Assessment of next steps to promote the energy performance and sustainability of data centres in EU, including the establishment of an EU-wide rating scheme - Second technical report

Overview

The report is the second deliverable of the technical assistance study supporting implementation of Article 12(5) of Directive (EU) 2023/1791, produced by EY, AIT and Borderstep for the European Commission (manuscript completed August 2025, dated October 2025). It covers three tasks: Task 2.1 the need for and implementation of a common EU rating scheme, Task 2.2 ways to improve energy efficiency including minimum performance standards, and Task 2.3 the feasibility of a transition to a net-zero emission data centre sector. The analysis uses data from 748 data centres reported under EED Article 12 and received by 24 April 2025; about 600 valid entries remained per indicator.

The rating work reviews existing certification and labelling schemes (for example the Blue Angel) and, through surveys, interviews and workshops, produces a four-section multi-criteria label draft: general information on top, upstream impacts on the left (origin of electricity and water), efficiency of the building, infrastructure and IT hardware in the centre, and downstream aspects (waste heat, hardware circularity) on the right. Because it relies on existing indicators it adds little burden; annual updates and machine-readable publication are suggested. Whether the label should be public is presented as a debated topic because of trade-secret concerns.

The MPS proposal focuses on three core indicators. For PUE: operational PUE below 1.5 by 2030 for centres commissioned before 2027, and design PUE below 1.3 with operational PUE below 1.4 within three years for centres commissioned from 2027. For WUE: below 0.4 m3/MWh by 2030 for existing and from 2027 for new centres, based on net water input (Category 2). For REF: 100% on an annual balance by 2030, with a future field for hourly matching. For ERF no uniform EU standard is proposed; a location-specific 'maximum possible ERF' (MaxERF) set by local authorities is used and the actual ERF is expressed against it.

The report states its limits clearly: the data belong to the first reporting cycle and are incomplete and inconsistent; stakeholders said at least two full reporting cycles are needed for MPS, that without climate normalisation operators in warm or water-stressed regions could be penalised, and that small and legacy sites are vulnerable. The report also proposes corrections to the reporting scheme: reported IT power should be rated power, water should be standardised to WUE Category 2 (EN 50600-4-9) and cooling degree days should be retrieved automatically from Eurostat.

Key points

1. Data from 748 data centres reported under EED Art. 12(5) (received by 24 April 2025) were analysed; about 600 valid entries remained per KPI.
2. Proposed PUE MPS: operational PUE < 1.5 by 2030 for DCs commissioned before 2027; design PUE < 1.3 and operational PUE < 1.4 within three years for DCs commissioned from 2027.
3. 56% of 600 entries already achieve PUE <= 1.5, including 49% of sites older than ten years and 46% of sites with CDD > 165.
4. Proposed WUE MPS: < 0.4 m3/MWh for existing DCs by 2030 and for new DCs from 2027, using Category 2 (net water input) reporting only; 72% of 421 entries already meet it.
5. A 25% local water-depletion threshold (WRI Aqueduct at NUTS3) is suggested to decide where the stricter WUE requirement should apply.
6. Weighted average REF across reported data is 86.8%; a target of REF = 100% (annual balance) by 2030 is proposed, with a future field for hourly-matched renewables.
7. Only 50 of 617 DCs reported any heat reuse (average outlet 25 C), so no EU-wide ERF MPS is recommended; instead ERF/MaxERF is set by local authorities.
8. The proposed label has four sections: general information on top, upstream impacts on the left, efficiency in the centre, downstream aspects and circularity on the right; it relies on existing indicators.
9. Reviewed schemes include rules where all cooling systems must use refrigerants with GWP < 150, and the Blue Angel sets PUE benchmarks down to 1.25.
10. MPS feasibility was tested across 27 data centre archetypes with selected best available techniques (BAT).

Using it in design

• Align the PUE target of new designs with the proposed MPS: design PUE below 1.3 and operational PUE below 1.4 in the first three years; for existing sites plan the path to below 1.5 by 2030.
• When choosing cooling technology calculate WUE on a net water input (Category 2) basis and treat the below-0.4 m3/MWh target as a stricter condition in water-scarce regions.
• Report rated power (UPS, fuse protection) as IT power; the report found installed power often wrongly stated (energy consumption exactly 8,760 times the connected load).
• Track renewable supply on an hourly-matching basis in addition to the annual balance; a reporting field will be added.
• Discuss waste heat reuse with the local authority in the MaxERF framework in advance, and know that without an off-taker it will be reported as not applicable (N/A).
• Check that cooling degree days (CDD) are consistent with the location-based value retrieved from Eurostat instead of entering them yourself; the report says CDD were often reported incorrectly.

Who should read it

Engineers, compliance and policy teams designing and operating data centres in the EU and preparing for rating and minimum performance standards.

Document contents

1. 1. Introduction: purpose, structure of the report, version control, acronyms, reference documents
2. 2. Methodologies: Task 2 - Next steps towards a sustainable data centre sector
3. 3. Study developments and results
4. Task 2.1 - Assess the need and propose ways to implement a possible common EU rating scheme
5. Task 2.2 - Assess the need and propose ways to improve energy efficiency, including minimum performance standards
6. Task 2.3 - Assess the feasibility of a transition towards a net-zero emission data centre sector
7. 4. Conclusions: the results in brief, summary of stakeholder feedback, recommendations for the data reporting scheme
8. Annex 1 - Surveys/interviews
9. Annex 2 - Detailed BAT rating
10. Annex 3 - Archetypes
11. Annex 4 - External standards, policies and initiatives

Related standards

• Directive (EU) 2023/1791
• Delegated Regulation (EU) 2024/1364
• EN 50600-4-2
• EN 50600-4-9
• ISO/IEC 30134

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Publication details

Authors

Simon Hinterholzer; Ralph Hintemann; Severin Beucker; Nicolas Marx; Patrik Furda; Dennis Heatubun; Ionut Dragan; Marco Bolchi; Patricia Lopes Bautista

Publisher

European Commission, DG ENER (AIT, Borderstep Institute, EY)

Year

2025

Document number

MJ-01-25-123-EN-N

Document language

English

Source type

Government / public

Access

Open licence — downloadable

DOI

10.2833/0828045

Licence

CC BY 4.0 — share with attribution

Licence evidence

op.europa.eu

Citation