Biogas is an expanding sector within the broad field of agriculture and animal production. Small-scale biogas offers local combined power and heating production and the substrate is transformed into high-quality biological fertilizer. This bachelor thesis focuses on a pig farm in south-western Sweden, where biogas is produced from pig manure, evaluates and suggests ways of optimizing the process and investigates whether investing in an upgrading plant would be a feasible and more cost-efficient option. The results show that the biogas plant is working well, although the production differs from the original plans. This shows in turn that planning and examining the basic conditions before making the investment is of great importance, as well as monitoring and keeping detailed statistics of the running process.

Our purpose in this paper is to examine if there is any profitability for a company with a factory in the timber industry to invest in a combined heat and power, CHP. Based on analysis and the results that the paper generates, we will give Derome AB a suggestion on how it is a profitable investment or not to installing in a CHP.By investing in a CHP plant, you can get a high efficiency, which means that companies can use their resources more effectively. The Swedish wood industry has by-products of production that can be used for combustion in their boiler which is an advantage.The essay is a qualitative study where we have a case company, Derome AB. In this company, we interviewed two employees who have knowledge in the study. They have helped us to provide information and data about their business.We chose to use the pay-off- and the net present value method, NPV, to see if there are profitable advantages for the investment.

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 thesis has identified and studied measures to allow for reduced use of electricity in a waste incineration plant in western Sweden. The energy extracted from the waste at the powerplant is utilized and sold in form of electricity and heat. Technical and environmentally the combined heat and power plant is by today's standards among the leading waste incineration plants in the world. The owners are constantly striving to improve the efficiency of the waste incineration plant. They have seen the opportunities for savings in reducing internal usage of electricity.

Energy efficiency is important both to reduce costs and to reduce greenhouse gas in the atmosphere. In Sweden 40 percent of the energy consumption is related to the buildings sector. Hospitals are complex buildings with different activities in the same building, which requires flexible technical systems for ventilation, heating and lightning. A quarter of the total energy consumption in Swedish hospitals is related to user activities in the hospitals. Therefore it is not only important to work with operational optimization but also to change user activities, to reduce energy consumption.The objective of this thesis was to examine the user-related energy efficiency work at two care units, at the central hospital in Sundsvall within Västernorrlands County.

With increasing energy prices and increased focus on the environment we saw the need for companies to get control over their energy use and their emission of carbon dioxid. An analysis tool that integrates both these areas is, with our knowledge, not available on the market today. Therefore, our project became to develop such a tool.By doing this degree project we would like to clarify that energy consumption and environmental impact are integrated. The less energy consumed by today?s society the smaller the environmental impact will be.

Food waste from grocery stores - An analysis of municipal management inSweden and a detailed study of the situation in Umeå municipalityThe objective of this thesis was to analyze the municipal management of food waste fromgrocery stores in Sweden in general and in Umeå municipality in particular. Furthermore theobjective was to account for the different waste treatment methods that can be used and toevaluate them from an environmental perspective. In order to analyze the municipalmanagement a survey was sent to all of the municipalities/municipal waste companies inSweden. A general comparison of treatment methods was carried out on the basis of ascientific review and a system analysis was performed in order to compare three differenttreatment alternatives for the food waste generated in grocery stores in Umeå. The surveyshowed that the legal definition of food waste from grocery stores is unclear and variesbetween municipalities.

Detta examensarbete på 15 högskolepoäng har som syfte att undersöka några åtgärder för minskade uppvärmningskostnader. Då det byggs mycket nytt idag får man inte glömma bort alla befintliga byggnader. Det första steget mot minskad energianvändning är att minimera uppvärmningsbehovet. I detta arbete har vissa utvalda åtgärder beräknats på en 70-tals villa för att se vad man sparar in. Genom mätningar och information från villans byggnadsbeskrivning beräknas byggnadsdelarnas U-värden.

Biogas mainly consists of methane and carbon dioxide, where methane is theenergy-rich gas, and is naturally created when organic matter breaks down in absenceof oxygen, also known as anaerobic digestion. A biogas plant re-creates the anaerobicconditions inside a digester where the organic substrate is fed into and digests toproduce biogas. The gas is then used to produce energy by combustion and can beseen as a completely renewable fuel.Today, energy from biogas is used primarily by major stakeholders such asmunicipalities and thus the plants become very large with high investment- andconstruction costs. There are currently few small plants in Sweden, even though thepotential for agriculture and medium-sized to smaller farms to become self-sufficientin terms of electricity and heat is great. Farms have a natural stock of digestibleorganic material in form of manure or crops for example, which are constantlyavailable.

Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project.  These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.

In recent years the construction industry has been exposed to increased time pressure which has resulted in a higher amount of wastage. Today 35 % of all construction projects in Sweden is "wasted". Time pressure has risen due to increased competition on the market, with more actors entering the construction business, therefore profit margins decreased which has led to a more pressing need for decreasing the amount of wastage.Bravida is Scandinavia's largest supplier of installations and provides specialist services in electrical installations (heating and sanitation), and ventilation. Mahdi Bawaqneh's task was to investigate where, how and why wastage occurs in the company's projects and how to prevent such wastage. The thesis covers the subjects of lean production, communication in projects and planning of projects.

Stump wood is a hot alternative when the heating plants demands more and more forest fuel. The aim with the study has bean to calculate the costs in four different systems for transportations of stump wood, examine if there are any differences in fuel quality for the stump wood in the different systems, analyse if the fuel quality in stump wood is affected with the time it lays by the road side and how much space the stump wood demands on the road side. To calculate the costs for the different systems a system analysis was carried out, where some of the costs were collected through field studies on Holmen Skog stump experiment and other costs were collected from literature and contacts. Data for the fuel quality study was collected from Eons heat plant in Norrköping. Data for the study of how much space stump wood takes along a roadside was collected from field studies.

The division of Engineering Materials at Linköping University, department of Management and Engineering, conducted a research project concerning Fatigue life of thermal barrier coatings during 2009. During this project equipment to provoke these fatigue failure by rapidly heating and cooling test subjects in cycles, was ordered.Design and manufacturing of the equipment was handled internally at LIU.The equipment was built using a furnace that is lowered and raised over the table where the test subject is placed. To keep the temperature of the furnace a lid slides in place to close the downward facing opening of the furnace when it is in the raised position. On this door there is nozzle that is used to cooling of the test subject by air.To make sure that the equipment can work independently you need an automation controller that can evaluate if movement can occur without danger of collisions. The control system also needs to monitor that all elements are performed according to plan.This degree project is based on a modular system from OPTO 22 and includes the configuration of a PLC that will be supplied with logic and a user interface.The degree project resulted in a graphic interface in which a user can set desired values for different parameters and get information about current values for them.

The energy that the earth receives from the sun hourly has potential to cover a year?s energy demand in the world. Further, this type of energy is environmentally friendly, natural and free of cost. This report covers solar energy in an urban environment and consists of a case study of installations of photovoltaic cells in a part of the city of Stockholm. It is mainly the economic aspects that are covered but there is also a discussion about the practical consequences and the sustainability as a result of integration of solar energy in an urban environment. The aim of the study is to present results from economic calculations for utilization of solar energy in chosen buildings in Kungsholmen in Stockholm.

The number of people in the world and the urbanization increases. This leads to a bigger need of space for the built environment, space that soon doesn?t exist. A large portion of humanity?s energy disposal is used for heating of buildings.