Reducing carbon emissions in our societies requires a massive shift towards renewables. In Sweden, biomass is the dominant source for the district heat production, but growing demand for biomass in other sectors may cause pressure on it. In this context, this thesis explores the possibility to supply heat with solar parabolic thermal collectors to a district heating system in Kosta, a locality in Lessebo municipality, Kronoberg county. The simulations and calculations are based on the locally available hourly data of weather conditions, supply and return temperatures of district heat and heat demand profiles. The energy production as well as the profitability of the installation is evaluated through the calculation of carbon abatement costs, considering that heat supplied from solar collectors spares biomass which can be made available for decarbonating the power sector. Results have shown that a solar installation that cover most of the heat demand during the months of summer, thus 10% of the annual heat demand, can be profitable. This study also investigates different scenarios with increased costs for the biomass resource to simulate the growing pressure around this resource and concludes that with growing costs of the biomass resource, solar application will become more attractive, allowing to make larger solar district heating plants profitable.

This master thesis deals with the influence of glazing on the microclimate inside buildings. In particular, I focused on the shading coefficient and the various factors that affect it. The thesis also concentrates on the origin and composition of the solar radiation, the formation of thermal stress and refraction. In the next part of the thesis, I focused on designing two variants of shielding factor and its impact on the thermal load of gym, sports hall and the related necessary changes. The last part of the thesis deals with experimental measurements of incident solar radiation passing through the window into real physical model. From the measured values, we determined realistic shading coefficient and then applied it in the previous section of this thesis.

The master´s thesis analyzes influence of direct and reflected solar radiation to heat strain and degradation of thermal insulation in the flat roof construction. In many building was a problem in a significant degradation of thermal insulation made from expanded polystyrene in the vicinity of glass surfaces. To determine the causes of this problem, it was necessary to study and test the properties of building materials and the physical nature of the effect of solar radiation on the building structure. In the introductory section lists the cases of buildings with degradation of thermal insulation and existing knowledge on this issue. The theoretical part describes the technical properties of thermal insulating materials used in the flat roof construction, nature and division of solar radiation, optical laws of light reflection and physical theory to explain the technical thermal behavior of building materials and structures. The last part describes a practical model and analyzing measured data in thermal stress in the flat roof construction. The practical part also determines the importance of different influences configuration structures using to dynamic simulations. At the end of the practical part they are validated theoretical knowledge obtained by analyzing data from a practical model.