On this page · 12 sections
- What is due, and when
- Who must report: the 500 kW test
- What you report under Annex I and Annex II
- The KPIs the Commission calculates
- The first EU labels: what the rating act adds
- Which version of the rules applies to the 2027 filing?
- Practical data collection
- The European database, step by step
- Worked example: from meter readings to label
- Checklist: November 2026 to August 2027
- How eCorpIT can help
- References
Summary. If you operate an EU data centre with at least 500 kW of installed IT power, Delegated Regulation (EU) 2024/1364 requires you to send its 2026 information and key performance indicators to the European database on data centres by 15 May 2027. The duty covers enterprise, colocation and co-hosting sites, site by site. You report raw values such as IT power, energy, water, reused heat and renewable sourcing, and the Commission calculates PUE, WUE, ERF and REF. In the first round 770 sites reported, about 36% of those thought to be in scope, with energy-weighted averages of PUE 1.36, WUE 0.58 m³/MWh and REF 0.86. The 2027 filing matters more. On 21 September 2026 the Commission adopted C(2026) 3472, a rating act that turns reported data into public A to G classes for PUE and WUE, with the first labels due by 15 August 2027. On 7 November 2026 it was still in scrutiny and not yet in the Official Journal. It also changes several definitions, so collect 2026 data that works under both versions and check your EU Login access and IT metering point now.
About this article. For data centre operators, colocation providers, tenants and facilities teams. We read Delegated Regulation (EU) 2024/1364 as published on 17 May 2024, with its corrigendum of 31 October 2024, and the Energy Efficiency Directive (EU) 2023/1791 in its consolidated version of 5 August 2026, which leaves Article 12 unchanged. We also read the rating act C(2026) 3472 and its annexes as adopted on 21 September 2026, the Commission's report COM(2026) 500, the database FAQ (version 1.9), the reporter guide and Ireland's guidance (archived copy only), all on 7 November 2026. This is not legal advice; templates and national procedures can change. No vendor paid for inclusion. Researched with AI assistance and reviewed by our editorial team.
What is due, and when
Article 12 of the Energy Efficiency Directive makes Member States require data centres of 500 kW or more to publish set information yearly, and tells the Commission to run a European database. Delegated Regulation (EU) 2024/1364, announced on 15 March 2024, sets the detail and puts the duty on operators. Each filing covers the previous calendar year, and a site that has run for less than a year reports only for its period of operation.
| Date | What happens | Status |
|---|---|---|
| 14 March 2024 | Delegated Regulation (EU) 2024/1364 adopted | In force since 6 June 2024 |
| 15 September 2024 | First filing, covering 2023 data | 770 sites reported |
| 15 May 2025 and 2026 | Second and third filings, covering 2024 and 2025 data | Passed; analysis in preparation |
| 21 September 2026 | Rating act C(2026) 3472 adopted; report COM(2026) 500 published | Act in scrutiny |
| About 21 November 2026 | Two-month scrutiny ends, unless extended by two months | Pending |
| 14 December 2026 | Consultation on minimum performance standards closes | Open |
| 15 May 2027 | Fourth filing, covering 2026 data | Upcoming |
| 15 August 2027 | First labels, if the rating act is in force | Planned |
| 31 December 2028 | First review of the rating scheme | Planned |
Sources: the two regulations, the Council's receipt, and the Commission's report, data centre page and consultation notice.
The rating act does not move the 15 May date. It adds a public label at the end, plus a step in which each Member State tells the database by 15 August that national reporting is complete. Binding performance floors are a separate track, with a proposal planned for the second quarter of 2027; see our guide to EU minimum performance standards for data centres.
Who must report: the 500 kW test
Per the Commission FAQ and Ireland's guidance, you must report if you operate an EU data centre with installed IT power demand of at least 500 kW. The definition of a data centre comes from Annex A, point 2.6.3.1.16, of the energy statistics regulation (EC) No 1099/2008.
Installed IT power (PDIT). This is the nominal power of the network, server and storage equipment in the computer room, in kW. The test uses installed, not design, capacity, even if the site never runs at full load. Without an inventory you may report the rated IT load, usually the UPS capacity, which often overstates IT power.
Per-site counting. Sites at different addresses are separate data centres. Server rooms on one site may be reported together or separately, but two 300 kW buildings on one site count as one 600 kW data centre. Office IT, scattered single servers or racks and telecom equipment are excluded.
Owner and operator. The owner field means the owner of the building, not the servers. The Directive names owners and operators, but the delegated regulation puts the reporting duty on the operator, a point Latham & Watkins flags for leased sites.
National schemes. Where a Member State runs its own scheme, operators report through it. The March 2026 contact list marks Germany and the Netherlands as running one. Germany also reaches sites from 300 kW, the Commission's report notes; our article on the German 100% renewable rule covers the bill that would change that.
Defence and voluntary entrants. Sites serving only defence and civil protection are already outside Article 12, and the rating act writes that exemption into the reporting regulation. Once it applies, sites below 500 kW may join voluntarily, as may sites not yet operating, which report the KPIs they expect after two calendar years of operation and then switch to actual data.
Enforcement. Penalties are set nationally, and the Commission says it will step up enforcement. A site that does not file gets no label.
What you report under Annex I and Annex II
Operators report raw data; the Commission calculates the indicators. Letters refer to points in Annex II of the current 2024 text.
| Data | Unit | Current method | Source on site |
|---|---|---|---|
| Name, owner, operator, location, type, start date, redundancy | Text | Annex I | Asset register; design files |
| Installed IT power, PDIT (a) | kW | Nominal total, or rated IT load | DCIM inventory |
| Total and computer room floor area (b, c) | m² | Built-up area including plant | Drawings |
| Total energy EDC, with generator share EDC-BG (d) | kWh | EN 50600-4-2 or equivalent | Utility meters; fuel logs |
| IT energy, EIT (e) | kWh | Category 1, at UPS output | UPS meters |
| Grid functions (f); battery capacity for the grid (g) | Yes or no; kW | Annex II | Flexibility contracts |
| Total water (h); potable water (i) | m³ | EN 50600-4-9 | Water meters and bills |
| Waste heat reused (j); waste heat temperature (k) | kWh; °C | EN 50600-4-6 or equivalent | Heat meters |
| Lowest supply-air setpoint (l); refrigerants (m) | °C; list | Annex II | BMS; F-gas records |
| Cooling degree days (n) | Degree days | Eurostat and JRC, base 21 °C | Public dataset |
| Renewable energy: total, GOs, PPAs, on-site (o to r) | kWh | Annex II | GO statements; PPA settlements |
| ICT capacity, CSERV and CSTOR | SERT performance; PB | Annex II, point 2 | Procurement records |
| Data traffic in and out | GB/s; exabytes | Annex II, point 3 | Network monitoring |
Annex II also requires a record of measurement points and devices kept for at least 10 years. The FAQ says the CEN/CENELEC standards are a benchmark, not a purchase requirement: ISO or open methods, such as the Climate Neutral Data Centre Pact's, are acceptable if the result matches the definitions.
The KPIs the Commission calculates
The FAQ says the Commission calculates PUE, WUE and ERF itself, and REF follows the same Annex III logic. Averages below are from the first round (2023 data, reported in 2024), weighted by energy use.
| Indicator | Formula | EU average, first round | On the 2027 label? |
|---|---|---|---|
| PUE, Power Usage Effectiveness | EDC ÷ EIT | 1.36 (national range 1.15 to 1.66) | Yes, class A to G |
| WUE, Water Usage Effectiveness | Water input ÷ EIT; amended to freshwater input ÷ EIT | 0.58 m³/MWh (0.07 to 1.28) | Yes, class A to G |
| ERF, Energy Reuse Factor | Waste heat reused ÷ EDC | About 1.8% of heat reused; 67 sites reported reuse | No score; readiness shown |
| REF, Renewable Energy Factor | Renewable energy ÷ EDC | 0.86 | Through the energy-source breakdown |
| LEEF, Low-Emission Energy Factor (new) | Renewable plus nuclear energy ÷ EDC | Not yet reported | Through the energy-source breakdown |
Sites of 500 kW to 1 MW averaged a PUE of 1.64, and the WUE average leaves out sites reporting no water. Over 70% of sites matched all their electricity with renewables over the year, but much of it came from PPAs and guarantees of origin not tied to local or new generation. LEEF comes from the rating act's amended Annex III.
The first EU labels: what the rating act adds
Annex I of the rating act sets seven classes for each graded indicator.
| Class | PUE | WUE (read as m³/MWh) |
|---|---|---|
| A | 1.15 or lower | 0.1 or lower |
| B | Above 1.15 to 1.25 | Above 0.1 to 0.2 |
| C | Above 1.25 to 1.35 | Above 0.2 to 0.4 |
| D | Above 1.35 to 1.5 | Above 0.4 to 0.6 |
| E | Above 1.5 to 1.7 | Above 0.6 to 0.8 |
| F | Above 1.7 to 1.9 | Above 0.8 to 1.0 |
| G | Above 1.9 | Above 1.0 |
The annex prints no WUE unit. The 2024 formula divides water in m³ by IT energy in MWh; the amended formula says kWh, which would put every site in class A. The thresholds fit the m³/MWh scale in the Commission's report (equal to litres per kWh), so we read them that way. On that reading, the first-round EU averages are class D for both indicators.
The label also shows the site name, type, operator, location, size category, reporting period, entry into operation, a QR code, cooling degree days, grid flexibility, and whether the site is waste heat reuse ready, meaning fitted to hand heat to an outside user. It splits total energy into renewable and nuclear sources (on-site, PPA, guarantee of origin) plus unidentified energy. Two totals show PPAs and guarantees of origin passing stricter tests, marked NC: the asset was commissioned or substantially refurbished within 10 calendar years before the reporting year, and guarantees of origin must also match the consumption period within the same bidding zone or Member State. The Commission frames this as showing support for new clean generation.
How labels work:
- Labels are generated by 15 August 2027 and yearly after, for sites that reported.
- A label runs from 15 August to 15 August, extended to 31 December at the latest if the Member State has not confirmed that reporting is complete.
- Labels are public in all EU languages. Operators must provide theirs on request, via a free website or database link, and must not display look-alikes.
- Other site-level data stays confidential. A common Commission document will explain how climate, size, age, type and water stress affect PUE and WUE.
Latham & Watkins reads the act as having no formal appeal route, so an accurate filing is your main lever on the label. A first review is due by the end of 2028.
Which version of the rules applies to the 2027 filing?
The Council received the act on 21 September 2026, so the two-month objection window runs to about 21 November 2026, and the Parliament or the Council can extend it by two months. With no objection, the act is published in the Official Journal and enters into force 20 days later. That could fall during the 2027 window; we found no template date.
Collect 2026 data that satisfies both versions. The key amendments:
- Freshwater input (WIN-FRE) replaces potable water, using the Water Framework Directive definition unless national law has one, and excluding return flows from recirculating cooling. WUE becomes freshwater over IT energy.
- IT energy moves from the UPS output to the rack connection (category 3), with the PDU (category 2) as fallback.
- Generator energy (EDC-BG), already separate, now covers any on-site generation that is not low-emission, maintenance runs included.
- Nuclear sourcing gets its own fields (ENUC-GOO, ENUC-PPA, ENUC-OS), NC subsets are reported separately, and PPAs and guarantees of origin must come from an interconnected bidding zone.
- Location moves to a NUTS3 code, and a site not yet operating enters DESIGN with an estimated start year.
- Certification of reported data is new: third-party validation or self-certification.
- Floor area includes roof space used by cooling plant; EDC is limited to computer rooms and their plant in mixed-use buildings and excludes energy used to upgrade reused heat.
- Data traffic indicators are deleted, cooling degree days are filled in automatically, and reuse readiness becomes a yes or no field.
- Colocation coverage estimates for ICT capacity are no longer limited to the first two periods.
The amended Article 3 also asks for dependable, repeatable methods or well-founded estimates, and adds a market surveillance step. Keep your calculation workbook; an authority would likely ask for it first.
Practical data collection
Total energy (EDC). Measure at the input to the data centre system, before the supply transfer switchgear, at every supply including back-up generation. In a mixed-use building, limit EDC to the computer rooms and their plant and document estimates, which the FAQ accepts where shared systems lack meters.
IT energy (EIT). The 2024 text measures at every UPS feeding IT; the amended text prefers the rack connection, then the PDU. Each step closer to the racks leaves more losses outside EIT and raises PUE. Pick a point you can defend and keep it.
Water and setpoints. Count all water entering for data centre functions, excluding sanitary use. Report the lowest supply-air setpoint averaged over the year, or 0 if there is none, and every refrigerant in use.
Energy sourcing. Guarantees of origin count only if bought and cancelled for the site; a company may allocate them across sites if each is used once. On-site renewables need none, but any issued must be owned and cancelled by the site. Nuclear PPAs now count as low-emission; see our note on nuclear PPAs for AI data centres.
ICT capacity. CSERV sums SERT-based PerfCPU values for servers; CSTOR sums raw storage in petabytes. Both cover at least equipment installed after the regulation took effect; the FAQ counts from 14 March 2024, the adoption date, though entry into force was 6 June 2024. The FAQ suggests requiring PerfCPU values by CPU SKU in server contracts.
Colocation tenants. Since 2024 colocation operators may collect tenant data anonymously and state the share of computer room floor area their figures cover. The FAQ treats these indicators as optional for colocation in at least the first two periods, with at least 90% of reported values based on real data. Tenants may get a data request early in 2027.
The European database, step by step
The database sits on the Commission's reportENER policy reporting platform. Based on the FAQ and reporter guide:
- Contact your national authority first. The Member State coordinator must register your organisation as a reporting entity before you request access. The Commission's contact list was last updated on 11 March 2026.
- Create an EU Login with a stable, role-based email; a new email means a new identity without earlier privileges.
- Request a reporting entity representative account, plus the data uploader role where there is no national scheme. One account covers all your sites in a country.
- Get a ReferenceID for each site. Member States set the format, for example LU-0001-001, and the ID stays with the site when the owner changes.
- Enter Annex I before Annex II, and re-create sites yearly if entering by hand; nothing carries over.
- For bulk upload, build XML against the current XSD template. The platform rejects non-matching files but has no validation tool, so the FAQ suggests checking locally, for example with Python's lxml. The replace option removes every existing record for your entity.
- Download a copy of your submission. The Member State coordinator then freezes the data for checks and can reopen it.
Worked example: from meter readings to label
A hypothetical 1.2 MW enterprise data centre, with invented 2026 figures, rated under the amended rules:
| Input | Value |
|---|---|
| EDC, total energy | 7,560 MWh, including 60 MWh from back-up generators |
| EIT at PDU level (category 2) | 5,600 MWh |
| EIT at rack level (category 3) | 5,450 MWh |
| Freshwater input | 2,500 m³ |
| Renewable PPA, wind farm commissioned 2021 | 4,000 MWh |
| Guarantees of origin, hydro plant commissioned in the 1980s | 3,000 MWh |
| Waste heat reused | 0 MWh; no heat-extraction interface |
PUE. At PDU level, 7,560 ÷ 5,600 = 1.35, class C. At rack level, 7,560 ÷ 5,450 = 1.39, class D. Same building, different class, depending on where EIT is measured.
WUE. 2,500 ÷ 5,600 = 0.45 m³/MWh, or 2,500 ÷ 5,450 = 0.46. Both are class D.
REF and LEEF. (4,000 + 3,000) ÷ 7,560 = 0.93, and LEEF is the same with no nuclear supply. The wind PPA passes the 10-year asset test, assuming an interconnected bidding zone, so the label shows 4,000 MWh of NC PPA energy. The hydro certificates fail the asset-age test, so the NC guarantee of origin total is zero. The remaining 7,560 - 7,000 = 560 MWh, including generator output, sits outside the low-emission categories.
ERF. ERF is 0; the label shows the site as not reuse ready.
The measurement point you fix in early 2027 shapes a public label for a year. Classes follow Annex I of the rating act.
Checklist: November 2026 to August 2027
November to December 2026
- List sites at or above 500 kW with ReferenceIDs, and check EU Login accounts belong to current staff.
- Ask your national contact point about national schemes and the 2027 template.
- Watch for Official Journal publication, or a scrutiny extension, after about 21 November.
January to February 2027
- Close out 2026 meter data for EDC, EIT, generators, water and heat.
- Collect guarantee of origin statements and PPA volumes with commissioning dates, and send tenant data requests.
March to April 2027
- Calculate the KPIs, map them to classes, check for template changes, validate XML locally and sign off the method.
By 15 May 2027
- Submit, download the confirmation copy and archive your workbook.
May to August 2027
- Answer Member State queries and prepare a label link. German sites also face the current PUE limit from 1 July 2027; see our guide to the EnEfG PUE cap.
How eCorpIT can help
eCorpIT is a Gurugram-based technology organisation, founded in 2021, assessed at CMMI Level 5 and MSME certified, with senior-led engineering teams working across AWS, Microsoft and Google platforms. Our data centre and cloud networking team can map your meters to the EU definitions, build the IT power and ICT capacity inventory, and turn meter, BMS and certificate data into a validated XML file. Talk to us at /contact-us/.
Last updated: 7 November 2026.
