The sun is essential to life on earth and no matter where you are, there is a constant need ofenergy. Nearly 800 000 years ago man learned for the first time to use fire in a controlled way.Since then, fire has given us the opportunity to inhabit places despite a cold climate. In Swedenthe resident sector accounts for a major part of the total consumption of energy. In a time whenenvironmental issues and greenhouse effects are increasing, we also see a future of rising energyprices. With this perspective, we have in this bachelor thesis in the Building Environment at theRoyal Institute of Technology, KTH, in Stockholm decided to focus on the renewable energysource, solar energy.The energy from solar radiation is a free resource and does not have any negative effects uponthe environment.

Humanity stands before a huge challenge to lower its emissions of carbon dioxide and its use of energy at the same time as the global population is rising and the developing countries are being industrialized. A lot of newly built buildings are due to this challenge, designed to be more energy efficient but also use renewable energy resources instead of pollutant fossil fuels .Solar energy is one of the purest forms of energy that exists in abundant amounts, which is why it is most likely that it could come to play a major part in the future energy market. The main purpose of this report is to investigate the possibility to implement a sustainable energy system with solar thermal heat and  heat storage as main sources of energy in the neighborhood ?kvarteret Lagern?, which is the area where the old football stadium ?Rasunda Stadion? was located. New developments within different heat storage techniques have opened up new approaches to enable buildings an all year round heat supply from solar energy. This report will focus on heat storage in boreholes. At the present here is only a preliminary plan of how the neighborhood is supposed to be designed.

The housing sector uses 40 % of the energy in Sweden and half of the electricity usage. Theuse of energy is the main reason to the increasing rate of carbon dioxide in the atmosphere.This is the main motive but also a wish of higher safety, that is a higher rate of selfsufficientenergy production in Sweden, we want to decrease the need of using fossil fuel. Now whenthe energy price rise, the interest in energy issues increase and more people discuss thepossibility of reducing the usage of fossil fuel. A change to renewable energy such as sun,wind and water is the only solution where we can get a sustainable development.One way to contribute to a better use of energy is to build in the principle of passive house.The house is being built with a thick and tight insulation. If you use a heat-exchanger withhigh degree of efficiency and a final heating battery on the ventilation system, the heat fromlamps, devices and the ones living in the house should be enough to fulfil the criteria ofliving.

In recent years it has become more and more evident that man has contributed to much of the climate changes that have taken place during the last century. A major challenge today is to reduce emissions and energy usage at the same time as the global population is growing. To contribute to a better environment, Stockholms Stad has set at target of becoming fossil fuel free by the year of 2050. The construction of new districts is done with this goal in mind; energy efficiency and renewable energy sources are examples of methods to achieve this.Solar energy is considered to be a sustainable energy source and the most common techniques to harvest solar energy in Sweden are solar cells and solar Collectors which produce electricity and heat respectively. This report aims to investigate whether an investment in any of these systems would prove to be economically beneficial at Kvarnholmen, a district under construction in eastern Nacka, Stockholm.Since the finished blueprints only cover a small portion of Kvarnholmen, the report examines the possibilities for a house where construction has already begun, Nya Kvarnen.

This report treats whether it is viable to invest in solar heating to heat the therapy pool at Östersunds Rehabcentrum. The rehab center is owned by the county council of Jämtland and is located on Solliden in Östersund city. The solar heating where supposed to be a complement to the district heating that was heating the pool in the current situation. Later, it however showed that this was not the case. The pool is currently being heated by a radiator circuit that is being heated by the district heating.

The district heating load is seasonally dependent, with a low load during periods of high ambient temperature. Thermal energy storage (TES) has the potential to shift heating loads from winter to summer, thus reducing cost and environmental impact of District Heat production. In this study, a concept of high temperature borehole thermal energy storage (HT-BTES) together with a pellet heating plant for temperature boost, is presented and evaluated by its technical limitations, its ability to supply heat, its function within the district heating system, as well as its environmental impact and economic viability in Gothenburg, Sweden, a city with access to high quantities of waste heat.The concept has proven potentially environmentally friendly and potentially profitable if its design is balanced to achieve a good enough supply temperature from the HT-BTES. The size of the heat storage, the distance between boreholes and low borehole thermal resistance are key parameters to achieve high temperature. Profitability increases if a location with lower temperature demand, as well as risk of future shortage of supply, can be met.