Benefits of Integrating Geographically Distributed District Heating Systems

Although liberalization of the electricity day-ahead markets has gained pace throughout the Europe, district heating markets are often dominated by lack of competition between suppliers, which curbs the potential of having cheaper systems in terms of socio-economic costs, and technically better system in terms of CO2 emissions. In order to assess the financial and technical outcome of connecting five adjacent district heating systems, a linear continuous optimization model that minimizes total socio-economic costs was developed. Geographical distribution of different district heating systems was truly represented. The model was adapted to the case of Sønderborg municipality in Denmark and the results show that three out of four interconnections are economic feasible in the present system. In the reference year (2013) total system costs were 4.1 % lower, while total primary energy supply was reduced by 1.76 %. For the year 2029, in which intermittent renewable energy sources are dominating the energy generation, total socio-economic costs were reduced by 5.9 %, CO2 emissions by 7.1 % and primary energy supply by 8.4 % after the adjacent district heating systems were connected. Hence, the integration of district heating systems have beneficial impact on the integration of intermittent renewable energy sources.