TSO-DSO coordination schemes to leverage distributed energy resources
Energy systems are undergoing radical changes as part of their modernisation process worldwide. For instance, the increased levels of penetration of distributed energy resources (DERs) such as distributed generation, electric vehicles, demand response and storage devices transform distribution systems from energy supply to energy production/supply points and pave the way to a more decentralised power system architecture. Historically, transmission system operators (TSOs) were responsible for operating the system in a reliable, sustainable and cost-efficient way. However, such an approach does not fully leverage DERs that can be used as generation and flexibility resources. New coordination frameworks need to be investigated between transmission and distribution systems to accommodate a proactive management of DERs with the help of distribution system operators (DSOs). A successful coordination framework would lead to avoidance of costly distribution network infrastructure upgrades; large-scale integration of renewable resources; and greater consumer control of their electricity. However, there are several challenges in achieving increased levels of coordination between TSOs and DSOs from both computational/technical as well as institutional perspectives. For example, in the computational aspect the underlying physics of low-voltage networks and the intertemporally coupling of DERs result in large-scale optimisation problems. From an institutional point of view, there are privacy concerns as well as cases where individual costs of TSOs or DSOs might be higher compared to other coordination schemes; thus rising problems in a fair allocation of costs between TSO and DSO.