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By NiLu Updated

Electric grid in Europe — structure and bottlenecks

ENTSO-E and ACER coordinate codes and adequacy in Europe — they don't operate the grid or publish a single queue; the connection bottleneck is national.

Article summary

  • Electric Europe is not one single grid nor one single queue: ENTSO-E coordinates codes, planning, and adequacy across dozens of TSOs, but real-time operation and connection waitlists stay with each country's TSO and regulator.
  • Physics also divides the continent: there are several distinct synchronous areas (Continental Europe, Nordic, Ireland/Northern Ireland, among others) — Europe ≠ a single AC machine.
  • There is no pan-European connection-queue dataset in MW, among this dossier's sources, comparable to the American ISOs' — what exists are national waitlists and policies.
  • Ireland and the Netherlands illustrate this: large-load and general connection bottlenecks show up at the national regulator and operator, not in an ENTSO-E or ACER product.

ENTSO-E and ACER: coordination, not a single operator

ENTSO-E (European Network of Transmission System Operators for Electricity) is an association bringing together 40 member TSOs from 36 countries, with a legal mandate under European Union law, for the safe and coordinated operation of one of the world’s largest interconnected electricity systems. [1] This doesn’t make ENTSO-E a single operator, in the style of a continental ISO: ENTSO-E’s own page on system operations states that real-time security remains the core activity of each TSO, and that the System Operations Committee functions as a cooperation platform among different synchronous areas — not as a single European control room. [4]

Alongside ENTSO-E is ACER (the European Union Agency for the Cooperation of Energy Regulators). Regulation (EU) 2019/942 defines ACER’s purpose as assisting national regulatory authorities (NRAs) in exercising, at the Union level, their regulatory tasks, and, where necessary, coordinating that action and mediating or resolving disagreements among them — contributing to common regulatory practices. [2] ACER does not replace the national regulator: who decides connection policy in each country remains the local NRA — the CRU in Ireland, the ACM in the Netherlands, and so on, as we’ll see in the two hubs further ahead.

Article 30 of Regulation (EU) 2019/943 details what falls to ENTSO-E: developing network codes; adopting and publishing, every two years, a Union-wide Ten-Year Network Development Plan (TYNDP) — explicitly non-binding; preparing and adopting proposals related to the ERAA (European Resource Adequacy Assessment); adopting the cooperation framework for the RCCs (Regional Coordination Centres); and adopting common network-operation tools. [3] All of these are planning, code, and adequacy products — not dispatch, nor a connection queue.

Europe is not one synchronous machine

An easy mistake to make is treating “the European grid” as a single AC network. ENTSO-E itself organizes its system operations by Regional Groups, aligned with distinct synchronous areas — among them Continental Europe; Nordic (which brings together Eastern Denmark, Finland, Norway, and Sweden); and Ireland/Northern Ireland. [4]

Ireland is the clearest example of this. The EirGrid Data Centre Constrained Area Overview, from May 2026, describes Ireland as a synchronous island, with limited non-synchronous (HVDC) connections, and explicitly states that the country is not connected to the European electricity system through traditional AC circuits. [5] This means that Irish connection physics and policy do not bend to a single “Continental Europe AC” model — and it’s one of the reasons Ireland works well as one of this text’s two national hubs.

Adequacy: the ERAA and national NRAAs

The ERAA (European Resource Adequacy Assessment) is the main pan-European product on “will the grid have enough energy.” The ERAA 2024 Executive Report, in the version approved and amended by ACER (August 2025), describes it as a probabilistic pan-European resource-adequacy assessment, with a horizon of up to ten years, under the framework of Regulation (EU) 2019/943; results and identified needs are scenario-dependent — they should not be cited from drafts prior to ACER approval without that caveat. [6] [7]

Even so, the ERAA is not the only number that matters. The Executive Report itself states that, together with national resource adequacy assessments (NRAAs) that identify specific concerns, the ERAA 2024 supports the Member States — and that at least 12 Member States complement the ERAA with their own NRAA, to capture local circumstances that the pan-European assessment may not resolve, given the system’s size and complexity; assumptions adopted in one country can affect the results calculated for neighboring ones. [6] In other words: adequacy in Europe is a two-layer reading — pan-European and national — and there is no single “European number” for capacity deficit that replaces the two.

Cross-zonal congestion: market, not connection queue

Another number that circulates a lot is cross-zonal congestion — and it’s worth being clear that it measures market access, not the connection queue for a new project. ACER’s Monitoring Report 2025 on cross-zonal trade capacities recalls that EU law requires TSOs to offer at least 70% of the physical capacity on relevant lines for trade between bidding zones. In 2024, TSOs in the Core region made available, on average, 54% on the most congested lines; remedial actions exceeded 60 TWh, at a cost of €4,3 billion; and the report estimates that meeting the 70% minimum in the Core, in 2024, would have generated about €580 million in welfare gains. [8]

This is ACER’s institutional reading — attributed to the agency, not a verdict by NiLu on TSO performance. On the operational side, grid-security constraints, derogations, and transition periods limit how much capacity can be offered immediately on each congested line; TenneT’s own page on congestion in the Netherlands, which we’ll see in the Netherlands hub, documents this kind of operational limit leading to waitlists until grid reinforcement. [8] The two readings — market efficiency on one hand, operational security on the other — are legitimate, attributable perspectives from their sources; neither should be read as “the European connection queue,” because what is being measured here is access to trading capacity between already-existing bidding zones, not requests from new projects awaiting connection.

TYNDP: the gaps are still “for opinion”

The Union-wide TYNDP is, as we’ve already seen, biennial and explicitly non-binding. [3] The TYNDP 2024 Infrastructure Gaps Report, published on April 9, 2025 and marked as for opinion — that is, still subject to comment and approval, not a final package —, estimates, in the study’s own framing, that by 2030 an additional capacity of about 88 GW cross-border and 56 GW of storage would minimize system costs; by 2040, the estimate rises to about 108 GW of additional cross-border capacity (including approximately 20 GW of offshore hybrids). The report also states that reaching this level of cross-border exchange will create new reinforcement needs for internal grids in the national European systems. [9]

Two caveats matter here. First, the status: as long as the TYNDP 2024 package is not finalized by ACER, the European Commission, and the Member States, these GW figures are study estimates, not an already-firmed infrastructure need. Second, and more important so as not to confuse sections of this text: the internal reinforcement need mentioned by the TYNDP is a general consequence of increased cross-border trade at the planning level — it is not the same mechanism, nor the same decision, as a specific country’s data-centre connection policy (as we’ll see next in Ireland). A cross-border gap identified by ENTSO-E is not a national reinforcement fork decided because of data centers; they are two different conversations, at different layers.

Ireland hub: a synchronous island under data-centre pressure

Ireland probably concentrates the most documented example of data-centre pressure on a national grid in Europe. The CRU (Commission for Regulation of Utilities), in a decision of December 12, 2025, states that data centres went from about 5% to 22% of Ireland’s national electricity demand between 2015 and 2024; the EirGrid forecast cited by the CRU projects data-centre demand rising from 9,4 TWh in 2025 to 14,6 TWh in 2034 — about 31% of national demand in that year. [10]

To handle this, the CRU’s connection policy requires new data centres to match dispatchable generation or storage to their Maximum Import Capacity (MIC) and to obtain at least 80% of their annual demand from additional indigenous renewable sources, following a six-year glide path; the policy also distinguishes constrained from unconstrained areas. [10] The EirGrid Data Centre Constrained Area Overview from May 2026 gives the scale of the problem: the all-Ireland peak sits around 7,5 GW; about 2 GW of data centres are already contracted (mostly in the Greater Dublin area), nearly a third of demand if fully utilized; and EirGrid’s market intelligence pointed, in the same publication, to additional interest on the order of 6 GW — a figure attributed to market intelligence, not to confirmed formal requests. [5]

The process behind these decisions is national, and distinct from any pan-European product: the EirGrid Data Centre Connection Offer Process and Policy (DCCOPP), in its version 3 from May 2026, documents the connection-offer process for data centres in Ireland, with an operational threshold cited in the package itself starting at 1 MVA, under the rules and assessments of the Irish system (including the constrained-area concept). It is not the TYNDP, it is not the ERAA — it is national regulation and operation. [11]

Netherlands hub: TSO and DSO queues

In the Netherlands, evidence of a national connection queue is even more explicit, because the transmission operator and the distribution operators publish formal waitlist figures. The Stand van de Uitvoering publication by Netbeheer Nederland, from September 2025 (with data from the first half of that year), reports, for offtake: the regional DSOs together have 14.044 unique waitlisted requests, totaling 9.131 MW; TenneT, as TSO, has 212 unique offtake requests, totaling 38 GW, and, on the injection side, 161 requests, totaling 34 GW — including firm and non-firm transport rights. [12]

TenneT’s page on congestion in the Dutch grid explains why: demand — from data centres, horticulture, solar power, among other uses — exceeds grid capacity in many locations, resulting in waitlists until reinforcement is completed; the objection and regulatory path, in this case, goes through the ACM, the Dutch national regulator, not through ACER as manager of any queue. [13] It’s worth noting that the Netherlands is in the Continental Europe synchronous area and participates in the Core capacity-calculation region (CCR) mentioned in the congestion section — but being part of cross-zonal market coupling does not equate to having free local connection capacity available; these are two different layers of the same grid.

It’s worth noting, as a process note rather than a third hub in this cycle, that Germany also recently changed its national queue logic: in a joint statement of February 5, 2026, Germany’s four TSOs (including 50Hertz) announced the introduction, starting the 1st of April 2026, of a “Reifegradverfahren” (maturity-grade process) for storage, large loads, and data centres, replacing the first-come-first-served criterion after accumulating about 717 transmission connection requests, totaling approximately 270 GW, by the end of the third quarter of 2025. [14] The German example reinforces this section’s central point: each country solves its queue in its own way, and none of them is published as a single ENTSO-E product.

In fact, in none of the primary sources consulted in this dossier — ENTSO-E, ACER, EU legislation, or the Irish and Dutch hubs themselves — is there a pan-European connection-queue dataset, whether for generation or load, comparable to the queues published by the American ISOs. What exists are waitlists and connection policies published by each country’s TSO, DSO, or NRA.

Uncertainties

  • There is no indication, among the sources consulted, that an official pan-European connection-queue dataset in MW, published by ENTSO-E or ACER, comparable to the American ISOs’ queues, is forthcoming — today the answer to that question is the documented absence, plus the national hubs.
  • It is not known how much the numbers in the TYNDP 2024 Infrastructure Gaps Report (about 88, 56, and 108 GW) will change once the package is finalized by ACER, the European Commission, and the Member States — today it remains marked as for opinion.
  • It is not possible to say which ERAA 2024 LOLE or capacity-need results remain stable under alternative scenarios and national NRAAs, versus which are sensitive to cross-Member-State assumptions.
  • It is not clear whether the constrained- and unconstrained-area heat maps, cited as forthcoming in the EirGrid package from May 2026, will change the spatial reading of the Irish bottleneck beyond what is already documented in the Constrained Area Overview.
  • This cycle treated Ireland and the Netherlands as the two box hubs; a fine-grained look at the Nordics, the Baltics, or Great Britain was not opened here and would be left for a future cycle, if needed.

References

  1. ENTSO-E — Mission Statement. ENTSO-E. Accessed August 09, 2026.
  2. Regulamento (UE) 2019/942. EUR-Lex. Accessed August 09, 2026.
  3. Regulamento (UE) 2019/943. EUR-Lex. Accessed August 09, 2026.
  4. ENTSO-E — System Operations. ENTSO-E. Accessed August 09, 2026.
  5. EirGrid — Data Centre Constrained Area Overview (May 2026). EirGrid. Accessed August 09, 2026.
  6. ERAA 2024 Executive Report (version approved and amended by ACER, August 2025). ENTSO-E. Accessed August 09, 2026.
  7. ACER — Decision 07/2025 on ERAA 2024. ACER. Accessed August 09, 2026.
  8. ACER — Monitoring Report 2025: Cross-Zonal Electricity Trade Capacities. ACER. Accessed August 09, 2026.
  9. ENTSO-E — TYNDP 2024 Infrastructure Gaps Report (for opinion, April 9, 2025). ENTSO-E. Accessed August 09, 2026.
  10. CRU — The CRU Publishes Its Decision on New Electricity Connection Policy for Data Centres (December 12, 2025). Commission for Regulation of Utilities. Accessed August 09, 2026.
  11. EirGrid — Data Centre Connection Offer Process and Policy, v3 (May 2026). EirGrid. Accessed August 09, 2026.
  12. Netbeheer Nederland — Stand van de Uitvoering, halfjaarpublicatie (September 2025). Netbeheer Nederland. Accessed August 09, 2026.
  13. TenneT — Congestion of the Grid. TenneT. Accessed August 09, 2026.
  14. 50Hertz et al. — Comunicado sobre o Reifegradverfahren (February 5, 2026). 50Hertz. Accessed August 09, 2026.