The European Commission's document, dated "Brussels, 14.3.2024" and numbered "C(2024) 1639 final," holds the "ANNEXES to the Delegated Act on the first phase of the establishment of a common Union rating scheme for data centres." The copy read is the one in the register of the Council of the European Union, under a cover note dated March 15, 2024. The articles of the delegated act are not in this document, so which data centers must report, and from what size, is not set out here. Parts of the annexes follow, not the whole.
What Is Measured, and Where
Annex II begins with record keeping. "For all monitoring, data centre operators shall keep a record of the measurement points and measurement devices used, for a period of at least ten years." Total energy consumption, which the annex shortens to EDC, is to be measured by the methodology of the CEN/CENELEC EN 50600-4-2 standard or equivalent, and "includes the use of electricity, fuels and other energy sources used for cooling." The part that comes from backup generators "shall be measured separately." The measurement is to be taken "at the input of the data centre system before the supply transfer switchgear," with measurement points at the primary and secondary supply of energy and at every additional supply, such as back-up generation.
The energy of information technology equipment, EIT, is to be measured as the combined annual energy consumption "at every uninterruptible power system (UPS) connected to data centre information technology equipment." Where a data center has no UPS, "for example, direct current data centres," EIT can be measured at the power distribution unit, or in accordance with the standard's category 2 methodology, "or at a measurement point that data centres will specify."
Where the meter sits decides what a score can show. A hall measured at a point it specifies itself reports a number a lender cannot assume is comparable with its neighbor's.
Water and Heat
Total water input, WIN, covers "all water volumes that enter the data centre boundary and are used in relation to the data centre functions including environmental, power, security, and information technology." It is to be measured by the methodology set out in the CEN/CENELEC EN 50600-4-9 standard, in its WUE Category 2, or if that is not possible, Category 1, or an equivalent standard.
Reused waste heat counts only when it is heat "used or reused outside of the data centre boundary, and which substitutes partly or totally energy needed outside the data centre boundary." If part of the waste heat is reused for cooling the data center itself, that part must be subtracted. The average waste heat temperature "shall be measured as the temperature of the fluid used to cool the information and communication technology equipment in the data centre computer room, averaged over the year, and across every measurement point."
The Scores
Annex III says its sustainability indicators "shall be calculated based on the information and key performance indicators communicated to the European database." Power Usage Effectiveness is total energy divided by the energy of information technology equipment, "PUE = EDC/EIT." Water Usage Effectiveness is "WUE = WIN/EIT," with EIT "expressed in MWh." The Energy Reuse Factor and the Renewable Energy Factor are both divided by total energy, "ERF = EREUSE/EDC" and "REF = ERES-TOT/EDC." The annexes set no value that an indicator must reach.
A score is a ratio, and a ratio says how effectively power and water are used, not how much. A lender weighing a hall's demand on the grid still has to read the totals beside it.
What Is Made Public
"Pursuant to Article 12 of Directive (EU) 2023/1791, the European database shall be publicly available on an aggregated level," Annex IV says, and "Data shall be available at two levels of aggregation, namely, at Member State level and Union level." Its size categories run by information technology installed power, from the one it calls "very small data centre," at 100 kW to 500 kW, to the one it calls "very large data centre," above 10 MW.
Average PUE, WUE, ERF and REF are to be public for all reporting data centers in a Member State's territory and in the Union's, and per type of data center and per size category. The averages are weighted, "using the total energy consumption as the weighting factor." At Member State level, figures per type and per size category "will be possible only if the respective category contains data from at least three data centres," the annex adds.