ACER: cross-border trade earns 32 billion euros a year, congestion cost 5.4 billion in 2025
Victoria Shinder1 min readThe EU Agency for the Cooperation of Energy Regulators published its 2026 Monitoring Report on electricity market integration on 4 November. It covers all market timeframes, cross-zonal capacity and congestion management.
On the positive side, ACER puts the economic surplus from cross-border trade at about 32 billion euros a year in the day-ahead market alone, and estimates that further integration across all markets could add at least 4 billion euros a year. Day-ahead trading has largely moved to 15-minute products, introduced on 1 October 2025, which now account for almost 90% of electricity traded in that market. Power purchase agreements increasingly pair renewable generation with storage.
The report also lists what is not working. Forward-market liquidity is concentrated in a few bidding zones and falls quickly for contracts beyond one year ahead. Price differences between bidding zones are widening, which makes the transmission capacity offered for cross-zonal trade more important. The requirement to make at least 70% of capacity available for cross-border trading is not yet fully implemented across the EU, and intraday and balancing markets are the most affected by limited cross-zonal access.
Congestion management is getting more expensive. Its cost reached 5.4 billion euros in 2025, up from 4.3 billion in 2024, with a growing share linked to voltage control following the Iberian blackout.
ACER's conclusion is that the full value of integration has not been realised and that fully applying existing rules, including the 70% minimum, would bring significant gains for consumers as renewable output grows.
What it means
The headline surplus is large, but the trend lines that matter for the next five years point the other way: wider price spreads, rising redispatch bills and a capacity rule still only partly met.