Distribution-Level Flexibility Markets—A Review of Trends, Research Projects, Key Stakeholders and Open Questions

Abstract

In modern power systems high penetration of renewable energy sources and decentralized paradigm are regarded as the path toward more sustainable electricity landscape. This includes distributed energy resources whose intermittency and uncertainty may cause issues to the system operators. Distribution system operators have an obligation to ensure secure and stable system operation. Hence, they seek the most efficient methods to deal with these challenges. Flexibility procurement is considered as one of the prerequisites for painless and successful integration of renewable sources. Furthermore, distribution-level flexibility markets are modeled and tested to trade flexibility locally, solve congestion issues and defer grid expansion. This paper surveys the ongoing research in the field of flexibility markets, its design, open questions and most promising research projects. The key stakeholders are identified, overview of the current trends in the power system and research initiatives are presented, accompanied with the dilemmas being discussed in the power systems community.

Use of Flexibility in Distribution Networks

“…As observed in [4], all the TSO-DSO coordination mechanisms share similar prequalification, activation and settlement of flexibility resources, and in all mechanisms it is noticeable the evolution of the DSO role as it becomes more and more active participant. The review article [4] provides short overview of different TSO-DSO coordination mechanisms for procuring ancillary services in Europe.…”

“…They focus on increasing the operational flexibility of the electricity grid through enhanced grid monitoring and control capabilities and on facilitation of demand flexibility (demand response) respectively, and which, according to [5], gather 40% of the total funding. As observed in [4], local flexibility markets and flexibility in general are not so far from the infancy stage in the real-life. On the other hand, both academia and R&D oriented departments in the commercial sector are active in exploring various high-RES penetration models, flexibility provision, TSO-DSO coordination schemes and distribution level market models.…”

“…On the other hand, both academia and R&D oriented departments in the commercial sector are active in exploring various high-RES penetration models, flexibility provision, TSO-DSO coordination schemes and distribution level market models. Among surveyed papers, we single out the following works that provide overview of the most advanced and promising projects and platforms: [4,5,7,8]. Even though the literature provides insights on current state, what lacks is the pilot project and research on applicability in different markets around Europe.…”

Robust prequalification process of a distribution system operator considering N‐1 contingency

“…Similarly, the DSO finds the worst case of overflow using the maximization problem of the sum of flow rates on risky lines, Equation (9). From this, the DSO obtains the worst overflow state  c,s…”

“…Therefore, the distribution system should be managed by a distribution SO (DSO) [6,7]. Many studies regarding the relationship between DSO and DERA have been conducted [8][9][10]. The relationship between the DSO and DERA depends on the responsibilities and roles assigned to the DSO.…”