Cross-zonal capacities and the 70% margin available for cross-zonal electricity trade (MACZT)

2023 Market Monitoring Report

EU rules require grid operators to make a 70% minimum amount of capacity on interconnectors available for electricity trading with neighbours by the end of 2025. It is ACER’s job to monitor how Member States are doing on reaching this 70% target, but ACER’s monitoring finds that the target is still far off.

Why is reaching the minimum 70% target important?

  • Delivering on the agreed minimum 70% target of interconnection capacity is crucial to achieving the ambitious political objectives set for renewable generation.
  • Reaching the 70% target will:
    • ensure security of supply;
    • mitigate price volatility; and
    • provide key flexibility to the market.
  • Building new lines is difficult and environmentally challenging: The 70% target allows for a more efficient use of existing lines.
  • The 70% target will become increasingly difficult and costly to reach. Progress towards the 70% target is unlikely to happen without tough trade-offs.

What is the report about?

ACER’s Report on cross-zonal capacities and the 70% margin available for cross-zonal electricity trade:

  • Highlights the need for maximizing cross-zonal trading to reach the EU’s clean energy goals;
  • Evaluates progress towards achieving the 70% target by the end of 2025;
  • Analyses the main barriers to cross-zonal trading and outlines what Member States and Transmission System Operators (TSOs) can do to lift them; and
  • Illustrates the impact on welfare and on price spikes of offering low cross-zonal capacity levels in day-ahead electricity markets.

ACER's public consultation in September 2023 collected stakeholders' views on the report's findings.

Cross-zonal capacities and the 70% margin available for cross-zonal electricity trade (MACZT)



  • Interconnection capacity available for cross-zonal trade of electricity remains low across the EU. The minimum 70% target of interconnection capacity is still far off for most Member States.
  • Reaching the 70% target is a collective effort: Each Member State’s actions (or inactions) impact other Member States and ultimately consumers.
  • Lifting both internal and cross-zonal constraints is necessary to achieving the 70% target. Old barriers persist:
    • Loop flows, i.e., internal trades within country A creating electrical flow through country B, thus creating congestion;
    • Insufficient and costly remedial actions;
    • No mechanism in place for sharing the cost of remedial actions.

Access the report.

See the corrigendum.

See the underlying dataset.


Interested in key findings? See the informative infographic.


Missed our webinar? See the slides and watch the recording.