ACER finds European grid investment nearly tripled

European annual electricity transmission investment increased from €10.4bn in 2019 to €30.5bn in 2025, according to the latest infrastructure monitoring by the Agency for the Cooperation of Energy Regulators (ACER). The regulator’s 2026 report finds that higher spending has not eliminated delays in cross-border projects or the operational cost of managing network constraints. Congestion relief actions cost €5.4bn in 2025, more than a quarter higher than in the previous year, while expanding renewable generation and new electricity demand continue to change the locations and timing of power flows.

The report assesses electricity, gas, and hydrogen infrastructure, whose investment requirements are changing at different rates. The electricity figures measure annual transmission spending, rather than a cumulative total or the value of new cross-border links alone. Investment rising to €30.5bn in 2025 demonstrates the scale of network activity, while ACER’s monitoring also tracks how approvals and congestion affect performance. The returns from higher spending depend on completed connections, access to existing capacity, and the timely operation of reinforced assets.

Cross-border projects remain vulnerable to lengthy approval procedures. ACER reported that, on average, 22% of electricity projects of common interest and projects of mutual interest are delayed each year, primarily because of permitting. The agency estimated that a one-year delay to cross-border infrastructure could result in around €4bn in lost economic welfare. That estimate describes the system-level benefit forgone through delay, rather than a direct construction penalty imposed on the project developer or a guaranteed cost for every individual connection.

Congestion-management costs are also rising as network capacity struggles to accommodate scheduled transfers. When the physical network cannot accommodate all commercially scheduled power flows, transmission operators may need to take remedial actions to maintain secure operation. Those measures can include changing generation dispatch or adjusting operating arrangements within the limits of the existing infrastructure. ACER recorded €5.4bn in congestion-management costs for 2025, an increase of more than 25% from 2024. Such expenditure may be necessary for system security, but it also indicates pressure on the network while reinforcement is still being delivered.

Congestion income from day-ahead electricity markets exceeded €9bn in 2025, approximately seven times the 2019 figure. ACER also found that about 60% of the total available congestion income, equivalent to roughly €12.5bn, was being retained for later use instead of being applied to cross-border networks or tariff reductions. The €12.5bn is a stock of available funds, not the amount collected solely during 2025. Those funds sit within a regulatory framework that governs how system operators can use congestion revenue, raising questions about the speed at which available resources can support network investment.

EU households have faced rising network charges alongside the investment increase. Average household network costs in the EU rose by 40% between 2019 and 2025, reaching €84/MWh, and represented around 28% of an average electricity bill. These figures describe network-related household costs across the assessment and do not establish an identical charge for industrial customers or a common national tariff. They nevertheless show how infrastructure investment and system operation affect the costs recovered through electricity networks.

More renewable generators are connecting in locations distant from established demand centres, while electrified heating, transport, and data centres change where network capacity is required. Those shifts place different demands on transmission corridors and local connection points. Reinforcement can increase the physical transfer capability of a line or substation, but delivery depends on land access, planning permission, specialist equipment, and commissioning work. ACER’s figures show that high spending and continued congestion can exist together where network constraints persist before infrastructure is completed.

The agency recommended measures to obtain more capability from existing infrastructure, including demand response, market-based congestion management, grid-enhancing technologies, cost-reflective tariffs, and full implementation of the requirement to make 70% of cross-border capacity available for trade. It also called for more integrated planning across electricity, gas, and hydrogen networks, along with more predictable permitting. Those proposals sit alongside questions about how the benefits and costs of cross-border projects should be allocated among network users and countries.

Gas and hydrogen investment is following a different pattern from the rapid expansion of electricity networks. ACER reported EU electrolyser capacity of approximately 0.49GW, well below the 30–58GW envisaged for 2030 in national strategies and EU scenarios, while gas demand remained below its earlier baseline. For electricity transmission, the continuing tests will be whether new assets enter service on schedule and whether operators can reduce expensive congestion measures. ACER’s next infrastructure monitoring report is due in 2028, providing a later reference point for investment, delivery, and costs to network users.