RTE deploys flow-based validation process for Core region intraday capacity calculation, replacing ATC method

RTE announced the deployment of a new Flow-Based validation process for intraday cross-border capacity calculation results (Core IDCC) within the Core region, to be put into production on 29 September 2026 with an application date of 30 September 2026, replacing the current ATC-based intraday validation process.

This methodology shift from ATC to Flow-Based validation for intraday capacity calculation directly affects how cross-border transmission capacity is computed and validated for intraday trading in the Core region, potentially changing available capacity levels, price formation dynamics, and operational security processes for TSOs and market participants relying on accurate intraday cross-zonal capacity.

Moving from ATC (Available Transfer Capacity) to Flow-Based methodology for intraday validation aligns the intraday timeframe with the flow-based approach already used in day-ahead capacity calculation in the Core region, improving consistency across timeframes under the CACM framework. Flow-based methods typically allow for more granular and network-realistic representation of cross-border constraints, which can increase available capacity and improve price convergence between bidding zones during intraday trading, but also introduces additional complexity in validation processes that TSOs and market participants must adapt to operationally.

Intraday Capacity Calculation Methodology (Core IDCC) under EU CACM Guideline

Application date for flow-based validation process (replacing ATC) in Core intraday capacity calculation · 30 Sept 2026

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