From partial optimization to overall system management – Real-life smart heat load control in district heating systems

District heating (DH) customers are becoming increasingly interested in finding ways to decrease their heat consumption and costs. A general assumption is that demand side management (DSM) actions in heating stabilize consumption profiles, reducing consumption and peak demand. While several simulation studies have shown these assumptions to be true, much less is known about how real-life DSM actions affect the heat consumption profiles of buildings. This study analysed real-life consumption data from 109 DH customers over a period of four years. Thirty-one of those customers implemented DSM actions including permanent energy conservation and demand response actions with temporal effects with autonomous control (called Smart control, SC). The remaining 78 customers did not implement DSM and are used as a reference group. This study compared changes in the SC customers’ heat consumption profiles against the reference group and analysed how SC measurements reflect to DH system. The results show that these DSM actions decreased the heat consumption and costs for the customers but simultaneously increased short-term variations of heat load. This study highlights the need for greater co-operation between DH companies and their customers to develop more effective DSM control strategies that can provide better solutions for the whole system.