Enabling flexible CHP operation for grid support by exploiting the DHN thermal inertia

As a result of the increased penetration intermittent renewable energy sources, Combined Heat and Power (CHP) units are being looked upon as one sources that might provide for ever growing need electrical flexibility. However, CHP often considered must-run on grid their main purpose is generally to cover heat demand an adjoining District Heating Network (DHN). This paper demonstrates how CHP–DHN system may be used frequency reserve without excessively compromising lifetime CHP, using either specific storage tank or DHN’s thermal inertia in order compensate resulting imbalance. In latter case, it shown buffer tank, although smaller than Thermal Energy Storage (TES), required due restrictions acceptable DHN temperature gradients. both approaches, size has been mapped out considering reserve’s duration capacity. The results show simplistic static model sufficient design TES, while detailed dynamic simulation when storage, prevent overestimating flexibility system. research could assess potential improving systems flexibility, them reserves, tanks.