Potential Ancillary Service Markets for Future Power Systems

Future renewable-based power systems require more flexible energy resources that provide ancillary services. Ancillary services help transmission system operators (TSO) and distribution system operators (DSO) operate their networks. It is thereby necessary to know the existing ancillary services’ technical requirements and market structures in order to design future ancillary or flexibility service markets. In this regard, this paper firstly introduces the existing TSO-level ancillary service markets in Nordic countries. Their technical requirements, capacity prices, and market outcomes are assessed based on the Finnish capacity markets. Then, the DSO-level markets are discussed by introducing the projects that develop markets for DSO needs. Finally, new ancillary service markets are proposed that are designed for the future renewable-based more decentralized system. In the proposed market, local flexible energy resources can provide active and reactive power related flexibility services for both TSO and DSO.