Effects of solar parabolic- trough collectors in small- scale district heating systems

Abstract: 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.