Optimal DHC energy supply harnessing its thermal mass

•DHC thermal mass and heat losses in energy supply are studied.•An Energy Management System is proposed to provide optimal supply strategies.•DHC thermal mass is used as energy storage increasing power plant benefits.•Heat losses are reduced by the use of an optimal supply temperature. Optimal supply strategies are a promising and inexpensive way to improve energy efficiency and to reduce expenditure in district network energy supply. These strategies aim to reduce heat losses by modifying the supply temperature within its working boundaries. Through supply temperature adjustment and network’s thermal mass it is possible to modify the energy stored in the network and to use it as an active energy storage. In this work, scenarios with variable and fixed supply temperature are compared during four weeks representing the different seasons. The simulations are carried out using an energy management system. Results of both scenarios for a district heating and cooling network placed in the Mediterranean region are presented and discussed.