During 2007 the City of Stockholm installed five grid connected photovoltaic systems. The aim of this master thesis is to quantify the amount of produced energy and recommend routines to collect and analyse production data, to make production data accessible by the public and to gain experience for future installations.The total amount of produced energy until March 2009 is 227 000 kWh, with an annual rate of 150 000 kWh. The expected annual rate was 148 000 kWh.All system owners are positive about their plants and see economical benefits in scaling up such systems.The installations need very little attendance and maintenance, however it is recommended that an alarm function is installed for automatic feedback in case of a system failure. All future systems should be inspected during full operation to determine if the actual capacity is matching the installed capacity..

This report deals with RFID systems and how to detect nearby tags with the Mifare standard using only a microcontroller and an antenna circuit.The aim was to investigate whether there was any possibility to continuously search for a nearby tag for a system operated with batteries without compromising   the lifespan of the battery. At this time the system would take too long time to wake up and look for a tag to give a satisfactory battery lifespan, which should be done a couple of times every second.The report has two issues, namely:Is it possible to direct the microprocessor to detect and identify a nearby tag after the Mifare standard?What hardware is required for this to be possible?As the research method to provide answers to the above questions an action research was used. This approach has meant that the group worked on information retrieval, examined existing solutions, tested their own solutions and documented the results.The group examined an existing solution that can search for nearby tags with minimal Energy consumption. An antenna circuit was built that was connected to the processor.

I detta examensarbete studeras kommande energikrav för byggnader i Sverige och i synnerhet kraven påspecifik energianvändning. Detta mot bakgrund av EU-kommissionens och EU-parlamentets direktiv,EPBD2, om nära nollenergibyggnader 2020. Därefter bearbetas ett förslag på en nyytterväggskonstruktion som med lägre U-värde än den befintliga ytterväggen ska sänkaFiskarhedenvillans olika hustypers specifika energianvändning. Syftet med sänkningen är att möjliggöraför Fiskarhedenvillan att uppfylla de kommande energikraven.Det är många parametrar som måste uppfyllas och det nya ytterväggsförslaget analyseras förutom urenergisynpunkt även med hänsyn till statik, fukt och kostnad. Beräkningar för statik och specifikenergianvändning har gjorts för ett referenshus.Resultatet av att byta ut den befintliga ytterväggskonstruktionen mot det framarbetade förslaget medca 33 % lägre U-värde gav endast en sänkning med ca 6 % av den specifika energianvändningen.

The development of solar photovoltaic (PV) is increasing,with declining module prices and with a strongenvironmental profile. Policies are developed around theworld to achieve the targets set for renewable energy.In Helsingborg, the local power company Öresundskraft isworking with solar PV to achieve the goals of the city.With their vision: - Energy for a Better World and Powerfor the Region, their work with developing the local solarPV market is continuing and the next step is to create asolar PV policy. Today their offer is 1 SEK/kWh for theexcess electricity delivered to the grid.It turns out that compensating the customer is a vitalpolicy and it has to be dynamic to follow the decisions ofpolitics. The same survey shows indeed, thatenvironmental and technical part is of interest. Solar PVwill be supported locally to act on environmentalsustainability and locally produced electricity and withthis Öresundskrafts vision will be achieved..

During the last decades the housing sector has increased continuously, and housings and services accounted for 40 % of the energy usage in Sweden during 2011. The expansion in number of buildings in society has resulted in an increase in both energy usage and emissions of greenhouse gases. It is crucial to enable a sustainable development of society and as a result, the demand to reduce the emissions of carbon dioxide is a current question. In this study, the carbon dioxide emitted from the housing sector in Stockholm is estimated. The housing sector can be divided into different types of houses such as apartment blocks, single-family houses and holiday houses. By collecting information of the energy purchased in respective households, a computational model is generated that calculates the total emission of carbon dioxide.

Feed intake in dairy cows is regulated by a variety of factors influencing hunger and satiety. One of the regulation systems includes the short chain fatty acids produced during feed degradation in the rumen. Starch can be digested either in the rumen where short chain fatty acids are produced or in the small intestine where glucose is the end product. Since glucose does not have the same effect on satiety that short chain fatty acids have, the site of starch digestion might be an important factor that affects feed intake and milk production. The aim of this study was to investigate the effects of site of starch digestion on feeding behaviour (feed intake, consumption time, and eating frequency) and milk production. Because feeding behaviour is closely connected to the cows? environment, the study also included observations of behaviour. Three different feed rations were compared.

The purpose of this master thesis was to study the water system for mechanically cleaned water at Skärblacka mill, in order to find and evaluate possibilities of using energy more efficiently. The thesis also includes an evaluation of the software tool ?Pumpanalys?Skärblacka mill produces pulp and paper. The large amount of water required is cleaned mechanically through filters and called mechanically cleaned water (MR0). The MR0 water is pumped out to the factory by four crude water pumps.

The coproduct, dried distillers grains + solubles (DDGS) from ethanol production based on wheat contains much rumen degradable protein and fiber with low digestibility. To compliment this quality in an effective way a grass silage low in protein and much digestible fiber is needed. The aim of the study was to investigate the effects of adjusting the crude-protein concentration and fiber quality of the silage when feeding DDGS and of varying the inclusion level of DDGS, when feeding the adjusted grass silage, on intake, milk yield and composition, faecal traits and feed efficiency. Four different total mixed rations were compared. The normal grass-clover silage had a crude protein content of 17,8 % and an NDF content of 46,2 % of dry matter. The adapted grass silage had a crude protein content of 14,6 % and an NDF content of 52,9 % of dry matter. The diets were formulated to have similar nutritional content except for A + 4 which had a higher content of rumen degradable crude protein and a lower concentration of NDF.

Emissions of insufficiently treated wastewater, mainly blackwater (i.e. wastewater from toilets), contributes to the eutrophication of lakes and seas. At the same time, blackwater is a fraction with a low content of heavy metals and, after sanitization, it can recirculate plant nutrients to arable land using the liquid composting treatment method. Liquid composting means that organic material is degraded under aerobic conditions. For sanitization, the blackwater needs to be treated together with energy-rich complementary material.

The Rya power plant in Borås produces district heating, district cooling and electricity. The plant is owned by Borås Energi och Miljö AB and is run by Dalkia Facility Management AB.In order to get the best heat exchange from the district hot water a pair of twin pumps and a turbine circuit pump are used as return pumps. Turbine circuit pumps are used to increase the pressure through the heat exchangers at the power plant. The pumps are in use when the flow is over 2 000 m3 h-1 and during the summer when re-cooling is used to improve the effectivens of the heat boilers.Since the pumps, that are parallel connected, rotating at a fixed rate per minute, the pressure is regulated with regulating valves. This report shows that during the 4,300 hours that the pumps where in use, energy corresponding to 590 MWh was wasted.

Stump biomass is energy rich and stump harvesting for use as fuel become more and more interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump harvesting in Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of stump are probably of great importance to make it accepted as fuel. It is therefore rewarding to carry out an investigation in this area for stump. This report represents results from a diploma project, which was aimed to develop a fixed bed reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic modelling employing Ozawa method and different kinetic models including one-step and three-pseudo-component models.

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 use of streaming media such as Spotify has increased rapidly in recent years. Although the consumption side of Spotify is well established with over 10 million users, the medium might provide new unexploited opportunities as an advertising channel. The purpose of this thesis is to increase knowledge about advertising through streaming media and in particular via Spotify. To contribute to such knowledge we have conducted a case study to investigate how Spotify can be used and serve as an advertising medium for a smaller firm, Hasseludden Yasuragi, so that it may reach its target group. To examine the medial effect, a quantitative as well as a qualitative study was carried out using the ARF Model as a basic framework.

The purpose of this thesis is to investigate the possibility to make small, cheap and ultra low power sensor platforms, connected in wireless networks for monitoring of home and industrial environments. The concept is based on ideas from our supervisor, Jerry Lindblom. The developed system consists of a generic platform for different sensors, a receiver and software. A GPRS module from RO Rollytech AB and a database from Gema Industri AB have been modified and used to demonstrate an example of a complete system. To the platform, it is possible to connect any resistive sensor and any sensor that can act as a switch.

This essay includes the planning and designing of a house as well as writing a rapport about howto increase fire safety in small buildings.More than 6000 homes burn in Sweden every year (Brandskyddsföreningen, 2012c). Thedevastation and the costs are usually very high. This report examines possible measures to reduceboth personal injuries and economic losses resulting from house fires in small buildings.Swedishbuilding regulationsplay a major role when it comes to constructional fire safety. However therequirements inSwedish building regulations are very low for small buildings and this is anargument for raising the requirements.The report shows and describes possible methods to build safer with regards to fire in terms ofmaterials and different building structures. Major focus has been on fire cells but other solutionsare also examined and described.