Paper Conference

Proceedings of uSim Conference 2018: 1st uSim Conference of IBPSA-Scotland

     

SOURCES OF ENERGY FLEXIBILITY IN DISTRICT HEATING NETWORKS: BUILDING THERMAL INERTIA VERSUS THERMAL ENERGY STORAGE IN THE NETWORK PIPES

Annelies Vandermeulen, Glenn Reynders, Bram van der Heijde, Dirk Vanhoudt, Robbe Salenbien, Dirk Saelens, Lieve Helsen

Abstract: An increasing share of intermittent renewable energy sources calls for more flexible energy systems. This flexibility - the capability of shifting energy use in time and/or magnitude - can be obtained, amongst others, by integration of thermal energy storage in district heating systems. Adequate control of storage systems allows increasing intermittent renewable energy supply and/or decreasing curtailment. In a district heating network, many different thermal energy storage systems are available, each with their own characteristics and dynamics. To facilitate an optimal selection and combination of these different storage systems, a flexibility characterization method was defined by IEA-EBC Annex 67. This paper verifies this characterization method by evaluating the energy flexibility provided by two sources inherently present in a district heating network, being the water thermal mass in the network pipes and the thermal inertia of the buildings connected to the network. The paper evaluates multiple scenarios, comparing different streets and small districts, and combining different dwelling types. The obtained energy flexibility characteristics shows that the network contribution is limited compared to that of the buildings’ thermal inertia, at least in the case of small networks. Furthermore, results show that the nonlinear characteristics of the district heating network, such as congestion, could complicate the aggregation of flexibility characteristics.
Pages: 114 - 121
Paper:
usim2018_025