EU Data Centre Reporting Under the EED: What to Report and When

Key takeaways

• Every EU data centre with at least 500 kW of installed IT power must report 7 items of site information and 24 key performance indicators to the European database each year, by 15 May, for the previous calendar year.
• Four indicators are calculated from those figures: PUE, WUE, the energy reuse factor (ERF) and the renewable energy factor (REF).
• Only 770 data centres reported in the first round, about 36% of the sites the Commission estimates were covered. The average reported PUE was 1.36.
• Individual site data in the European database is confidential; only Member State and EU aggregates are published. Operators still have their own duty to publish the Annex VII information, trade secrets excepted.
• On 21 September 2026 the Commission adopted the rating scheme and opened a consultation on minimum performance standards, open until 14 December 2026, with a proposal planned for the second quarter of 2027.

Only 770 data centres reported in the EU’s first round of mandatory energy reporting, about 36% of the sites the European Commission estimates were required to. Six Member States reported none at all. That is the Commission’s own count, in its report of 21 September 2026, and it matters for anyone running a European site, because the same data is now the basis for a rating scheme and, from 2027, for proposed minimum performance standards. This guide sets out who has to report under the EU Energy Efficiency Directive (EED), what goes into the report, when it is due, what becomes public, and how the four headline indicators are calculated, with a worked example for a 2 MW colocation site.

Does your data centre have to report under the EED?

Article 12 of Directive (EU) 2023/1791 applies to owners and operators of data centres with a power demand of the installed IT of at least 500 kW. The threshold is installed IT power, not the grid connection and not the average load, so a 2 MW hall running at half load is in scope. Sites below 500 kW are simply outside the scope; the Directive does not need an exemption for them. Data centres used for, or providing services exclusively for, defence and civil protection are excluded.

Watch the second 1 MW figure in the same Directive, because it measures something else. Article 26(6) requires data centres with a total rated energy input above 1 MW to use their waste heat, or other waste heat recovery applications, unless a cost-benefit assessment shows that is not technically or economically feasible. That test covers the whole facility’s energy input, not the IT load, and it is a separate duty from reporting.

Germany goes further. Its Energy Efficiency Act (EnEfG) defines a data centre from 300 kW of non-redundant rated connection power, required sites from 500 kW to report by 15 May 2024 and those from 200 kW to under 500 kW by 1 July 2025 (§20), and sets a national deadline of 31 March each year for the previous year’s information (§13). The national register then passes the data to the European database (§14). A German operator therefore works to two calendars.

What goes into the report: 7 items and 24 indicators

The Directive’s Annex VII sets out the principle in three short points. The operational detail is in Commission Delegated Regulation (EU) 2024/1364, which fixes exactly what operators send. Annex I asks for 7 items of site information: name, owner and operator, location, type of data centre (enterprise, colocation or co-hosting), date of entry into operation, and the redundancy level of the electrical and cooling infrastructure. Annex II lists 24 key performance indicators in three groups.

Two reliefs applied at the start. In the first reporting period an operator that could not measure some of the energy, water, heat and renewable indicators for technical reasons could omit them and explain why. For the first two periods, a colocation operator that could not gather its tenants’ data had to estimate and state the share of computer room floor area its figures cover. Both reliefs have now run out, so from the 15 May 2026 report onwards a colocation operator is expected to report the full set.

When the report is due, and to whom

The Directive’s text says 15 May 2024. In practice the first report was due on 15 September 2024, the date set by the Delegated Regulation, then 15 May 2025 and 15 May every year after that. Each report covers the calendar year before the reporting year, so the report due on 15 May 2027 covers 2026. Operators send it through their national reporting scheme where the Member State has set one up (Germany’s register is one), and directly to the European database otherwise.

What becomes public, and what stays confidential

There are two publication layers, and they are easy to confuse. The first is the operator’s own duty under Article 12(1) of the Directive: make the Annex VII information publicly available, except information protected as trade and business secrets under Union and national law. The second is the European database. Under Article 5 of the Delegated Regulation, the Commission and the Member States keep the data of individual data centres confidential, and the database publishes only aggregates at Member State and EU level, broken down by size class from 100 kW to over 10 MW. A competitor cannot look up your PUE in the EU database; whether it can find it on your own website depends on what you publish under Article 12(1).

Worked example: the four indicators for a 2 MW colocation site

Annex III of the Delegated Regulation defines four sustainability indicators as simple ratios of the reported figures: PUE = E_DC ÷ E_IT; WUE = water input ÷ E_IT, with E_IT in MWh; ERF = E_REUSE ÷ E_DC; and REF = total renewable energy ÷ E_DC. Two of them divide by IT energy and two by the whole facility’s energy, which is why a site can improve its PUE and see its ERF rise without reusing a single extra kilowatt-hour of heat.

Take an illustrative site, not a real one: 2,000 kW of installed IT power, an average IT load of 1,100 kW through 2026 and a facility running at a PUE of 1.40. The IT equipment uses 1,100 kW × 8,760 hours = 9,636,000 kWh, which is 9,636 MWh. The whole site uses 1.40 times that, 13,490,400 kWh. Assume it drew 5,300 m³ of water, delivered 400,000 kWh of heat to a neighbouring building, and covered 9,000,000 kWh with guarantees of origin, 3,000,000 kWh with a power purchase agreement and 150,000 kWh with rooftop solar.

Two things stand out. The PUE of 1.40 sits slightly worse than the EU average of 1.36, which is an average of the sites that reported, and the Commission counted only 681 of them as giving reliable PUE values. And the same site in Germany, if it entered operation before 1 July 2026, meets the EnEfG limit of 1.5 that applies from 1 July 2027 but not the 1.3 due from 1 July 2030 (§11). Getting there means cutting facility energy by 963,600 kWh a year at the same IT load, about 7% of the total. Our containment and liquid cooling worked case shows how far the usual retrofits move an existing air-cooled site.

What changed on 21 September 2026

The Commission published its assessment of the first reporting data on 21 September 2026, together with the second step of its three-step approach: a delegated regulation establishing a common Union rating scheme for data centres, built on the indicators already reported. The Commission states that the rating scheme adds no reporting burden for operators. The third step is minimum performance standards. A public consultation and call for evidence opened the same day and runs until 14 December 2026; the Commission plans to publish a proposal in the second quarter of 2027. Only 70.1% of the first round’s data was judged reliable, so the quality of what operators report now will shape the thresholds they are later held to.

If you are choosing where to build rather than reporting on a site you already run, our data-centre siting cost map compares electricity and connection costs across Europe.