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.

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.

The purpose of this study was to investigate the association between physical activity and perceived stress, energy and musculoskeletal disorders among office-workers and warehouse-workers and also to see if there were any differences depending on work-place and gender. The method that was used to collect data was three different validated questionnaires that measured stress and energy (the Stress-Energy questionnaire), musculoskeletal disorders (intensity and localization of pain, a Pain Drawing questionnaire with a VAS-scale) and physical activity (IPAQ ? the short version). Eighty-eight workers participated in the study. Forty-seven of them were office-workers and forty-one were warehouse-workers.

This project investigated the current market regarding wireless net and the communication between the tools used for diagnostics/maintenance and an embedded system. Based on documentation obtained through interviews a demo system was created based on Bluetooth Low Energy (BLE) communication between an embedded system and an Android device.This report intends to describe the tools and methods used in the design of the demo system and the result of an analysis of the BLE communication.Bluetooth Low Energy is an exciting protocol with wide applicability within the industrial field. This project investigated the communicational possibilities between a Smartphone and a Raspberry Pi and based on the results that emerged the conclusion can be drawn that BLE is a protocol with many beneficial applications within industrial IT..

The purpose of this master thesis is to investigate how nearby forests affect the energy production in wind turbines. To reach the purpose a case study is performed on three wind turbines sited on a field in a north-south line at Andersfält in the municipality of Halmstad, Sweden. Approximately 100 meters south of the southern wind turbine a forest is situated. The case study is divided into three sub studies where the difference in energy production, the affect of the forest and a wind meteorology model, WAsP, is studied. The result show that the forest have a significant influence and that the WAsP-model gives an incorrect result of the energy production in wind turbines sited near a forest..

På uppdrag av Sweco Systems i Umeå har detta examensarbete utförts under våren 2013. Syftet var att undersöka huruvida något av de energiberäknings-program som används på företaget kan anses vara lämpligt vid energikartläggningar av befintliga fastigheter.Inledningsvis utfördes en energikartläggning av fastigheten Odin 12 i Umeå, som i huvudsak utgörs av gallerian MVG. Med resultaten från denna energikartläggning som grund beräknades därefter fastighetens energianvändning i två olika program ? VIP-Energy och IDA Indoor Climate and Energy.Resultaten från den inledande kartläggningen visar att fastigheten har ett lågt behov av fjärrvärme, vilket förklaras av fastighetens höga elförbrukning. Den stora användningen av el genererar stora mängder internvärme som, förutom att sänka fjärrvärmebehovet, även medför att fastigheten under hela året har ett kylbehov.Utvärderingen av de två beräkningsprogrammen visar att VIP-Energy är ett lämpligt program att använda vid energikartläggningar.

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 study concerns the energy future of the county of Stockholm up until 2050 and describes how the energy consumption can be compared to today with the use of scenario methodology. Within energy future studies the backcasting approach is well known and has been put to use in this study. Due to the characteristics of backcasting the study is self-fulfilling, i.e. the future energy scenarios presented in this study satisfy the targets set up in this study. In the light of what may be the largest challenge of our time ? the climate change - the aim of this study is to describe how the energy consumption in a fossil fuel free Stockholm county in the year of 2050 may be.

The purpose of this study was to investigate the association between physical activity and perceived stress, energy and musculoskeletal disorders among office-workers and warehouse-workers and also to see if there were any differences depending on work-place and gender. The method that was used to collect data was three different validated questionnaires that measured stress and energy (the Stress-Energy questionnaire), musculoskeletal disorders (intensity and localization of pain, a Pain Drawing questionnaire with a VAS-scale) and physical activity (IPAQ ? the short version). Eighty-eight workers participated in the study. Forty-seven of them were office-workers and forty-one were warehouse-workers.

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.

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.

This study has examined if importation of waste for energy recovery can reduce the climate impacts of Waste Management Systems. Using Systems Analysis this study will try to examine the complex waste systems in a systematical and strictly logical way to see how these systems interact and affect each other. Specifically examining the climate impact of waste management systems in England. The traditional way of handling waste in England is through Landfills. Land filling leads to emissions of the greenhouse gas Methane. The EU has put in place a landfill directive that is supposed to lead the member states away from land filling as a method of waste management. Today in Sweden there is a competition for the waste available for incineration. The worsening economical situation together with less product packaging and an increase in source separation leads to a lack of waste available for incineration.

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.