Skärgårdsstiftelsen, which is responsible for several of the archipelago islands in Stockholm, has chosen to explore the possibilities for more sustainable heating systems in buildings on the islands in collaboration with KTH. A reduction of energy use and improving the efficiency of existing heating systems are included as part of the environmental work. This report studies the island of Grinda, which is located outside the area of Vaxholm in Stockholm. The study area consists of a guesthouse consisting of a restaurant as well as conference facilities and four neighboring cottages used for overnighting. The cottages now run solely on direct electricity, both for heating and hot water.

A district heating plant has the advantage that it can take advantage of the waste heat from industries and use of cheap fuels to produce heat. But for the long term is competitive requires that energy is also saved in district heating plants. One way to save energy in a district heating system is to increasing cooling to the return temperature. This leads to less power needed to drive the distribution pumps,  and that more energy could be extracted from the same amount of fuel by an improved flue gas condensation.In Karlskoga the return temperature into the district heating plant is high. They would therefore reduce the return temperature in order to extract more energy from the flue gases.

Heat is distributed to the district heating customers through pipes with water as a heat carrier. The district heating system is complex. To decide what is leakages from the district heating net versus what is the water consumption of the plant, is difficult. Therefore, the purpose of this master thesis is to establish a model where the district heating net?s leakages but also the water consumption of the plant can be followed daily. The project is performed at Vattenfall´s district heating power plant in Uppsala. Information is gathered through discussions, drawings of the plant and guided tours of the plant.

The main goal with this thesis report was to come up with ideas of how to make the use of energy more effective and thus save money for the company.First a survey was made to find out where and how the energy consumers were divided within the company. The results were then used in calculations to find out how much money that could be saved and how long it would take to get back the investments.There is a big potential in saving money by recovering heat from the UV-lamps with a heat exchanger. It would also even out the pressure in the factory which is a source to heat loss and a cause for discomfort amongst the employees. It?s possible to save 105 000 kr in a year and the money needed for the investments is 600 000 kr.By using the recovery air more effectively the company could save up to 250 000 kr a year in lowered heat purchases, but this would require the use of automatic dampers.If you reschedule the running times for the wood chipper and invest in some kind of load management, for example Sydkraft?s ?Energidirigent? you can save at least 42 000 kr.

People in today?s society are becoming more and more aware of how important it is to use energy as efficiently as possible. This is clearly noticeable by an increase in home produced heat with e.g. solar panels or heat pumps heating systems. These changing customer demands forces district heating technology to be redesigned, which is why there is an ongoing research regarding the next generation of district heating - low temperature district heating (LTDH).

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.

Sweden has long had access to low electricity prices due to the wide availability of hydro and nuclear power. This has now changed because of today's rising electricity rates resulting in increasing heating costs for properties, especially in the properties with electric heating systems."Ankaret" is a parish for "Svenska Alliansmissionen", which is located at "Gullbrannagården".The parish has installed electrical radiators and an exhaust ventilation system that makes the energy demand high due to the large ventilation flows. The building was built as the price of electricity was still low and would reduce energy use today by combining its heating system with an air/air heat pump. The heat pump delivers more heat into the room than the electrical energy that it uses. This lowers the electricity needs.

Cooling down the indoor air can be done in several ways. One way is desiccantcooling which will be used at the Stockholm Arena. This method is used in airhandling units that use temperature changes and moisture fluctuations in the air. Oneof the steps is to add heat during the cooling process in order to reduce the relativehumidity of the exhaust air. The air passes thru an adsorptions rotor which thenabsorbs moisture from the supply air.

The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.

A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?.

This report was performed in order to evaluate a new technological measure and focuses generally on a heat pump system to a HWC-washing machine. The client is Asko Appliances AB, a company well known for its environmentally friendly products. The goal of this study was to improve the energy efficiency of a washing machine by combining a heat pump device to the heater of the wash water, in order to reduce the energy consumed for heating the water. Besides reducing the energy consumption in heating the water, the washing machine was required to meet low noise and short operating time specifications. For that purpose, nine trials in three test series have been carried out.

Chapter 1 defines the aim of the project and gives a general orientation about ground heat extractors. In chapter 2 physical processes that could be expected to be involved in the heat transport around a ground heat exchanger are discussed. It is shown from a literature study what amount of moisture transport due to thermal gradients there could be expected in a ground heat exchanger. The conclusion is drawn that the moisture gradient (Sr) is of same magnitude as the driving temperature gradient (°C). At the expected amount of increased moisture around the pipes the moisture transport could be considered to have a little effect on the brine temperature.

A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?.

Increased resource efficiency in an energy system could result in large economic and environmental benefits. Tekniska verken i Linköping AB (Tekniska verken) is responsible for the district heating network in Linköping. Their vision is to create the world?s most resource efficient region. An important step towards this vision is more efficient usage of produced heat, something which could be achieved through integration of a seasonal heat storage in the energy system.

A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.