A generic stochastic network flow formulation for production optimization of district heating systems

District heating is an important component in the EU strategy to reach the set emission goals, since it allows an efficient supply of heat while using the advantages of sector coupling between different energy carriers such as power, heat, gas and biomass. Most district heating systems use several different types of units to produce heat for hundreds or thousands of households. The technologies reach from natural gas-fired and electric boilers to biomass-fired units as well as waste heat from industrial processes and solar thermal units. Furthermore, combined heat and power units (CHP) units are often included to use the synergy effects of excess heat from electricity production. We propose a generic mathematical formulation for the operational production optimization in district heating systems. The generality of the model allows it to be used for most district heating systems although they might use different combinations of technologies in different system layouts. The mathematical formulation is based on stochastic programming to account for the uncertainty of production from non-dispatchable units such as waste heat and solar heat. Furthermore, the model is easily adaptable to different application cases in district heating such as operational planning, bidding to electricity markets and long-term evaluation. We present results from three real cases in Denmark with different requirements.