A Multicriteria Approach to Evaluate Solar Assisted District Heating in the German Market

Following the ambitious EU plan in cutting the greenhouse emission and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, seasonal storage coupled with district heating plants can have a viable contribution to this goal. However, the performance uncertainty combined with the inadequate assessment regarding the financial potential and the greenhouse emission reduction associated with the deployment of those innovate district heating systems represents a great challenge for sufficiently apply it. Our work tends to explore the prospects for wide-scale deployment of the seasonal storage in the residential sector in the German market. The proposed methodology framework correspondingly based on a multi-objective approach which is applied to optimize the cost against an aggregated environmental metric throughout the life cycle of the proposed system in comparison to their relative conventional heating systems. In this context, the proposed methodology framework is applied to Berlin as a representative for the central European climate zone with consideration for the seasonal and short-term storage systems and their relatively load profiles. The environmental improvement associated with the solar district heating system (SDHS) coupled with seasonal storage in the central European climate zone is heavily weighed enough in decision making for proposing SDHS as a sustainable solution replacing the conventional heat sources. Furthermore, the proposed methodology framework successes in eliminating the yearly system variation. Thus, the yearly solar fraction never goes down below than 97.8% in the investigated climate zone. Overall this study can assist in approving the feasibility of the SDHS with the goal of establishing a more sustainable energy infrastructure in Germany.