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.

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.

An increasing number of heat pump producers have developed heat pumps that can be connected to solar panels. In this thesis we have examined the possibilities of connecting solar panels to existing ground source- and geothermal heat pumps that has not been adapted to solar panels. During the work process, a prototype plant has been built to compare our theory with the practical results and with our designed sizing tool. The work has rendered in knowledge that will be used to build a sun module that can be easily connect to the existing heat pump system. The existing heat pump, our test plant, has been supplemented by an advanced storage tank used to allow different operating modes.

Modern technology and fast development of heat pumps, the hunt for savings in energy consumption and the strive for environmentally friendly energy sources, convenience, and financial profit, have made heat pumps a reasonable alternative for the heating of houses.When the heat pump starts it will consume a considerable amount of current, which may result in a short-lived voltage-drop if the power grid is weak compared to the start-up current.The company Fortum Distribution which owns and administrates electrical network is interested in an investigation that deals with heat pumps affect on the quality of electricity.The purpose of this investigation is to study fast electrical fluctuations (flicker) as a result of start-up currents for single as well as multiple heat pumps on the same electrical station and from this evaluate whether there will be any problems installing heat pumps..

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.

This diploma work covers an investigation over the heat - and hot water systems of thetenant-owner's association, Bogården. The heat - and hot water needs of Bogården aresatisfied by both district heating as well as three heat pumps. Implemented investigationshows that the heat pumps are not used in a profitable way. Apart from that, the reservepossibilities are small. There is also a risk of the growth of Legionella bacterium in thehot water system.Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården)has a wish to investigate possible proposed actions for optimization of existing plant.After completed investigation, a new proposed action is presented.

Finnhamn is a group of islands that are located in the middle north part of Stockholm?s archipelagos. On the main island Stora Jolpan there is a camp called Sommargården, which consists of eleven different buildings in various sizes. The assignment given by the Archipelago foundation (Skärgårdsstiftelsen) is to analyze if it?s benefited to replace Sommargårdens current heating system that consists of electricity radiators, with a more energy efficient heating system. This research is done with help of the literature review and a visit to Finnhamn in order to map Sommargården?s current state and its energy usage.

If a building is heated by a heat pump, it is of high importance that the heat pump has a high coefficient of performance. An exhaust air heat pump extracts heat from the building?s exhaust air. The air has a relatively high and constant temperature all year around, leading to a high seasonal coefficient of performance. This thesis examines whether it is profitable to complement an exhaust ventilation system with an exhaust air heat pump in an apartment block that already has geothermal heat pump, district heating, oil- or biofuel heated system.

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.

Vattenfall district Heating power plant in Uppsala produces district cooling with absorption heat pumps which leads to a large amount of waste heat that has to be cooled with evaporative cooling towers. The Environmental Court has ordered Vattenfall to survey the possibilities to recover the heat, which is the focus of this thesis.The study begins with an overview of the system, and conditions and limitations for waste heat recovery is examined. In the next step alternatives to recycle the heat is evaluated, either by direct recovering or by upgrading.First, the technical possibility of each alternative is discussed, and then the operation time and the amount of recovered heat is calculated. Those alternatives which are possible are brought further to an economic analysis.The cost of investment for each alternative constitutes the basis for a present value analysis. The results are put together in a table where the total amount of recovered heat is compared with the present value for the different alternatives.

Gunsta is situated about 10 km east of Uppsala. Today there are plans to establish 1000 new households in Gunsta before year 2030. The required energy for heating houses and water would be distributed via a district heating system, which also includes 200 existing residences. The annual required energy, according to this study, would be 16.2 GWh with a maximal peak effect of 6.9 MW. To meet this need, the study suggests a system with heat pumps to upgrade the 31?C water from a 1.8 kilometre deep borehole.

The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat exchangers. For this reason, the annular coaxial borehole heat exchanger (CBHE) has been analyzed. This type of heat exchanger is interesting in terms of both thermal and hydrodynamic performance. A model has been set up in the program Comsol Multiphysics in order to investigate the heat transfer characteristics along the borehole.

The thermal response of a borehole field is often described by non?dimensional response factors called gfunctions.The g?function was firstly generated as a numerical solution based on SBM (Superposition BoreholeModel). An analytical approach, the FLS (Finite Line Source), is also accepted for generating the g?function. In thiswork the potential to numerically produce g?functions is studied for circular borehole fields using the commercialsoftware COMSOL.

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?.

Sweden?s energy consumption is divided into three major sectors. One of them is the industry sector. One third of Sweden?s energy consumption is converted in the industries.