Long-Term Provision of Ancillary Services for the Electricity System Using District Heating Technologies – Modeling Study for the Case of Sweden

Abstract

The electricity sector is a key sector in the full energy system and is therefore crucial to consider in the transformation into a fossil-free energy system. Several ancillary services (AS) which operate at short-term scales, i.e., seconds up to multiple minutes, are implemented by the grid operators to balance the electricity system. District heating technologies, such as heat pumps (HPs) and combined heat and power (CHP), could potentially provide AS for the electricity system, thus improving the cost-efficiency of future energy systems. A long-term modeling approach using the TIMES framework is used in this study to analyze how the Swedish energy system can develop cost-efficiently when demands for energy and AS shall be fulfilled in several developed cases. The results are compared to cases without AS. The results show that DH technologies can cost-efficiently provide AS, mainly for the slowest upwards service, mFRR+. DH HPs and biomass CHP plants cover over half of the mFRR+ demand in the winter in southern Sweden, highlighting DH’s potential as a flexible resource. The results further show that new investments in DH technologies are attributed to energy demands, not AS provision, thereby indicating that AS provision does not incentivize new investments into DH technologies.