RTE sets 08 October 2026 go-live for Core IDCC intraday capacity calculation validation to switch from ATC to Flow-Based methodology

RTE announced a new deployment date (application date 08 October 2026) for the Flow-Based methodology validation process for intraday capacity calculation (Core IDCC) within the Core region, replacing the current ATC-based intraday validation process.

This transition changes how intraday cross-border capacity is calculated and validated across the Core region, moving from Available Transfer Capacity (ATC) to Flow-Based methodology, which can materially affect the cross-zonal capacity made available to intraday markets and thus intraday price formation and liquidity between Core bidding zones.

The shift from ATC to Flow-Based capacity calculation for intraday timeframes in the Core region represents a structural change in how network constraints are translated into tradable cross-border capacity. Flow-Based methods typically allow more granular representation of network flows and can increase available capacity relative to ATC in some network conditions, potentially improving intraday liquidity and price convergence across Core bidding zones. However, it also introduces additional complexity in capacity validation and coordination among Core TSOs, with implications for operational security processes during the transition period. The announcement is an update to a previously communicated implementation timeline (a 'new date'), indicating this is a rescheduled deployment rather than a first announcement, though the source only supports this single new date as the actionable fact.

Core Intraday Capacity Calculation (IDCC) Methodology

Go-live of Core IDCC Flow-Based validation process (replacing ATC-based process) · 8 Oct 2026

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