Where is the best place to build a data centre?

A data centre consumes electricity, water for part of its cooling, and a place on the electricity grid; it gives off heat. The place where it is built determines the origin of its electricity, the climate that cools it, the water available, the capacity of the grid and whether there is an outlet for its heat. These 5 criteria cannot be measured on the same scale. For emissions, electricity weighs far more than climate; water is assessed river basin by river basin; the grid determines which locations are possible and the lead times.

The emissions counted here are those of the electricity consumed, converted using the average intensity of each country's grid. An operator may buy renewable electricity under contract; the contracts and grid chart shows the gap between the 2 accounts; the hub follows the actual grid.

In 2025, producing 1 kWh of electricity emitted 28 gCO2e in Norway, 41 in France and 589 in Poland, on a life-cycle basis. For 1 GWh consumed, this comes to 28 tonnes of CO2e in Norway, 41 in France, 330 in Germany and 589 in Poland: 14 times more in Poland than in France, 21 times more than in Norway; the countries chart gives the others. The hub tool repeats this calculation for a use of AI, with 12 countries and zones.

Low-carbon electricity can be scarce. A high share of nuclear, hydropower or wind does not mean that generation remains available for new centres: a large project may call on more emitting power stations in addition, in the country or among its neighbours.

A cold climate makes it possible to cool servers with outside air for a larger part of the year, and reduces the electricity used for cooling. The efficiency of a centre is measured by its power usage effectiveness (PUE): the total electricity of the site divided by that of the servers. In 2026, the average PUE reported to the Uptime Institute by operators around the world is 1.52.

At Google, whose European campuses are all in cool or temperate climates, total electricity varies by 3% from one campus to another. Between the industry average and the best of these campuses, it varies from 1 to 1.4. From one European electricity grid to another, the emissions of the same electricity vary from 1 to 21. None of these campuses is in Southern Europe: the sample does not measure the effect of a hot climate.

The water consumption of a centre depends on its cooling method. In 2025, Google's air-cooled campus in Dublin consumed 0.1 million gallons of water, a few hundred m³. The one at Saint-Ghislain, in Belgium, consumed 451 million, about 1.7 million m³: of the 714 million gallons it withdraws, it returns 264 million. The 2 campuses have the same PUE of 1.08. The volumes are not related to the electricity use of the sites, whose size differs.

The map of water stress shows where water is already under pressure. Saint-Ghislain is in Belgium, where withdrawals reach 53% of available resources, the highest level among the countries in the table; Norway is at 2%. These national averages hide the differences between river basins, which matter more for a given site.

The grid decides where a centre can connect and when. In the 5 large historic European hubs, Frankfurt, London, Amsterdam, Paris and Dublin, connecting a data centre takes 7 to 10 years on average, and up to 13 years, according to the think tank Ember.

Ireland shows what happens when projects are concentrated: data centres there consumed 23% of the electricity measured at meters in 2025, compared with 5% in 2015 (chart). A decision of the Irish regulator published on 12 December 2025 requires centres of at least 10 MVA to have dispatchable generation or storage, on site or nearby, in line with their connection capacity, and to cover at least 80% of their annual consumption with new renewable electricity produced in Ireland, within 6 years of being energised. In France, the Commission de régulation de l'énergie approved in May 2025 a fast-track connection procedure for consumers of 400 MW to 1 GW, for 2028-2029, on sites identified beforehand by the State.

Last criterion: the heat released has value only if a heat network exists nearby and has demand at the same time. The explainer on the heat of data centres shows why it remains little used in Europe.