The City of Stockholm has decided to invest in renewable energy and especially in photovoltaics. The objective of this thesis is to investigate the photovoltaic potential on roof areas that the city possesses and to further investigate some buildings of the Property Management Department. The thesis also compares some existing photovoltaic plants with the solar irradiance map which shows available roof area on each building in Stockholm. The report ends with a literature study about the climate impact and greenhouse gas emissions of photovoltaic.The total available roof area suitable for photovoltaic plants is estimated to 700 000 m2, with a potential electricity production of 110 GWh per year. This corresponds to 17 % of the City of Stockholm?s yearly electricity consumption.

The European Council agreed in 2008 on a climate and energy package to combat global warming. This package is valid for each EU member country and means that greenhouse gas emissions must fall by at least 20% and the EU's energy use to 20%, consisting of Renewable Energy in 2020. The Swedish Government has set stringent climate and energy with the intention to set an example for the rest of Europe. For example, renewable energy sources account for at least 50% of energy use and our climate emissions to fall by 40% by 2020. A combination of these goals and a steadily rising oil price has led to an increased demand for wood fuel in the form of such branches and tops.

Road transports stand for a great part of Sweden?s total CO2-emissions. Transports are expected to increase over the coming years, and with those the emissions. A greater environmental awareness leads to increased demands for environmentally friendly transport. The aim of this thesis is to study the consequences of changing transportation modes from road to railway.

Global warming is a huge issue that humans have contributed to through over-exploitation of natural resources and extensive usage of fossil fuels. Now more than ever, we need to embrace a recycle thinking and reuse our waste, for example through producing biogas from our food waste. The purpose of this report was therefore to identify the energy usage and emissions resulting from the biogas chain which spans from Solna Stad to Uppsala Vatten. Furthermore, potential efficiency improvements were to be identified and proposed. This report focused mainly on the first part of the biogas chain that includes the collection of the food waste and the reloading process.

AbstractElectricity consumption is a globally increasing problem caused by the high share of electricity produced in coal power plants. These contribute to high carbon emissions when only about 1/3 of the heat generate electricity and the remaining 2/3 of the heat cools off. Combined heat and power plants (CHP) have high efficiency because they use the residual heat for domestic heating. The CHP plant often use fuels from renewable resources, giving them a lower carbon footprint, but are also depending on the heat demand. If electric powered products such as drying cabinets convert to heat powered products more environmentally friendly electricity will be produced by CHP plants, which can supplant electricity, produced from coal power plants and reduce carbon emissions.

Green public procurement (GPP) can be used as an instrument to reduce carbon dioxide emissions, and consideration of environmental aspects within public procurement is becoming more common in Sweden and internationally. Two product groups that have been pointed out as especially important are transports and electricity, where the opportunities for public purchasers to reduce emissions are relatively large. This paper studies GPP which aims at reducing emissions, primarily of carbon dioxide, through environmental requirements within these two product groups. A theoretical analysis of cost-effectiveness, transaction costs and effects on technological development is performed, followed by a closer study of how these aspects appear in practice within GPP. The results indicate that a cost-effective allocation of reductions between the two product groups is most likely to be attained if the main part of emission reduction is achieved through environmental requirements on electricity. The cost for emission reduction within transports is relatively high, especially for heavy transports. For transportation services, more generally focused requirements on emission reductions could probably give greater environmental gains, but the existence of transaction costs steer the environmental requirements towards more technology specific types.

Energy consumption is at present a major political issue, and numerous projects that comprise many nations are currently in process to increase energy efficiency and bring down energy dependency. As a member state of the EU, Sweden now faces the challenge of implementing substantial energy-saving measures until the year 2016. One of these measures is the project ?Green Islands? financed by the EU that intend on creating sustainable islands in areas around the Baltic Sea. The Archipelago Foundation leads the project that concerns the Stockholm archipelago, where focus has been placed upon decreasing energy usage in businesses and services on Utö among other islands.

This study deals with the technical and economic feasibility of replacing the nuclear power plant reactor Ringhals 3 with a biofuel power plant. A technical investigation has been executed to determine which of the systems and components that could be reused and which ones would need to be replaced. The investment costs of the reconstruction have also been estimated. The cost of the electricity production has been calculated as well as the emissions of the new biofuel power plant. Based on the established rate of return, the lowest average spot price of electricity that makes the investment profitable has been calculated.

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 costs constitute a large part of the expenses of dairy farmers. Pasture is a high quality feed with a low cost. However, feeding with concentrates has been shown to enhance milk yield (Leaver, 1985; Bargo et al., 2003; Stockdale, 2004). The purpose with this study was to investigate how milk yield and milk composition were affected as the concentrate proportion in the diet decreased. Pasture behaviour was examined to see if the different concentrate levels affected the time cows spent grazing and ruminating.

Food consumption generates externalities such as carbon dioxide emissions, which contribute to global warming. The principal issue is that emissions are not covered by the "polluter pays principle". For this reason, new policy instruments need to be tested and implemented to correct the externalities. In food production, beef and dairy production has the largest environmental impact in terms of carbon emissions. As food is a necessity, simply reducing production will not solve the problem.

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.

Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.

When grains of wheat and rye are conventionally milled, large quantities of bran classified as by-products are left and are mainly used for animal feed. Bran is a complex material composed of the aleurone layer, nucellar epidermis, a seed coat, a fruit coat and a small proportion of the germ and endosperm depending on extraction rate. The bran fraction consists of approximately 40-50 % dietary fibre which can contribute to increase the nutritional quality of human cereal food. It would also be valuable for the food industry to convert by-products as bran to products with higher commercial values. The aim of this thesis was to analyse the content and composition of dietary fibre of heat treated wheat and rye bran according to the Uppsala method with some modifications in order to analyse soluble and insoluble dietary fibre separately. Half of the bran samples were precooked, dried and roasted and the other half dried and roasted (uncooked).

The purpose of this study is to create a method that can be used to produce decisionsupport data for the climate goals of a municipality. The method should be able to demonstrate the potential for reducing energy use and greenhouse gas emissions for measures aimed at the stationary energy system in the municipality. It will be used to make longterm projections of energy use and greenhouse gas emissions in order to be able to demonstrate the ability to reach climate goals. The aim was also to test the method's applicability by using the municipality of Uppsala and the Uppsala climate protocol project in a case study. Uppsala climate protocol is a project consisting of participants from business, government and organizations that voluntarily want to commit to reducing their carbon footprint by reducing their energy use and thus work to achieve the municipality's overall climate goal. Public reporting of energy use and climate impact has been studied in order to examine the nature of indicators and accounting figures that are commonly used in the field and how long-term forecasts are formulated. In connection to this, the type and sources for the kind of data needed was also examined.