A novel statistical framework for modeling active and reactive power flexibility in a balancing service provider’s distributed energy resource portfolio

Distributed energy resources can play a crucial role in providing ancillary services at both transmission and distribution level, aimed at enhancing load balancing and supporting overall grid resilience and stability. However, the effective utilization of these services remains challenging for Balancing Service Providers, as the actual capabilities of the regulating distributed energy resources are often partially known. To address this challenge, this paper introduces a new and comprehensive statistical framework for flexibility modeling and characterization, based on the concept of active-reactive power feasible operating regions that properly account for the distributed energy resource technical limits and uncertainty. The proposed novel statistical algorithm evaluates the flexibility contribution of both individual distributed energy resources and their aggregation, by incorporating into the formulation their service provision costs and reliability information. The derived feasible operating regions are particularly valuable for Balancing Service Providers, which can leverage them to assess market potential, optimize participation strategies, and design portfolios of contracted resources in an aggregated and probabilistic framework. Numerical results, based on illustrative case studies and real-world distributed energy resource data from the city of Milan, confirm the effectiveness of the proposed framework for determining, from a probabilistic standpoint, their ancillary service potential.