Water use and WUE — reading a Nordic climate claim

Reading order

Start with the water object, not with the climate slogan. Write whether anyone has named make-up water, humidification, evaporative rejection, a once-through loop, seawater, a municipal network or no on-site water at all. Then write whether the number, if any, is a design take, a measured year, or a marketing zero. Only then ask which metric name is in play. WUE is not PUE. Site WUE is not source WUE. The Green Grid’s litres per kilowatt-hour are not automatically the same cell as the Union reporting ratio of cubic metres to megawatt-hours.

Keep legal and technical sentences apart. Naturvårdsverket’s Environmental Code pages open if abstraction or discharge is vattenverksamhet. A WUE cell does not classify that activity. SMHI’s temperature series describe climate. They do not sign a cooling plant and they do not close a municipal water conversation. ASHRAE’s liquid-cooling vocabulary stays on the cooling page. Bidding areas SE1 to SE4 do not allocate litres.

Then classify the climate claim. Outdoor air in Luleå, seawater wording in Kista and a SMHI normal for a named station are three different objects. A northern winter can reduce mechanical-cooling hours. It does not prove a measured WUE of zero, and it does not travel to Staffanstorp as a permit.

• Name the water object before the climate slogan.
• Label design, measured or marketing.
• Keep Green Grid units, ISO KPI language and Union reporting cells apart.
• A SMHI normal is weather, not a permit.

What WUE actually measures

The Green Grid’s 2011 paper is the dated industry definition. WUE is annual water used on site — including humidification and water evaporated on site for energy production or cooling — divided by IT-equipment energy. WUEsource adds water used off site to produce the electricity. A hall that rejects heat only to outdoor air can still have humidification or a source-water cell. A zero on a slide that does not name the boundary is not a measured site WUE.

ISO/IEC 30134-9:2022 specifies WUE as a use-phase KPI, introduces measurement categories, and warns that the metric is not a standalone comprehensive efficiency score and does not account for water-quality change outside the data-centre boundary. The ISO landing page is a standard abstract. It is not a Swedish statutory table and this page will not reprint a paid standard as if it were a municipal decision.

Delegated Regulation (EU) 2024/1364 is a reporting rule. Article 1 sets the scope at an installed IT power demand of at least 500 kW. Annex language measures total water input W IN in cubic metres with CEN/CENELEC EN 50600-4-9 WUE Category 2, or Category 1 if needed, and potable water W IN-POT. The sustainability indicator is WUE = W IN / E IT with E IT in megawatt-hours. The public European database, the regulation says, is aggregated: Member State and Union averages for WUE, not a named Swedish hall litre. A reporting duty is not a measured Falun year.

The IEA’s 2025 report is useful because it refuses a single thirst number. Box 5.4 says water use varies with cooling technology, local climate and the electricity source; about two-thirds of 2023 global consumption sat with energy supply, about one quarter with direct cooling, and the rest with manufacturing. Direct-expansion cooling, the report says, is many times less water-intensive than airside economisers and adiabatic systems with water-cooled chillers. Those are IEA estimates. They are not a Swedish campus census and they are not a WUE for Meta’s Luleå page.

What named primary sources show

Meta’s cited Luleå page remains the clearest Swedish outdoor-air sentence in this register. It is an operator description of one northern campus operational from 2013, with local hydropower. It does not publish a WUE, an annual litre take, or a water-permit decision. The 2011 Associated Press notice about Arctic chill bringing Facebook to Sweden is a siting story. It is not a measured water year.

Digital Realty’s STO1 page says the Stockholm halls run cooling-free for over half the year using remote seawater cooling. That is operator language about a Kista plant. Seawater is still water. “Cooling-free” is not a WUE of zero and not proof that abstraction, discharge or a municipal network conversation is closed. STACK’s live STO01 campus page states 18 MW, eight acres and one building. It does not, on that page, publish a WUE. atNorth SWE01 names liquid cooling and Exergi recovery, not a litre balance. GleSYS’s 1 October 2020 Falkenberg notice is a heat-delivery start, not a water census.

SMHI’s temperature pages and its annual-and-monthly statistics are the official Swedish climate series. They publish station observations and normals on a 30-year World Meteorological Organization period. They do not publish a data-centre WUE and they do not replace a cooling drawing. The Commission energy-performance page already in this register remains reporting context, including the Union rating scheme. It does not fill a missing Swedish hall litre.

A matrix instead of a climate score

Draw one page with water states in rows and evidence in columns. No on-site water, humidification only, evaporative rejection, seawater or once-through, and a named Environmental Code paper are different rows. Design drawing, measured period, operator marketing and Union reporting are different columns. Empty cells stay empty. A Nordic winter is not a column.

Do not invent a Swedish WUE league table from Meta’s outdoor air, Digital Realty’s seawater sentence, atNorth’s liquid loop or the IEA’s US 100 MW example. Those remain different objects from different years and methods.

Common misreads

The first misread is to treat a Nordic winter as a water permit. SMHI series are climate. Naturvårdsverket still opens if the activity is classified. The second is to treat “cooling-free” or outdoor air as a measured WUE of zero. Humidification, seawater, make-up and source water can still sit in the file. The third is to paste the IEA’s two-million-litre US example onto Horndal, Falun or SWE04.

The fourth is to compare Green Grid L/kWh with the Union m³/MWh cell as if they were already the same number. The fifth is to treat an aggregated Member State WUE, once published, as a named hall result. The sixth is to use hydropower in Luleå as proof that the cooling loop uses no water. Fuel mix stays in the energy-mix cell.

What to ask next

Ask for the water object, the source, the annual and peak volumes, and whether any figure is designed or measured. Ask which WUE definition is in the slide — Green Grid site, Green Grid source, ISO category, or Union W IN / E IT — and for which period. Ask whether seawater or a municipal network is in the loop. Ask which Environmental Code paper, if any, has been opened.

Then open the parent cooling page, the water-and-cooling approvals page, the liquid-cooling page and the energy-efficiency page. If the operator will not name the litre or the rejection neighbour, record the gap. Do not fill it from a climate slogan or from an IEA US example.

1. Water object, source, annual and peak volumes.
2. WUE name, boundary, period and unit.
3. Design versus measured labelled.
4. Climate series kept as weather.
5. No invented Swedish WUE league table.

What this does and does not prove

This page proves that a Nordic climate is not a water exemption and not a WUE. It proves that The Green Grid published a 2011 site-versus-source definition, that ISO/IEC 30134-9 exists as a KPI standard, that the Union reporting rule uses W IN / E IT for halls at or above 500 kW IT demand, and that the IEA published global and US water estimates in April 2025.

It does not prove a best Swedish cooling water technology. It does not publish a national WUE, a Luleå litre year, or a Kista seawater permit. It does not treat Digital Realty’s “cooling-free” sentence as zero water. It does not convert operator PUE figures into water scores.

Unknown litres, unknown loops and unknown Environmental Code papers stay unknown. Point to the named source gap. Until a later primary source adds a measured Swedish WUE with a boundary and a year, the climate is weather rather than a water permit.