Are Europe's data centres hiding their water use?

Of the 186 large data centres operating in the Netherlands by late 2025, just 44 had published their electricity use. Only 47 shared water figures. And that's the good news: the Netherlands is among Europe's more transparent countries.

The figures come from a Lighthouse Reports investigation of 500 kW-plus facilities. Operators must report water and energy use, renewable share, waste-heat use and cooling efficiency under EU rules. They do report, but to governments. If you're a resident, getting the numbers is far harder.

The group tried similar requests across all 27 EU member states. Many were denied because authorities said they didn't hold the information or called it confidential.

Instead of raw figures, the EU gives out efficiency ratings, similar to the ones on your domestic appliances. The rating informs you about the data centre's efficiency rating; it does not inform you about its energy or water consumption.

This is problematic because even the most energy-efficient hyperscale campus consumes enormous amounts of both. Lacking raw numbers, communities and policymakers cannot assess the data centre under consideration.

The NGO Lighthouse Reports claims that “the Commission has bowed to confidentiality clauses demanded by the industry.” In this regard, it has lodged a complaint against the EU in the framework of the Aarhus Convention.

Local planning fights are where this lands first. If you live near a proposed site, you'd be judging it on a label rather than on kilowatt-hours or litres.