Greenpeace study: German data centers used 13 billion liters of water in 2025

Water use by data centers

A study by the Öko-Institut, commissioned by Greenpeace and presented on Friday, 6 November 2026, puts the water used for cooling data centers in Germany in 2025 at about 13 billion liters. That volume equals roughly 70 percent of the water in the Pilsensee in Upper Bavaria. The researchers expect demand to rise sharply as new facilities come online, with up to 27 billion liters a year possible by 2030. The study compares that figure with the drinking water use of a city of about 580,000 inhabitants. For the 2025 volume alone, it cites a comparison with a city of 275,000 people.

2025 (consumed)13

2030 (possible, up to)27

2025 (consumed)

13 billion liters

2030 (possible, up to)

27 billion liters

Data from the article text

Planned mega facilities

Around 30 large data centers with more than 100 megawatts of server capacity are planned in Germany, according to the study. For one such 100 megawatt facility, annual water demand is estimated at 200 to 930 million liters, depending on the cooling technology used. That range corresponds to the drinking water use of a small town of up to 20,000 people. In regions that are already dry, the study warns, such facilities can cause acute groundwater stress, distribution conflicts and damage to local ecosystems.

Industry and researchers disagree

Bitkom, the digital industry association, has classed water demand as largely unproblematic. It says almost two-thirds of German facilities use at most 0.1 liters of water per kilowatt-hour of IT power, with relevant use mostly limited to evaporative cooling. The Öko-Institut, after removing faulty entries from the official data center register, arrives at a weighted average of 0.67 liters per kilowatt-hour. The study also disputes the industry argument that low power consumption must be paid for with higher water use, finding no statistical link between power and water efficiency. It adds that modern dry or compression cooling can bring direct water use down to zero.

Bitkom: upper figure for almost two-thirds of facilities0.1

Öko-Institut: weighted average0.67

Bitkom: upper figure for almost two-thirds of facilities

0.1 liters per kWh

Öko-Institut: weighted average

0.67 liters per kWh

Data from the article text

Cooling methods and local impact

Greenpeace says about a third of the roughly 1,200 data center operators in Germany use evaporative cooling, particularly in the summer months. In that process the drinking water escapes into the atmosphere as vapor and is no longer available to the local water cycle or to households. Greenpeace digital expert Linda Klapdor said the local consequences are already visible.

“The trend toward ever larger facilities with their enormous water consumption intensifies local water stress and triggers conflicts over use.”

Greenpeace demands that data centers in water-scarce regions be allowed to connect to the grid only with closed water circuits, and that their electricity come from renewable sources. The organization also says operators fulfill their duty to report water consumption only in part, that missing data is not systematically checked, and that binding caps on consumption do not exist. It further criticized the results report of the federal government's Digital Summit, which contains no energy, water or waste heat figures for the planned quadrupling of AI computing capacity.

Open day and disclosure checks

On Friday, 6 November 2026, the German Datacenter Association (GDA) holds its Tag der offenen Rechenzentren, with guided tours at 16 sites that visitors must register for in advance. The association says the day is meant to offer insight behind the scenes and more transparency. SWR Data Lab asked around 30 of the largest German operators for their figures. It found that more than half apparently do not meet the duty under the Energy Efficiency Act to publish electricity and water data, because the figures could not be found online and many operators did not respond or refused to provide them. Equinix, NTT and CloudHQ are among the operators named in the research.

Bernhard Wegener, professor of public law and European law at Friedrich-Alexander-Universität Erlangen-Nürnberg, judged the practice to be incompatible with the law.

“The Energy Efficiency Act is incompatible with this practice. The public has a claim to this data.”

The federal government wants to double data center capacity by 2030 to keep pace in the international race, and many new sites are rising in regions where groundwater is already becoming scarce. Bitkom puts the sector's share of Germany's total electricity at almost four percent. Julian Bothe of Algorithmwatch criticized the operators' lack of transparency, arguing that the country is facing an energy price crisis and a water crisis at the same time.