The “APE – Appunti di Energia” series continues with a new indepth analysis dedicated to the European platforms for energy balancing. This APE provides a clear and structured overview of the European balancing architecture, explaining how common rules, harmonized products and shared digital platforms are transforming the operation of European power systems, making them more efficient, integrated, and resilient. This document presents the main regulatory and operational choices that have led to the construction of a harmonized European balancing market.

The notes illustrate how the European Union, after integrating the dayahead markets, is completing the path toward a fully unified electricity market also in the balancing segment. To achieve this, the SOGL and EBGL regulations were introduced to define common rules for frequency control, imbalance management, and the organization of reserve markets. In particular, the document highlights key regulatory decisions such as the adoption of the merit order for resource activation, the introduction of the Cross Border Marginal Price, the standardization of balancing products (FCR, aFRR, mFRR, RR) and the structuring of the entire system around concepts such as Synchronous Area, LFC Area, and Area Control Error (ACE).

The document also describes how cooperation among European TSOs materializes through three operational platforms: IN, dedicated to imbalance netting for automatically compensating opposite imbalances; PICASSO, which coordinates the activation of aFRR at European level through a centralized algorithm (AOF); and MARI, which plays an analogous role for mFRR. The closure of the TERRE platform is also recalled, made necessary by the new rules introduced by the Electricity Market Design Reform.

A dedicated section analyzes the functioning of netting and reserve activation processes, illustrating how the European algorithms incorporate network constraints, crossborder capacity, reserve requirements, and, more recently, also elastic demand components to improve the efficiency of aFRR activation.

Finally, the document outlines Italy’s role within the new European framework. Terna currently participates fully in IN and PICASSO and is planning its entry into MARI, while the evolution of the European platforms has required a substantial reform of the national dispatching system. This reform, implemented through the TIDE.