With respect to electrical grids and power systems there is a trend towards a greater penetration and subsequent utilization of distributed energy resources (“DERs”). DERs can provide services to both Distribution System Operators (“DSOs”) and Transmission System Operators (“TSOs”). Distributed energy resources are typically installed and interconnected to electricity networks that may or may not be completely controlled, monitored or analyzed by the power system operators themselves. If and when DERs are operated to provide system services and/or market actions, this may lead to system benefits and efficiency improvements, but can come with technical, economic, and jurisdictional challenges. Aggregators, DSOs, and TSOs, must be able to coordinate, monitor and dispatch resources as well as study and share information in a timely manner. Examples and recommendations for future coordination and interactions between the TSO, DSO, DER owners, and aggregators are presented and examined, in operation and market-based contexts, relevant to European and US electricity networks.
Keywords: Distribution system operator, utility, transmission system operator, distributed energy resources, wholesale markets, distribution-level markets, transmission-distribution coordination functions, electricity services.