Energy Attribute Certificates · EU Policy Analysis
EU Draft Data Centre Rating Scheme Puts Granular Guarantees of Origin at the Centre of the Sustainability Label
On 26 March 2026, the European Commission registered a draft Delegated Regulation that will, once adopted, establish the first common EU rating scheme for data centres. The text — open for public feedback from 26 March to 23 April 2026 and scheduled for adoption in Q2 2026 — introduces an electronic sustainability label combining Power Usage Effectiveness (PUE), Water Usage Effectiveness (WUE), and a Renewable Energy Factor (REF). But the most consequential provision for energy buyers sits in Annex III: a redefinition of how Guarantees of Origin (GOs) can be counted, anchored in 15-minute matching, same-bidding-zone delivery, and a 10-year asset-age limit.
The draft is the second step of the framework set out under Article 33(3) of the recast Energy Efficiency Directive (EU) 2023/1791. Step one was Delegated Regulation (EU) 2024/1364, which created the European database on data centres and obliged operators with at least 500 kW of IT power demand to report key performance indicators. Step two adds a mandatory electronic label, generated automatically from data already in the database, and amends the underlying indicators — most notably the rules governing unbundled Guarantees of Origin.
Three renewable categories, three different tests
The label breaks a data centre's renewable share into three reported components — all carried over from the 2024 Regulation: E_RES-OS (on-site generation), E_RES-PPA (renewables via Power Purchase Agreement), and E_RES-GOO (renewable consumption claimed via unbundled GOs). The draft leaves the first two largely intact but rewrites the third, applying temporal, geographic, and asset-age filters that did not previously exist.
Table 1 · Treatment of renewable energy categories under the draft regulation
| Category | Definition | 15-min time matching | Same bidding zone | ≤10-year asset age |
|---|---|---|---|---|
| E_RES-OS | On-site renewable generation | Not applicable | Not applicable | Not applicable |
| E_RES-PPA | Renewables sourced via PPA | Not required | Not required | Not required |
| E_RES-GOO | Unbundled Guarantees of Origin | Required * | Required | Required (grandfathered for pre-15 May 2026 contracts) |
* Conditional to the availability of granular guarantees of origin in the relevant Member State. Source: Draft Delegated Regulation, Annex II point (p) and Annex III, Ref. Ares(2026)3247482.
How the label classifies energy efficiency
Beyond the renewable mix, the label assigns each reporting data centre to a Power Usage Effectiveness class on a seven-step A-to-G scale. A site achieving a PUE of 1.15 or below falls into Class A; anything above 1.9 lands in Class G. The thresholds are not arbitrary — they sit close to current best-available technology benchmarks, while Class G captures legacy facilities that have done little to optimise their cooling and power chains.
The Commission notes in its explanatory memorandum that improving a data centre's PUE from 1.6 to 1.2 — broadly, moving from a typical European average to current best practice — can reduce its electricity consumption by around 25 percent. With EU data centres projected to consume a steadily larger share of total electricity through 2030, the rating scheme is designed to make this efficiency gap visible to buyers, financiers, and regulators alike.
Chart 1 · PUE class thresholds (upper bound) under the draft Annex I
Source: Draft Delegated Regulation, Annex I, Table 1. Class G has no upper bound and is shown at 2.00 for illustrative purposes.
Water efficiency joins the rating
Annex I introduces a parallel A-to-G scale for Water Usage Effectiveness, calculated as the ratio of freshwater input to IT energy consumption. A Class A facility uses 0.1 cubic metres of freshwater per kilowatt-hour of IT load or less; Class G operators consume more than one cubic metre per kilowatt-hour. The Commission deliberately replaced "potable water" with "freshwater" to align with the Water Framework Directive and the European water resilience strategy — a quiet but consequential change for sites in water-stressed regions of southern Europe.
Chart 2 · WUE class thresholds (upper bound) under the draft Annex I
Source: Draft Delegated Regulation, Annex I, Table 2. Class G has no upper bound and is shown at 1.20 m³/kWh for illustrative purposes.
The consultation closed only days ago, and feedback from operator associations, the Association of Issuing Bodies, EnergyTag, and large energy buyers will likely shape the adopted text — particularly on cross-border bidding-zone treatment, storage allocation, and the practical readiness of national registries to issue 15-minute GOs at scale. For European data centre operators, however, the strategic message is already settled: the era of "annual matching as good enough" is closing, and procurement teams that have not yet engaged with granular GOs should treat 2026 as the year to start.