTH. The task of the course is to design a small house at a given location and also implement adeepening study. The house in this report is located in Kiruna in the north of Sweden, where theclimate is much colder than in the rest of the country.The deepening study of this report is to evaluates how realistic passive housing north of thePolar Circle is based on those facts. The house will to some extent be designed to fit the passivehousing standard.

In today?s society a large focus is put on energy systems and how our energy systems are built up. In order to make sure that we in the future still can enjoy the living standards that we are used to today, Sweden and EU have made a number of decisions on making our energy system more energy efficient and consequently reduce the usage of energy resources. By 2020 the European Union should have reduced its energy consumption by 20 % compared to 1990?s level, and by 2050, 50%.

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.