As a part of Fortum's vision of a future Solar Economy, a feasibility study of a Solar District Heating facility was conducted. The focus of this study was to determine the technical, economic and environmental potential of a Solar District Heating facility, combined with a seasonal thermal storage, in the district heating network in Stockholm. Three different cases have been studied. The cases differ on the size of the available land area, on what type of storage technology utilized and if excess heat from different production facilities in the network is included or not. The results indicate that it is technically possible to implement a Solar District Heating facility in Stockholm, no obvious limitations in the network has been identified. The thermal storage should preferably be charged throughout the year and be discharged during December to March. The economic results indicate that none of the studied cases are economically feasible without any subsidies, increased revenues or other reductions of initial investment costs. The most economically beneficial system configuration was to utilize a smaller land area for solar collector installations, include excess heat from local production facilities and to utilize existing rock caverns and infrastructure in the area. The Solar District Heating facility could decrease the climate impact and the net primary energy use compared to the production of a biofuel production facility, but a further study is needed.